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Physiological Implications of Myocardial Scar Structure

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ABSTRACT

Once myocardium dies during a heart attack, it is replaced by scar tissue over the course of several weeks. The size, location, composition, structure, and mechanical properties of the healing scar are all critical determinants of the fate of patients who survive the initial infarction. While the central importance of scar structure in determining pump function and remodeling has long been recognized, it has proven remarkably difficult to design therapies that improve heart function or limit remodeling by modifying scar structure. Many exciting new therapies are under development, but predicting their long‐term effects requires a detailed understanding of how infarct scar forms, how its properties impact left ventricular function and remodeling, and how changes in scar structure and properties feed back to affect not only heart mechanics but also electrical conduction, reflex hemodynamic compensations, and the ongoing process of scar formation itself. In this article, we outline the scar formation process following a myocardial infarction, discuss interpretation of standard measures of heart function in the setting of a healing infarct, then present implications of infarct scar geometry and structure for both mechanical and electrical function of the heart and summarize experiences to date with therapeutic interventions that aim to modify scar geometry and structure. One important conclusion that emerges from the studies reviewed here is that computational modeling is an essential tool for integrating the wealth of information required to understand this complex system and predict the impact of novel therapies on scar healing, heart function, and remodeling following myocardial infarction. © 2015 American Physiological Society. Compr Physiol 5:1877‐1909, 2015.

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Figure 1. Figure 1. Wound healing after a myocardial infarction is a multifaceted, dynamic process that results in the replacement of necrotic myocytes with collagenous scar tissue. (A) This process is generally divided into (i) an early inflammatory phase characterized by pronounced chemical signaling, resorption of necrotic tissue, and recruitment of myofibroblasts, (ii) a fibrotic phase characterized by increased myofibroblast number and collagen accumulation, and (iii) a long‐term remodeling phase characterized by collagen matrix stabilization and maturation. Panel A adapted, with permission, from Jugdutt (127). (B) Components of infarct scar matrix are highly dynamic during the healing time course. Curves represent the fits of reported data, averaged across a number of small animal studies after grouping into the following categories: collagen (types I, III, IV, and VI) (29,36,39,73,123,176,183,190,273,279,293,301), collagen cross‐links (hydroxylysylpyridinium and hydroxylysylpyridinoline) (73,176,273,301), provisional structure (fibrin, fibronectin, and laminin) (39,58,139,162,183), matricellular proteins (tenascin‐C, thrombospondin, osteopontin, periostin, and SPARC) (76,119,144,162,193,195,238,264), glycosaminoglycans (hyaluronan) (58), and proteoglycans (biglycan and decorin) (62,284,292,301).
Figure 2. Figure 2. Infarct collagen orientation depends on imaging plane. (A) Infarcts are most often sectioned in the radial‐circumferential (i.e., short‐axis) plane, but fiber organization in the circumferential‐longitudinal plane (parallel to the epicardium) is more relevant to scar mechanics. (B) In the short‐axis view, collagen fibers lie in planes parallel to the epicardium and appear to be circumferentially aligned even when the circumferential‐longitudinal view (C) reveals them to be isotropic. Images are from 3‐week‐old rat infarcts, sectioned, stained with picrosirius red, and imaged under polarized light. Reprinted, with permission, from Fomovsky (75).
Figure 3. Figure 3. Correlation between infarct mechanics and scar collagen structure in healing rat infarcts (75). (A, B) Diagrams showing location of infarcts following permanent ligation or cryoinfarction to create infarcts with a range of shapes and locations: circular‐apex (C‐A), circular‐midequator (C‐M), circumferential ellipse (CE) at the equator, or longitudinal ellipse (LE) at the equator. (C, D) Circumferential and longitudinal systolic strains were negative prior to infarction (control), indicating contraction. During acute ischemia, apical infarcts stretched during systole in both directions (C); by contrast, infarcts at the equator stretched only in the circumferential direction (D). (E, F) Mean collagen orientation histograms show isotropic structure in apical infarcts (E) and circumferential alignment in equatorial infarcts (F).
Figure 4. Figure 4. Chronic infarct geometric measurements demonstrate substantial remodeling in the circumferential dimension. (A) When assessed in vivo, studies sometimes report infarct expansion (increase in the scar's circumferential length) and sometimes report compaction (decrease in the scar's circumferential length). (B) When assessed in excised, arrested hearts (i.e., no longer pressurized), studies typically report compaction. These trends are true across multiple animal models and measurement techniques.
Figure 5. Figure 5. Data from Pfeffer et al. on remodeling of end‐diastolic pressure‐volume relationship following myocardial infarction in rats (205). Following small infarcts (those affecting 5‐30% of the LV circumference), effects of changes in infarct stiffness and cavity dimension offset, producing little change in the end‐diastolic pressure‐volume relationship (EDPVR) from 6 h (1/4 day) to 15 weeks (106 days). By contrast, substantial cavity dilation led to a progressive rightward shift of the EDPVR following larger infarcts. Small numbers at the top of each curve indicate the time postinfarction; error bars are 2*SE for group sizes of 5 to 10 at most time points and 12 to 25 at the last two time points. Figure slightly modified with permission from Pfeffer et al. (205).
Figure 6. Figure 6.

Effect of acute ischemia on the end‐systolic pressure‐volume relationship (ESPVR). (A) Plots from Sunagawa et al. showing a progressive rightward shift in the ESPVR as ischemic regions of increasing size were created in 6 dog hearts [reprinted with permission (252)].

A—control; B—distal left circumflex (LCx) artery occlusion; C—proximal left anterior descending (LAD) artery occlusion; D—proximal LCx occlusion; E—distal LAD occlusion; F—mid‐LAD occlusion; G—end‐diastolic pressure volume relationship (EDPVR). (B) Illustration of the compartmental model proposed by Sunagawa et al., for an ischemic region affecting 40% of LV mass. The model predicts the ischemic ESPVR as a weighted average of the normal ESPVR and the EDPVR, which is assumed to reflect the passive mechanical behavior of the acutely ischemic region.

Figure 7. Figure 7. Changes in pressure‐segment length curves during acute ischemia. (A) Pressure‐circumferential segment length loops recorded in our laboratory from an open‐chest anesthetized dog with autonomic reflexes pharmacologically blocked. Fifteen minutes of ischemia converted the active loop to an exponential, passive curve, induced a rightward shift, and increased end‐diastolic pressure (EDP). (B) Pressure‐longitudinal segment length loops recorded in our laboratory from an open‐chest anesthetized rat with intact autonomic reflexes. Thirty minutes of ischemia converted the active loop to a passive curve and increased EDP, shifting the segment onto a steeper region of that curve. Blue triangles—control end diastole (ED); blue circles—control end systole (ES); red triangles—ischemia ED; red circles—ischemic ES.
Figure 8. Figure 8. Changes in regional mechanics during infarct healing. (A) Circumferential strains reflecting deformation from end diastole to end systole measured using radiopaque markers [pig, Holmes et al. (114)] or sonomicrometers [rat, Fomovsky et al. (73); dog, Theroux et al. (259,260)] drop to near zero acutely and remain small (usually not significantly different from zero) for several weeks after infarction in most studies. However, Theroux and co‐workers found that shortening partly recovered in dogs with reperfused infarcts (closed squares), in contrast to dogs with permanent ligation studied using otherwise identical methods (open squares). (B) Circumferential strains measured using MRI showed gradual recovery in patients with reperfused MI [black curves (22,136,148,229)] but not in mice with reperfused MI (296), or sheep with permanent ligations (147).
Figure 9. Figure 9.

Effect of infarct size on left ventricular remodeling. (A) Measurements of LV remodeling 1 year post‐MI in patients revealed that end systolic volume is linearly related to acute infarct size. Plot reprinted, with permission, from Chareonthaitawee et al. (41).

(B) End‐diastolic pressure‐volume relationship (EDPVRs) of rats with a healed myocardial infarction (MI) were generated by passive inflation of the arrested left ventricle (LV). Shifts in the average curves show that for a given LV pressure (LVP), LV cavity volume increases monotonically with infarct size. Plot reprinted, with permission, from Fletcher et al. (71).

Figure 10. Figure 10. Effects of infarct mechanical properties on passive and active left ventricular function. (A, B) Original model results reprinted with permission from Bogen (23). (A) Immediately post‐MI, the noncontractile ischemic area causes severe systolic dysfunction [characterized by a rightward shift in the end‐systolic pressure‐volume relationship (ESPVR)] with minimal effect on passive LV behavior. Systolic function improves (ESPVR shifts leftward toward baseline) as the infarct stiffens throughout healing, but the stiffer scar also impairs diastolic filling [steepening of the end‐dystolic pressure‐volume relationship (EDPVR)]. (B) Unfortunately, similar magnitude shifts in these two curves can offset each other, leading to minimal improvement in stroke volume as the scar stiffens. (C, D) Experimental results reprinted, with permission, from Fomovsky (72). (C) Changes in passive and active LV behavior with infarction and anisotropic infarct reinforcement. Selective longitudinal reinforcement shifts the ESPVR leftward with minimal effect on the EDPVR. (D) Anisotropic infarct reinforcement improves systolic function without impairing diastolic filling, leading to better pump function as indicated by an upward shift in the CO curve.
Figure 11. Figure 11. (A) Three‐dimensional reconstruction of an infarcted region (2.99 × 2.68 × 0.70 mm3 volume). (B) Representative activation pathways with stimulation at the subendocardium (top) or subepicardium (bottom), demonstrating tortuous stimulus site‐dependent activation pathways through the infarct. (C) Sustained reentry in the infarcted region induced by a stimulus train with reducing cycle length applied at the subepicardium (red sphere). The subepicardium and subendocardium were coupled at the network boundary via a path (dashed line) that imposed a time delay. Shown are activation maps for beats 1 to 6 (beats 1‐2 were paced with a cycle length of 157 ms, then, following unidirectional block, reentrant activation occurred in beats 3‐6). The marker • indicates the basal subepicardium and is used as a fiducial reference. Modified, with permission, from Rutherford et al. (233).
Figure 12. Figure 12. Effect of various therapeutic modulations on collagen content post‐myocardial infarction (post‐MI). Both pharmacologic and genetic perturbations have been utilized to significantly modify the collagen content within myocardial scar. Some of these effects resulted from intentional modulation of collagen synthesis or matrix metalloproteinase (MMP)‐mediated degradation within the scar [e.g., via prolyl‐4‐hydroxylase, MMP, or tissue inhibitor of MMPs (TIMP) activity], while some resulted as biproducts of modulating remote cardiomyocyte signaling (e.g., via angiotensin or beta‐adrenergic pathways). Bars represent means and standard deviations across available studies (see text for references).
Figure 13. Figure 13. (A) Isochronal map generated from epicardial sock data (black dots indicate location of the electrodes) during reentry (left) and signals from bipolar electrograms at respective locations showing progression of electrical activation traveling from point A to I (right). (B) Three‐dimensional infarct geometry reconstructed from high‐resolution contrast‐enhanced magnetic resonance imaging (0.39 × 0.39 × 0.39 mm spatial resolution). The infarcted region is represented by dark gray and the normal myocardium by pink. Islands of viable myocardium within the scar, as well as islands of scar within the viable myocardium, are present. (C) Combined electrical and structural data showing the reentrant isthmus located at the postero‐apical segment of the infarcted region (circumscribed by a broken red line). The scar geometry at the isthmus was characterized by scar tissue interspersed with multiple tracts of viable myocardium. Possible electrical propagation at the infarct border zone is indicated by the dashed red arrow. Modified, with permission, from Ashikaga et al. (6).


Figure 1. Wound healing after a myocardial infarction is a multifaceted, dynamic process that results in the replacement of necrotic myocytes with collagenous scar tissue. (A) This process is generally divided into (i) an early inflammatory phase characterized by pronounced chemical signaling, resorption of necrotic tissue, and recruitment of myofibroblasts, (ii) a fibrotic phase characterized by increased myofibroblast number and collagen accumulation, and (iii) a long‐term remodeling phase characterized by collagen matrix stabilization and maturation. Panel A adapted, with permission, from Jugdutt (127). (B) Components of infarct scar matrix are highly dynamic during the healing time course. Curves represent the fits of reported data, averaged across a number of small animal studies after grouping into the following categories: collagen (types I, III, IV, and VI) (29,36,39,73,123,176,183,190,273,279,293,301), collagen cross‐links (hydroxylysylpyridinium and hydroxylysylpyridinoline) (73,176,273,301), provisional structure (fibrin, fibronectin, and laminin) (39,58,139,162,183), matricellular proteins (tenascin‐C, thrombospondin, osteopontin, periostin, and SPARC) (76,119,144,162,193,195,238,264), glycosaminoglycans (hyaluronan) (58), and proteoglycans (biglycan and decorin) (62,284,292,301).


Figure 2. Infarct collagen orientation depends on imaging plane. (A) Infarcts are most often sectioned in the radial‐circumferential (i.e., short‐axis) plane, but fiber organization in the circumferential‐longitudinal plane (parallel to the epicardium) is more relevant to scar mechanics. (B) In the short‐axis view, collagen fibers lie in planes parallel to the epicardium and appear to be circumferentially aligned even when the circumferential‐longitudinal view (C) reveals them to be isotropic. Images are from 3‐week‐old rat infarcts, sectioned, stained with picrosirius red, and imaged under polarized light. Reprinted, with permission, from Fomovsky (75).


Figure 3. Correlation between infarct mechanics and scar collagen structure in healing rat infarcts (75). (A, B) Diagrams showing location of infarcts following permanent ligation or cryoinfarction to create infarcts with a range of shapes and locations: circular‐apex (C‐A), circular‐midequator (C‐M), circumferential ellipse (CE) at the equator, or longitudinal ellipse (LE) at the equator. (C, D) Circumferential and longitudinal systolic strains were negative prior to infarction (control), indicating contraction. During acute ischemia, apical infarcts stretched during systole in both directions (C); by contrast, infarcts at the equator stretched only in the circumferential direction (D). (E, F) Mean collagen orientation histograms show isotropic structure in apical infarcts (E) and circumferential alignment in equatorial infarcts (F).


Figure 4. Chronic infarct geometric measurements demonstrate substantial remodeling in the circumferential dimension. (A) When assessed in vivo, studies sometimes report infarct expansion (increase in the scar's circumferential length) and sometimes report compaction (decrease in the scar's circumferential length). (B) When assessed in excised, arrested hearts (i.e., no longer pressurized), studies typically report compaction. These trends are true across multiple animal models and measurement techniques.


Figure 5. Data from Pfeffer et al. on remodeling of end‐diastolic pressure‐volume relationship following myocardial infarction in rats (205). Following small infarcts (those affecting 5‐30% of the LV circumference), effects of changes in infarct stiffness and cavity dimension offset, producing little change in the end‐diastolic pressure‐volume relationship (EDPVR) from 6 h (1/4 day) to 15 weeks (106 days). By contrast, substantial cavity dilation led to a progressive rightward shift of the EDPVR following larger infarcts. Small numbers at the top of each curve indicate the time postinfarction; error bars are 2*SE for group sizes of 5 to 10 at most time points and 12 to 25 at the last two time points. Figure slightly modified with permission from Pfeffer et al. (205).


Figure 6.

Effect of acute ischemia on the end‐systolic pressure‐volume relationship (ESPVR). (A) Plots from Sunagawa et al. showing a progressive rightward shift in the ESPVR as ischemic regions of increasing size were created in 6 dog hearts [reprinted with permission (252)].

A—control; B—distal left circumflex (LCx) artery occlusion; C—proximal left anterior descending (LAD) artery occlusion; D—proximal LCx occlusion; E—distal LAD occlusion; F—mid‐LAD occlusion; G—end‐diastolic pressure volume relationship (EDPVR). (B) Illustration of the compartmental model proposed by Sunagawa et al., for an ischemic region affecting 40% of LV mass. The model predicts the ischemic ESPVR as a weighted average of the normal ESPVR and the EDPVR, which is assumed to reflect the passive mechanical behavior of the acutely ischemic region.



Figure 7. Changes in pressure‐segment length curves during acute ischemia. (A) Pressure‐circumferential segment length loops recorded in our laboratory from an open‐chest anesthetized dog with autonomic reflexes pharmacologically blocked. Fifteen minutes of ischemia converted the active loop to an exponential, passive curve, induced a rightward shift, and increased end‐diastolic pressure (EDP). (B) Pressure‐longitudinal segment length loops recorded in our laboratory from an open‐chest anesthetized rat with intact autonomic reflexes. Thirty minutes of ischemia converted the active loop to a passive curve and increased EDP, shifting the segment onto a steeper region of that curve. Blue triangles—control end diastole (ED); blue circles—control end systole (ES); red triangles—ischemia ED; red circles—ischemic ES.


Figure 8. Changes in regional mechanics during infarct healing. (A) Circumferential strains reflecting deformation from end diastole to end systole measured using radiopaque markers [pig, Holmes et al. (114)] or sonomicrometers [rat, Fomovsky et al. (73); dog, Theroux et al. (259,260)] drop to near zero acutely and remain small (usually not significantly different from zero) for several weeks after infarction in most studies. However, Theroux and co‐workers found that shortening partly recovered in dogs with reperfused infarcts (closed squares), in contrast to dogs with permanent ligation studied using otherwise identical methods (open squares). (B) Circumferential strains measured using MRI showed gradual recovery in patients with reperfused MI [black curves (22,136,148,229)] but not in mice with reperfused MI (296), or sheep with permanent ligations (147).


Figure 9.

Effect of infarct size on left ventricular remodeling. (A) Measurements of LV remodeling 1 year post‐MI in patients revealed that end systolic volume is linearly related to acute infarct size. Plot reprinted, with permission, from Chareonthaitawee et al. (41).

(B) End‐diastolic pressure‐volume relationship (EDPVRs) of rats with a healed myocardial infarction (MI) were generated by passive inflation of the arrested left ventricle (LV). Shifts in the average curves show that for a given LV pressure (LVP), LV cavity volume increases monotonically with infarct size. Plot reprinted, with permission, from Fletcher et al. (71).



Figure 10. Effects of infarct mechanical properties on passive and active left ventricular function. (A, B) Original model results reprinted with permission from Bogen (23). (A) Immediately post‐MI, the noncontractile ischemic area causes severe systolic dysfunction [characterized by a rightward shift in the end‐systolic pressure‐volume relationship (ESPVR)] with minimal effect on passive LV behavior. Systolic function improves (ESPVR shifts leftward toward baseline) as the infarct stiffens throughout healing, but the stiffer scar also impairs diastolic filling [steepening of the end‐dystolic pressure‐volume relationship (EDPVR)]. (B) Unfortunately, similar magnitude shifts in these two curves can offset each other, leading to minimal improvement in stroke volume as the scar stiffens. (C, D) Experimental results reprinted, with permission, from Fomovsky (72). (C) Changes in passive and active LV behavior with infarction and anisotropic infarct reinforcement. Selective longitudinal reinforcement shifts the ESPVR leftward with minimal effect on the EDPVR. (D) Anisotropic infarct reinforcement improves systolic function without impairing diastolic filling, leading to better pump function as indicated by an upward shift in the CO curve.


Figure 11. (A) Three‐dimensional reconstruction of an infarcted region (2.99 × 2.68 × 0.70 mm3 volume). (B) Representative activation pathways with stimulation at the subendocardium (top) or subepicardium (bottom), demonstrating tortuous stimulus site‐dependent activation pathways through the infarct. (C) Sustained reentry in the infarcted region induced by a stimulus train with reducing cycle length applied at the subepicardium (red sphere). The subepicardium and subendocardium were coupled at the network boundary via a path (dashed line) that imposed a time delay. Shown are activation maps for beats 1 to 6 (beats 1‐2 were paced with a cycle length of 157 ms, then, following unidirectional block, reentrant activation occurred in beats 3‐6). The marker • indicates the basal subepicardium and is used as a fiducial reference. Modified, with permission, from Rutherford et al. (233).


Figure 12. Effect of various therapeutic modulations on collagen content post‐myocardial infarction (post‐MI). Both pharmacologic and genetic perturbations have been utilized to significantly modify the collagen content within myocardial scar. Some of these effects resulted from intentional modulation of collagen synthesis or matrix metalloproteinase (MMP)‐mediated degradation within the scar [e.g., via prolyl‐4‐hydroxylase, MMP, or tissue inhibitor of MMPs (TIMP) activity], while some resulted as biproducts of modulating remote cardiomyocyte signaling (e.g., via angiotensin or beta‐adrenergic pathways). Bars represent means and standard deviations across available studies (see text for references).


Figure 13. (A) Isochronal map generated from epicardial sock data (black dots indicate location of the electrodes) during reentry (left) and signals from bipolar electrograms at respective locations showing progression of electrical activation traveling from point A to I (right). (B) Three‐dimensional infarct geometry reconstructed from high‐resolution contrast‐enhanced magnetic resonance imaging (0.39 × 0.39 × 0.39 mm spatial resolution). The infarcted region is represented by dark gray and the normal myocardium by pink. Islands of viable myocardium within the scar, as well as islands of scar within the viable myocardium, are present. (C) Combined electrical and structural data showing the reentrant isthmus located at the postero‐apical segment of the infarcted region (circumscribed by a broken red line). The scar geometry at the isthmus was characterized by scar tissue interspersed with multiple tracts of viable myocardium. Possible electrical propagation at the infarct border zone is indicated by the dashed red arrow. Modified, with permission, from Ashikaga et al. (6).
References
 1. Amigoni M , Meris A , Thune JJ , Mangalat D , Skali H , Bourgoun M , Warnica JW , Barvik S , Arnold JMO , Velazquez EJ , Van de Werf F , Ghali J , McMurray JJV , Køber L , Pfeffer MA , Solomon SD . Mitral regurgitation in myocardial infarction complicated by heart failure, left ventricular dysfunction, or both: Prognostic significance and relation to ventricular size and function. Eur Heart J 28: 326‐333, 2007.
 2. Antoni ML , Boden H , Hoogslag GE , Ewe SH , Auger D , Holman ER , van der Wall EE , Schalij MJ , Bax JJ , Delgado V . Prevalence of dyssynchrony and relation with long‐term outcome in patients after acute myocardial infarction. Am J Cardiol 108: 1689‐1696, 2011.
 3. Arevalo H , Plank G , Helm P , Halperin H , Trayanova N . Tachycardia in post‐infarction hearts: Insights from 3D image‐based ventricular models. PLoS One 8: e68872, 2013.
 4. Aronson D , Goldsher N , Zukermann R , Kapeliovich M , Lessick J , Mutlak D , Dabbah S , Markiewicz W , Beyar R , Hammerman H , Reisner S , Agmon Y . Ischemic mitral regurgitation and risk of heart failure after myocardial infarction. Arch Intern Med 166: 2362‐2368, 2006.
 5. Arruda M , Fahmy T , Armaganijan L , Di Biase L , Patel D , Natale A . Endocardial and epicardial mapping and catheter ablation of post myocardial infarction ventricular tachycardia: A substrate modification approach. J Interv Card Electrophysiol 28: 137‐145, 2010.
 6. Ashikaga H , Sasano T , Dong J , Zviman MM , Evers R , Hopenfeld B , Castro V , Helm RH , Dickfeld T , Nazarian S , Donahue JK , Berger RD , Calkins H , Abraham MR , Marbán E , Lardo AC , McVeigh ER , Halperin HR . Magnetic resonance‐based anatomical analysis of scar‐related ventricular tachycardia: Implications for catheter ablation. Circ Res 101: 939‐947, 2007.
 7. De Bakker JM , van Capelle FJ , Janse MJ , Tasseron S , Vermeulen JT , de Jonge N , Lahpor JR . Slow conduction in the infarcted human heart. “Zigzag” course of activation. Circulation 88: 915‐926, 1993.
 8. De Bakker JM , van Capelle FJ , Janse MJ , Wilde AA , Coronel R , Becker AE , Dingemans KP , van Hemel NM , Hauer RN . Reentry as a cause of ventricular tachycardia in patients with chronic ischemic heart disease: Electrophysiologic and anatomic correlation. Circulation 77: 589‐606, 1988.
 9. De Bakker JM , Coronel R , Tasseron S , Wilde AA , Opthof T , Janse MJ , van Capelle FJ , Becker AE , Jambroes G . Ventricular tachycardia in the infarcted, Langendorff‐perfused human heart: Role of the arrangement of surviving cardiac fibers. J Am Coll Cardiol 15: 1594‐1607, 1990.
 10. De Bakker JMT , van Rijen HMV . Continuous and discontinuous propagation in heart muscle. J Cardiovasc Electrophysiol 17: 567‐573, 2006.
 11. De Bakker JMT , van Rijen HVM . Electrocardiographic manifestation of anatomical substrates underlying post‐myocardial infarction tachycardias. J Electrocardiol 40: S21‐S25, 2007.
 12. Barandon L , Couffinhal T , Ezan J , Dufourcq P , Costet P , Alzieu P , Leroux L , Moreau C , Dare D , Duplàa C . Reduction of infarct size and prevention of cardiac rupture in transgenic mice overexpressing FrzA. Circulation 108: 2282‐2289, 2003.
 13. Barzilai B , Davis VG , Stone PH , Jaffe AS , Group MS . Prognostic significance of mitral regurgitation in acute myocardial infarction. Am J Cardiol 65: 1169‐1175, 1990.
 14. Becker RC , Gore JM , Lambew C , Weaver WD , Rubison RM , French WJ , Tiefenbrunn AJ , Bowlby LJ , Rogers WJ . A composite view of cardiac rupture in the United States National Registry of Myocardial Infarction. J Am Coll Cardiol 27: 1321‐1326, 1996.
 15. Ben‐Mordechai T , Holbova R , Landa‐Rouben N , Harel‐Adar T , Feinberg MS , Abd Elrahman I , Blum G , Epstein FH , Silman Z , Cohen S , Leor J . Macrophage subpopulations are essential for infarct repair with and without stem cell therapy. J Am Coll Cardiol 62: 1890‐1901, 2013.
 16. Bilchick KC , Kuruvilla S , Hamirani YS , Ramachandran R , Clarke SA , Parker KM , Stukenborg GJ , Mason P , Ferguson JD , Moorman JR , Malhotra R , Mangrum JM , Darby AE , Dimarco J , Holmes JW , Salerno M , Kramer CM , Epstein FH . Impact of mechanical activation, scar, and electrical timing on cardiac resynchronization therapy response and clinical outcomes. J Am Coll Cardiol 63: 1657‐66, 2014.
 17. Birnbaum Y , Chamoun AJ , Conti VR , Uretsky BF . Mitral regurgitation following acute myocardial infarction. Coron Artery Dis 13: 337‐344, 2002.
 18. Bishop JE , Greenbaum R , Gibson DG , Yacoub M , Laurent GJ . Enhanced deposition of predominantly type I collagen in myocardial disease. J Mol Cell Cardiol 22: 1157‐1165, 1990.
 19. Blankesteijn WM , Creemers E , Lutgens E , Cleutjens JP , Daemen MJ , Smits JF . Dynamics of cardiac wound healing following myocardial infarction: Observations in genetically altered mice. Acta Physiol Scand 173: 75‐82, 2001.
 20. Blom AS , Mukherjee R , Pilla JJ , Lowry AS , Yarbrough WM , Mingoia JT , Hendrick JW , Stroud RE , McLean JE , Affuso J , Gorman RC , Gorman JH , Acker Ma, Spinale FG . Cardiac support device modifies left ventricular geometry and myocardial structure after myocardial infarction. Circulation 112: 1274‐1283, 2005.
 21. Blom AS , Pilla JJ , Arkles J , Dougherty L , Ryan LP , Gorman JH , Acker MA , Gorman RC . Ventricular restraint prevents infarct expansion and improves borderzone function after myocardial infarction: A study using magnetic resonance imaging, three‐dimensional surface modeling, and myocardial tagging. Ann Thorac Surg 84: 2004‐2010, 2007.
 22. Bogaert J , Maes A , Van de Werf F , Bosmans H , Herregods MC , Nuyts J , Desmet W , Mortelmans L , Marchal G , Rademakers FE . Functional recovery of subepicardial myocardial tissue in transmural myocardial infarction after successful reperfusion: An important contribution to the improvement of regional and global left ventricular function. Circulation 99: 36‐43.
 23. Bogen DK , Rabinowitz SA , Needleman A , McMahon TA , Abelmann WH . An analysis of the mechanical disadvantage of myocardial infarction in the canine left ventricle. Circ Res 47: 728‐741, 1980.
 24. Van den Borne SWM , van de Schans VaM , Strzelecka AE , Vervoort‐Peters HTM , Lijnen PM , Cleutjens JPM , Smits JFM , Daemen MJaP , Janssen BJa , Blankesteijn WM . Mouse strain determines the outcome of wound healing after myocardial infarction. Cardiovasc Res 84: 273‐282, 2009.
 25. Van den Bos EJ , Mees BME , de Waard MC , de Crom R , Duncker DJ . A novel model of cryoinjury‐induced myocardial infarction in the mouse: A comparison with coronary artery ligation. Am J Physiol Heart Circ Physiol 289: H1291‐H1300, 2005.
 26. Bristow MR , Ginsburg R , Minobe W , Cubicciotti RS , Sageman S , Lurie K , Billingham ME , Harrison DC , Stinson EB . Decreased catecholamine sensitivity and B‐adrenergic‐receptor density in failing human hearts. N Engl J Med 307: 205‐211, 1982.
 27. Brown EJ , Kloner RA , Schoen FJ , Hammerman H , Hale S , Braunwald E . Scar thinning due to ibuprofen administration after experimental myocardial infarction. Am J Cardiol 51: 877‐883, 1983.
 28. Brown EJ , Swinford RD , Gadde P , Lillis O . Acute effects of delayed reperfusion on myocardial infarct shape and left ventricular volume: A potential mechanism of additional benefits from thrombolytic therapy. J Am Coll Cardiol 17: 1641‐1650, 1991.
 29. Bryant JE , Shamhart PE , Luther DJ , Olson ER , Koshy JC , Costic DJ , Mohile MV , Dockry M , Doane KJ , Meszaros JG . Cardiac myofibroblast differentiation is attenuated by alpha(3) integrin blockade: Potential role in post‐MI remodeling. J Mol Cell Cardiol 46: 186‐192, 2009.
 30. Burkhoff D , Tyberg JV . Why does pulmonary venous pressure rise after onset of LV dysfunction: A theoretical analysis. Am J Physiol 265: H1819‐H1828, 1993.
 31. Bursi F , Enriquez‐Sarano M , Jacobsen SJ , Roger VL . Mitral regurgitation after myocardial infarction: A review. Am J Med 119: 103‐112, 2006.
 32. Bursi F , Enriquez‐Sarano M , Nkomo VT , Jacobsen SJ , Weston Sa , Meverden Ra , Roger VL . Heart failure and death after myocardial infarction in the community: The emerging role of mitral regurgitation. Circulation 111: 295‐301, 2005.
 33. Caldwell BJ , Trew ML , Sands GB , Hooks DA , LeGrice IJ , Smaill BH . Three distinct directions of intramural activation reveal nonuniform side‐to‐side electrical coupling of ventricular myocytes. Circ Arrhythm Electrophysiol 2: 433‐440, 2009.
 34. Calkins H , Maughan WL , Weisman HF , Sugiura S , Sagawa K , Levine JH . Effect of acute volume load on refractoriness and arrhythmia development in isolated, chronically infarcted canine hearts. Circulation 79: 687‐697, 1989.
 35. Cannom DS , Levy W , Cohen LS . The short‐ and long‐term prognosis of patients with transmural and nontransmural myocardial infarction. Am J Med 61: 452‐458, 1976.
 36. Cannon RO , Butany JW , McManus BM , Speir E , Kravitz AB , Bolli R , Ferrans VJ . Early degradation of collagen after acute myocardial infarction in the rat. Am J Cardiol 52: 390‐395, 1983.
 37. Cao J , Fu L , Gao Q , Xie R , Qu F . Streptomycin inhibits electrophysiological changes induced by stretching of chronically infarcted rat hearts. J Zhejiang Univ Sci B 15: 515‐521, 2014.
 38. Caorsi V , Toepfer C , Sikkel MB , Lyon AR , MacLeod K , Ferenczi Ma . Non‐linear optical microscopy sheds light on cardiovascular disease. PLoS One 8: e56136, 2013.
 39. Carlyle WC , Jacobson AW , Judd DL , Tian B , Chu C , Hauer KM , Hartman MM , Mcdonald KM . Delayed reperfusion alters matrix metalloproteinase activity and fibronectin mRNA expression in the infarct zone of the ligated rat heart. J Mol Cell Cardiol 2463: 2451‐2463, 1997.
 40. Chachques JC , Trainini JC , Lago N , Cortes‐Morichetti M , Schussler O , Carpentier A . Myocardial assistance by grafting a new bioartificial upgraded myocardium (MAGNUM trial): Clinical feasibility study. Ann Thorac Surg 85: 901‐908, 2008.
 41. Chareonthaitawee P , Christian TF , Hirose K , Gibbons RJ , Rumberger Ja . Relation of initial infarct size to extent of left ventricular remodeling in the year after acute myocardial infarction. J Am Coll Cardiol 25: 567‐573, 1995.
 42. Chaudhry PA , Mishima T , Sharov VG , Hawkins J , Alferness C , Paone G , Sabbah HN . Passive epicardial containment prevents ventricular remodeling in heart failure. Ann Thorac Surg 70: 1275‐1280, 2000.
 43. Chen JM , DeRose JJ , Slater JP , Spanier TB , Dewey TM , Catanese Ka , Flannery Ma , Oz MC . Improved survival rates support left ventricular assist device implantation early after myocardial infarction. J Am Coll Cardiol 33: 1903‐1908, 1999.
 44. Chen X , Nadiarynkh O , Plotnikov S , Campagnola PJ . Second harmonic generation microscopy for quantitative analysis of collagen fibrillar structure. Nat Protoc 7: 654‐669, 2012.
 45. Cheng JM , den Uil Ca , Hoeks SE , van der Ent M , Jewbali LSD , van Domburg RT , Serruys PW . Percutaneous left ventricular assist devices vs. intra‐aortic balloon pump counterpulsation for treatment of cardiogenic shock: A meta‐analysis of controlled trials. Eur Heart J 30: 2102‐2108, 2009.
 46. Clarke SA , Ghanta RK , Ailawadi G , Holmes JW . Cardiac Restraint and Support Following Myocardial Infarction. Studies in Mechanobiology, Tissue Engineering and Biomaterials: Cardiovascular and Cardiac Therapeutic Devices 15: 169‐206, 2013.
 47. Cleutjens JPM , Kandala JC , Guarda E , Guntaka RV , Weber KT . Regulation of collagen degradation in the rat myocardium after infarction. J Mol Cell Cardiol 1292: 1281‐1292, 1995.
 48. Connelly CM , McLaughlin RJ , Vogel WM , Apstein CS . Reversible and irreversible elongation of ischemic, infarcted, and healed myocardium in response to increases in preload and afterload. Circulation 84: 387‐399, 1991.
 49. Connelly CM , Vogel WM , Wiegner aW , Osmers EL , Bing OH , Kloner Ra , Dunn‐Lanchantin DM , Franzblau C , Apstein CS . Effects of reperfusion after coronary artery occlusion on post‐ infarction scar tissue. Circ Res 57: 562‐577, 1985.
 50. Covell JW , Ross J . Systolic and diastolic function (mechanics) of the intact heart. Handbook of Physiology 6: 741‐785, 2011.
 51. Creemers EEJM , Cleutjens JPM , Smits JFM , Daemen MJAP . Matrix metalloproteinase inhibition after myocardial infarction: A new approach to prevent heart failure? Circ Res 89: 201‐210, 2001.
 52. Creemers EEJM , Davis JN , Parkhurst AM , Leenders P , Dowdy KB , Hapke E , Hauet AM , Escobar PG , Cleutjens JPM , Smits JFM , Daemen MJAP , Zile MR , Spinale FG . Deficiency of TIMP‐1 exacerbates LV remodeling after myocardial infarction in mice. Am J Physiol Heart Circ Physiol 284: H364‐H371, 2003.
 53. Crozatier B , Ross J , Franklin D , Bloor CM , White FC , Tomoike H , McKown DP . Myocardial infarction in the baboon: Regional function and the collateral circulation. Am J Physiol 235: H413‐H421, 1978.
 54. Dai W , Wold LE , Dow JS , Kloner RA . Thickening of the infarcted wall by collagen injection improves left ventricular function in rats: A novel approach to preserve cardiac function after myocardial infarction. J Am Coll Cardiol 46: 714‐9, 2005.
 55. Dang ABC , Guccione JM , Zhang P , Wallace AW , Gorman RC , Gorman JH , Ratcliffe MB . Effect of ventricular size and patch stiffness in surgical anterior ventricular restoration: A finite element model study. Ann Thorac Surg 79: 185‐193, 2005.
 56. Daskalopoulos EP , Janssen BJA , Blankesteijn WM . Myofibroblasts in the infarct area: Concepts and challenges. Microsc Microanal 18: 35‐49, 2012.
 57. Dewald O , Ren G , Duerr GD , Zoerlein M , Klemm C , Gersch C , Tincey S , Michael LH , Entman ML , Frangogiannis NG . Of mice and dogs: Species‐specific differences in the inflammatory response following myocardial infarction. Am J Pathol 164: 665‐677, 2004.
 58. Dobaczewski M , Bujak M , Zymek P , Ren G , Entman ML , Frangogiannis NG . Extracellular matrix remodeling in canine and mouse myocardial infarcts. Cell Tissue Res 324: 475‐488, 2006.
 59. Dobaczewski M , Gonzalez‐Quesada C , Frangogiannis NG . The extracellular matrix as a modulator of the inflammatory and reparative response following myocardial infarction. J Mol Cell Cardiol 48: 504‐511, 2010.
 60. Dobner S , Bezuidenhout D , Govender P , Zilla P , Davies N . A synthetic non‐degradable polyethylene glycol hydrogel retards adverse post‐infarct left ventricular remodeling. J Card Fail 15: 629‐636, 2009.
 61. Doenst T , Faerber G , Grandinac S , Kuntze T , Menicanti L , Borger MA , Mohr FW . Surgical therapy of ventricular arrhythmias. Herzschrittmacherther Elektrophysiol 18: 62‐67, 2007.
 62. Doi M , Kusachi S , Murakami T , Ninomiya Y , Murakami M , Nakahama M , Takeda K , Komatsubara I , Naito I , Tsuji T . Time‐dependent changes of decorin in the infarct zone after experimentally induced myocardial infarction in rats: Comparison with biglycan. Pathol Res Pract 196: 23‐33, 2000.
 63. Dun W , Baba S , Yagi T , Boyden PA . Dynamic remodeling of K+ and Ca2+ currents in cells that survived in the epicardial border zone of canine healed infarcted heart. Am J Physiol Heart Circ Physiol 287: H1046‐H1054, 2004.
 64. Durrer JD , Lie KI , van Capelle FJ , Durrer D . Effect of sodium nitroprusside on mortality in acute myocardial infarction. N Engl J Med 306: 1121‐1128, 1982.
 65. Eaton LW , Weiss JL , Bulkley BH , Garrison JB , Weisfeldt ML . Regional cardiac dilatation after acute myocardial infarction: Recognition by two‐dimensional echocardiography. N Engl J Med 300: 57‐62, 1979.
 66. Erlebacher JA , Weiss JL , Weisfeldt ML , Bulkley BH . Early dilation of the infarcted segment in acute transmural myocardial infarction: Role of infarct expansion in acute left ventricular enlargement. J Am Coll Cardiol 4: 201‐208, 1984.
 67. Fielitz J , Philipp S , Herda LR , Schuch E , Pilz B , Schubert C , Günzler V , Willenbrock R , Regitz‐Zagrosek V . Inhibition of prolyl 4‐hydroxylase prevents left ventricular remodelling in rats with thoracic aortic banding. Eur J Heart Fail 9: 336‐342, 2007.
 68. Fieno DS , Hillenbrand HB , Rehwald WG , Harris KR , Decker RS , Parker MA , Klocke FJ , Kim RJ , Judd RM . Infarct resorption, compensatory hypertrophy, and differing patterns of ventricular remodeling following myocardial infarctions of varying size. J Am Coll Cardiol 43: 2124‐2131, 2004.
 69. Fishbein C , Maroko R , D M. The Histopathologic Evolution of Myocardial lnfarction. Chest 73: 843‐849, 1978.
 70. Fishbein MC , Maclean D , Maroko PR . Experimental myocardial infarction in the rat: Qualitative and quantitative changes during pathologic evolution. Am J Pathol 90: 57‐70, 1978.
 71. Fletcher PJ , Pfeffer JM , Pfeffer Ma , Braunwald E . Left ventricular diastolic pressure‐volume relations in rats with healed myocardial infarction. Effects on systolic function. Circ Res 49: 618‐626, 1981.
 72. Fomovsky GM , Clark SA , Parker KM , Ailawadi G , Holmes JW . Anisotropic reinforcement of acute anteroapical infarcts improves pump function. Circ Heart Fail 5: 515‐522, 2012.
 73. Fomovsky GM , Holmes JW . Evolution of scar structure, mechanics, and ventricular function after myocardial infarction in the rat. Am J Physiol Heart Circ Physiol 298: H221‐H228, 2010.
 74. Fomovsky GM , Macadangdang JR , Ailawadi G , Holmes JW . Model‐based design of mechanical therapies for myocardial infarction. J Cardiovasc Transl Res 4: 82‐91, 2011.
 75. Fomovsky GM , Rouillard AD , Holmes JW . Regional mechanics determine collagen fiber structure in healing myocardial infarcts. J Mol Cell Cardiol 52: 1083‐1090, 2012.
 76. Frangogiannis NG , Ren G , Dewald O , Zymek P , Haudek S , Koerting A , Winkelmann K , Michael LH , Lawler J , Entman ML . Critical role of endogenous thrombospondin‐1 in preventing expansion of healing myocardial infarcts. Circulation 111: 2935‐2942, 2005.
 77. Frangogiannis NG . The inflammatory response in myocardial injury, repair, and remodelling. Nat Rev Cardiol 11: 255‐265, 2014.
 78. Fujimoto KL , Tobita K , Merryman WD , Guan J , Momoi N , Stolz DB , Sacks MS , Keller BB , Wagner WR . An elastic, biodegradable cardiac patch induces contractile smooth muscle and improves cardiac remodeling and function in subacute myocardial infarction. J Am Coll Cardiol 49: 2292‐2300, 2007.
 79. Gao X‐M , Dilley RJ , Samuel CS , Percy E , Fullerton MJ , Dart AM , Du X‐J . Lower risk of postinfarct rupture in mouse heart overexpressing beta 2‐adrenergic receptors: Importance of collagen content. J Cardiovasc Pharmacol 40: 632‐640, 2002.
 80. Gao X‐M , White DA , Dart AM , Du X‐J . Post‐infarct cardiac rupture: Recent insights on pathogenesis and therapeutic interventions. Pharmacol Ther 134: 156‐179, 2012.
 81. Gardner PI , Ursell PC , Fenoglio JJ , Wit AL . Electrophysiologic and anatomic basis for fractionated electrograms recorded from healed myocardial infarcts. Circulation 72: 596‐611, 1985.
 82. Gaudesius G , Miragoli M , Thomas SP , Rohr S . Coupling of cardiac electrical activity over extended distances by fibroblasts of cardiac origin. Circ Res 93: 421‐428, 2003.
 83. Gaudron P , Eilles C , Kugler I , Ertl G . Progressive left ventricular dysfunction and remodeling after myocardial infarction. Potential mechanisms and early predictors. Circulation 87: 755‐763, 1993.
 84. Gay R , Wool S , Paquin M , Goldman S . Total vascular pressure‐volume relationship in conscious rats with chronic heart failure. Am J Physiol 251: H483‐H489, 1986.
 85. George I , Cheng Y , Yi G‐H , He K‐L , Li X , Oz MC , Holmes J , Wang J . Effect of passive cardiac containment on ventricular synchrony and cardiac function in awake dogs. Eur J Cardiothorac Surg 31: 55‐64, 2007.
 86. Gepstein L . Cell and gene therapy strategies for the treatment of postmyocardial infarction ventricular arrhythmias. Ann N Y Acad Sci 1188: 32‐38, 2010.
 87. Ghanta RK , Rangaraj A , Umakanthan R , Lee L , Laurence RG , Fox JA , Bolman RM , Cohn LH , Chen FY . Adjustable, physiological ventricular restraint improves left ventricular mechanics and reduces dilatation in an ovine model of chronic heart failure. Circulation 115: 1201‐1210, 2007.
 88. Gillam LD , Hogan RD , Foale RA , Franklin TD , Newell JB , Guyer DE , Weyman AE . A comparison of quantitative echocardiographic methods for delineating infarct‐induced abnormal wall motion. Circulation 70: 113‐122, 1984.
 89. Gillinov AM , Wierup PN , Blackstone EH , Bishay ES , Cosgrove DM , White J , Lytle BW , McCarthy PM . Is repair preferable to replacement for ischemic mitral regurgitation? J Thorac Cardiovasc Surg 122: 1125‐1141, 2001.
 90. Giraud M‐N , Flueckiger R , Cook S , Ayuni E , Siepe M , Carrel T , Tevaearai H . Long‐term evaluation of myoblast seeded patches implanted on infarcted rat hearts. Artif Organs 34: E184‐E192, 2010.
 91. Godier‐Furnémont AFG , Martens TP , Koeckert MS , Wan L , Parks J . Composite scaffold provides a cell delivery platform for cardiovascular repair. Proc Natl Acad Sci U S A 108: 7974‐7979, 2011.
 92. Godley RW , Wann LS , Rogers EW , Feigenbaum H , Weyman AE . Incomplete mitral leaflet closure in patients with papillary muscle dysfunction. Circulation 63: 565‐571, 1981.
 93. Goldsmith EC , Bradshaw AD , Spinale FG . Cellular mechanisms of tissue fibrosis. 2. Contributory pathways leading to myocardial fibrosis: Moving beyond collagen expression. Am J Physiol Cell Physiol 304: C393‐C402, 2013.
 94. Gorman JH , Gorman RC , Jackson BM , Hiramatsu Y , Gikakis N , Kelley ST , Sutton MG , Plappert T , Edmunds LH . Distortions of the mitral valve in acute ischemic mitral regurgitation. Ann Thorac Surg 64: 1026‐1031, 1997.
 95. Gorman JH , Gorman RC , Plappert T , Jackson BM , Hiramatsu Y , St John‐Sutton MG , Edmunds LH . Infarct size and location determine development of mitral regurgitation in the sheep model. J Thorac Cardiovasc Surg 115: 615‐622, 1998.
 96. Goshima K , Tonomura Y . Synchronized beating of embryonic mouse myocardial cells mediated by FL cells in monolayer culture. Exp Cell Res 56: 387‐392, 1969.
 97. Grigioni F , Detaint D , Avierinos J‐F , Scott C , Tajik J , Enriquez‐Sarano M . Contribution of ischemic mitral regurgitation to congestive heart failure after myocardial infarction. J Am Coll Cardiol 45: 260‐267, 2005.
 98. Guccione JM , Salahieh A , Moonly SM , Kortsmit J , Wallace AW , Ratcliffe MB . Myosplint decreases wall stress without depressing function in the failing heart: A finite element model study. Ann Thorac Surg 76: 1171‐1180; discussion 1180, 2003.
 99. Gupta KB , Ratcliffe MB , Fallert MA , Edmunds LH , Bogen DK . Changes in passive mechanical stiffness of myocardial tissue with aneurysm formation. Circulation 89: 2315‐2326, 1994.
 100. Guy TS , Moainie SL , Gorman JH , Jackson BM , Plappert T , Enomoto Y , St John‐Sutton MG , Edmunds LH , Gorman RC . Prevention of ischemic mitral regurgitation does not influence the outcome of remodeling after posterolateral myocardial infarction. J Am Coll Cardiol 43: 377‐383, 2004.
 101. Hammerman H , Kloner RA , Hale S , Schoen FJ , Braunwald E . Dose‐dependent effects of short‐term methylprednisolone on myocardial infarct extent, scar formation, and ventricular function. Circulation 68: 446‐452, 1983.
 102. Hammerman H , Kloner RA , Schoen FJ , Brown EJ , Hale S , Braunwald E . Indomethacin‐induced scar thinning after experimental myocardial infarction. Circulation 67: 1290‐1295, 1983.
 103. Hammerman H , Schoen FJ , Braunwald E , Kloner RA . Drug‐induced expansion of infarct: Morphologic and functional correlations. Circulation 69: 611‐617, 1984.
 104. Hammoud L , Lu X , Lei M , Feng Q . Deficiency in TIMP‐3 increases cardiac rupture and mortality post‐myocardial infarction via EGFR signaling: Beneficial effects of cetuximab. Basic Res Cardiol 106: 459‐471, 2011.
 105. Hands M , Lloyd B , Robinson J , Klerk N de , Thompson P . Prognostic significance of electrocardiographic site of infarction after correction for enzymatic size of infarction. Circulation 73: 885‐891, 1986.
 106. Haqqani HM , Marchlinski FE . Electrophysiologic substrate underlying postinfarction ventricular tachycardia: Characterization and role in catheter ablation. Heart Rhythm 6: S70‐S76, 2009.
 107. Hashima AR , Young AA , McCulloch AD , Waldman LK . Nonhomogeneous analysis of epicardial strain distributions during acute myocardial ischemia in the dog. J Biomech 26: 19‐35, 1993.
 108. Heger JJ , Wann LS , Weyman AE , Dillon JC , Feigenbaum H . Long‐term changes in mitral valve area after successful mitral commissurotomy. Circulation 59: 443‐448, 1979.
 109. Heymans S , Luttun A , Nuyens D , Theilmeier G , Creemers E , Moons L , Dyspersin GD , Cleutjens JP , Shipley M , Angellilo A , Levi M , Nübe O , Baker A , Keshet E , Lupu F , Herbert JM , Smits JF , Shapiro SD , Baes M , Borgers M , Collen D , Daemen MJ , Carmeliet P . Inhibition of plasminogen activators or matrix metalloproteinases prevents cardiac rupture but impairs therapeutic angiogenesis and causes cardiac failure. Nat Med 5: 1135‐1142, 1999.
 110. Hillenbrand HB , Sandstede J , Störk S , Ramsayer B , Hahn D , Ertl G , Koestler H , Bauer W , Ritter C . Remodeling of the infarct territory in the time course of infarct healing in humans. MAGMA 24: 277‐284, 2011.
 111. Hochman JS , Choo H . Limitation of myocardial infarct expansion by reperfusion independent of myocardial salvage. Circulation 75: 299‐306, 1987.
 112. Holmes JW , Borg TK , Covell JW . Structure and mechanics of healing myocardial infarcts. Annu Rev Biomed Eng 7: 223‐253, 2005.
 113. Holmes JW , Nuñez JA , Covell JW . Functional implications of myocardial scar structure. Am J Physiol 272: H2123‐H2130, 1997.
 114. Holmes JW , Yamashita H , Waldman LK , Covell JW . Scar remodeling and transmural deformation after infarction in the pig. Circulation 90: 411‐420, 1994.
 115. Hooks DA , Trew ML , Caldwell BJ , Sands GB , LeGrice IJ , Smaill BH . Laminar arrangement of ventricular myocytes influences electrical behavior of the heart. Circ Res 101: e103‐e112, 2007.
 116. Hutchins GM , Bulkley BH . Infarct expansion versus extension: Two different complications of acute myocardial infarction. Am J Cardiol 41: 1127‐1132, 1978.
 117. Hutter AM , DeSanctis RW , Flynn T , Yeatman LA . Nontransmural myocardial infarction: A comparison of hospital and late clinical course of patients with that of matched patients with transmural anterior and transmural inferior myocardial infarction. Am J Cardiol 48: 595‐602, 1981.
 118. Ifkovits JL , Tous E , Minakawa M , Morita M , Robb JD , Koomalsingh KJ , Gorman JH , Gorman RC , Burdick JA . Injectable hydrogel properties influence infarct expansion and extent of postinfarction left ventricular remodeling in an ovine model. Proc Natl Acad Sci U S A 107: 11507‐11512, 2010.
 119. Imanaka‐Yoshida K , Hiroe M , Nishikawa T , Ishiyama S , Shimojo T , Ohta Y , Sakakura T , Yoshida T . Tenascin‐C modulates adhesion of cardiomyocytes to extracellular matrix during tissue remodeling after myocardial infarction. Lab Invest 81: 1015‐1024, 2001.
 120. Janse MJ , Wit AL . Electrophysiological mechanisms of ventricular arrhythmias resulting from myocardial ischemia and infarction. Physiol Rev 69: 1049‐1169, 1989.
 121. Janz RF , Waldron RJ . Predicted effect of chronic apical aneurysms on the passive stiffness of the human left ventricle. Circ Res 42: 255‐263, 1978.
 122. Jugdutt BI , Amy RWM . Healing after myocardial infarction in the dog: Changes in infarct hydroxyproline and topography. J Am Coll Cardiol 7: 91‐102, 1986.
 123. Jugdutt BI , Joljart MJ , Khan MI . Rate of collagen deposition during healing and ventricular remodeling after myocardial infarction in rat and dog models. Circulation 94: 94‐101, 1996.
 124. Jugdutt BI , Schwarz‐Michorowski BL , Khan MI . Effect of long‐term captopril therapy on left ventricular remodeling and function during healing of canine myocardial infarction. J Am Coll Cardiol 19: 713‐21, 1992.
 125. Jugdutt BI , Warnica JW . Intravenous nitroglycerin therapy to limit myocardial infarct size, expansion, and complications. Effect of timing, dosage, and infarct location. Circulation 78: 906‐919, 1988.
 126. Jugdutt BI . Remodeling of the myocardium and potential targets in the collagen degradation and synthesis pathways. Curr Drug Targets Cardiovasc Haematol Disord 3: 1‐30, 2003.
 127. Jugdutt BI . Ventricular remodeling after infarction and the extracellular collagen matrix: When is enough enough? Circulation 108: 1395‐1403, 2003.
 128. Kapur NK , Paruchuri V , Urbano‐Morales JA , Mackey EE , Daly GH , Qiao X , Pandian N , Perides G , Karas RH . Mechanically unloading the left ventricle before coronary reperfusion reduces left ventricular wall stress and myocardial infarct size. Circulation 128: 328‐336, 2013.
 129. Kashem A , Hassan S , Crabbe DL , Melvin DB , Santamore WP , Chitwood WR . Left ventricular reshaping: Effects on the pressure‐volume relationship. J Thorac Cardiovasc Surg 125: 391‐399, 2003.
 130. Kashem A , Santamore WP , Hassan S , Crabbe DL , Margulies KB , Melvin DB . CardioClasp: A new passive device to re‐shape cardiac enlargement. ASAIO J (American Soc Artif Intern Organs) 48: 253‐259, 2002.
 131. Kashem A , Santamore WP , Hassan S , Melvin DB , Crabbe DL , Margulies KB , Goldman BI , Llort F , Krieger C , Lesniak J . CardioClasp changes left ventricular shape acutely in enlarged canine heart. J Cardiac Surg 18: S49‐S60, 2003.
 132. Kass DA , Maughan WL , Ciuffo A , Graves W , Healy B , Weisfeldt ML . Disproportionate epicardial dilation after transmural infarction of the canine left ventricle: Acute and chronic differences. J Am Coll Cardiol 11: 177‐185, 1988.
 133. Kellar RS , Shepherd BR , Larson DF , Naughton GK , Williams SK . Cardiac patch constructed from human fibroblasts attenuates reduction in cardiac function after acute infarct. Tissue Eng 11: 1678‐1687, 2006.
 134. Kelley ST , Malekan R , Gorman JHI , Jackson BM , Gorman C , Suzuki Y , Plappert T , Bogen DK , John MGS , Edmunds LH . Restraining infarct expansion preserves left ventricular geometry and function after acute anteroapical infarction. Circulation 99: 135‐142, 1999.
 135. Kerckhoffs RCP , McCulloch AD , Omens JH , Mulligan LJ . Effects of biventricular pacing and scar size in a computational model of the failing heart with left bundle branch block. Med Image Anal 13: 362‐369, 2009.
 136. Kidambi A , Mather AN , Swoboda P , Motwani M , Fairbairn TA , Greenwood JP , Plein S . Relationship between myocardial edema and regional myocardial function after reperfused acute myocardial infarction: An MR imaging study. Radiology 267: 701‐708, 2013.
 137. Kizana E , Ginn SL , Smyth CM , Boyd A , Thomas SP , Allen DG , Ross DL , Alexander IE . Fibroblasts modulate cardiomyocyte excitability: Implications for cardiac gene therapy. Gene Ther 13: 1611‐1615, 2006.
 138. Klocke R , Tian W , Kuhlmann MT , Nikol S . Surgical animal models of heart failure related to coronary heart disease. Cardiovasc Res 74: 29‐38, 2007.
 139. Knowlton AA , Connelly CM , Romo GM , Mamuya W , Apstein CS , Brecher P . Rapid expression of fibronectin in the rabbit heart after myocardial infarction with and without reperfusion. J Clin Invest 89: 1060‐1068, 1992.
 140. Koenig GC , Rowe RG , Day SM , Sabeh F , Atkinson JJ , Cooke KR , Weiss SJ . MT1‐MMP‐dependent remodeling of cardiac extracellular matrix structure and function following myocardial infarction. Am J Pathol 180: 1863‐1878, 2012.
 141. Kohl P , Camelliti P . Fibroblast‐myocyte connections in the heart. Heart Rhythm 9: 461‐464, 2012.
 142. Kohl P , Gourdie RG . Fibroblast‐myocyte electrotonic coupling: Does it occur in native cardiac tissue? J Mol Cell Cardiol 70: 37‐46, 2014.
 143. Kohl P , Noble D . Mechanosensitive connective tissue: Potential influence on heart rhythm. Cardiovasc Res 32: 62‐68, 1996.
 144. Komatsubara I , Murakami T , Kusachi S , Nakamura K , Hirohata S , Hayashi J , Takemoto S , Suezawa C , Ninomiya Y , Shiratori Y . Spatially and temporally different expression of osteonectin and osteopontin in the infarct zone of experimentally induced myocardial infarction in rats. Cardiovasc Pathol 12: 186‐94, 2003.
 145. Koomalsingh KJ , Witschey WRT , McGarvey JR , Shuto T , Kondo N , Xu C , Jackson BM , Gorman JH , Gorman RC , Pilla JJ . Optimized local infarct restraint improves left ventricular function and limits remodeling. Ann Thorac Surg 95: 155‐162, 2013.
 146. Kottkamp H , Vogt B , Hindricks G , Shenasa M , Haverkamp W , Borggrefe M , Breithardt G . Anisotropic conduction characteristics in ischemia‐reperfusion induced chronic myocardial infarction. Basic Res Cardiol 89: 177‐191, 1994.
 147. Kramer CM , Lima JA , Reichek N , Ferrari VA , Llaneras MR , Palmon LC , Yeh IT , Tallant B , Axel L . Regional differences in function within noninfarcted myocardium during left ventricular remodeling. Circulation 88: 1279‐1288, 1993.
 148. Kramer CM , Rogers WJ , Theobald TM , Power TP , Geskin G , Reichek N . Dissociation between changes in intramyocardial function and left ventricular volumes in the eight weeks after first anterior myocardial infarction. J Am Coll Cardiol 30: 1625‐1632, 1997.
 149. Kumanohoso T , Otsuji Y , Yoshifuku S , Matsukida K , Koriyama C , Kisanuki A , Minagoe S , Levine RA , Tei C . Mechanism of higher incidence of ischemic mitral regurgitation in patients with inferior myocardial infarction: Quantitative analysis of left ventricular and mitral valve geometry in 103 patients with prior myocardial infarction. J Thorac Cardiovasc Surg 125: 135‐143, 2003.
 150. Laeremans H , Hackeng TM , van Zandvoort MAMJ , Thijssen VLJL , Janssen BJA , Ottenheijm HCJ , Smits JFM , Blankesteijn WM . Blocking of frizzled signaling with a homologous peptide fragment of wnt3a/wnt5a reduces infarct expansion and prevents the development of heart failure after myocardial infarction. Circulation 124: 1626‐1635, 2011.
 151. Lamas GA , Mitchell GF , Flaker GC , Smith SCJ , Gersh BJ , Basta L , Moye L , Braunwald E , Pfeffer MA . Clinical Significance of mitral regurgitation after acute myocardial infarction. Circulation 96: 827‐833, 1997.
 152. Landa N , Miller L , Feinberg MS , Holbova R , Shachar M , Freeman I , Cohen S , Leor J . Effect of injectable alginate implant on cardiac remodeling and function after recent and old infarcts in rat. Circulation 117: 1388‐1396, 2008.
 153. Lee LS , Ghanta RK , Mokashi SA , Coelho‐Filho O , Kwong RY , Kwon M , Guan J , Liao R , Chen FY . Optimized ventricular restraint therapy: Adjustable restraint is superior to standard restraint in an ovine model of ischemic cardiomyopathy. J Thorac Cardiovasc Surg 145: 824‐831, 2012.
 154. Lehmann KG , Francis CK , Dodge HT . Mitral regurgitation in early myocardial infarction. Incidence, clinical detection, and prognostic implications. TIMI Study Group. Ann Intern Med 117: 10‐17, 1992.
 155. Leor J , Tuvia S , Guetta V , Manczur F , Castel D , Willenz U , Petneházy O , Landa N , Feinberg MS , Konen E , Goitein O , Tsur‐Gang O , Shaul M , Klapper L , Cohen S . Intracoronary injection of in situ forming alginate hydrogel reverses left ventricular remodeling after myocardial infarction in Swine. J Am Coll Cardiol 54: 1014‐1023, 2009.
 156. Lerman RH , Apstein CS , Kagan HM , Osmers EL , Chichester CO , Vogel WM , Connelly CM , Steffee WP . Myocardial healing and repair after experimental infarction in the rabbit. Circ Res 53: 378‐388, 1983.
 157. Lew WY , Chen ZY , Guth B , Covell JW . Mechanisms of augmented segment shortening in nonischemic areas during acute ischemia of the canine left ventricle. Circ Res 56: 351‐358, 1985.
 158. Liao S‐Y , Siu C‐W , Liu Y , Zhang Y , Chan W‐S , Wu EX , Wu Y , Nicholls JM , Li RA , Benser ME , Rosenberg SP , Park E , Lau C‐P , Tse H‐F . Attenuation of left ventricular adverse remodeling with epicardial patching after myocardial infarction. J Card Fail 16: 590‐598, 2010.
 159. Lindsey ML , Gannon J , Aikawa M , Schoen FJ , Rabkin E , Lopresti‐Morrow L , Crawford J , Black S , Libby P , Mitchell PG , Lee RT . Selective matrix metalloproteinase inhibition reduces left ventricular remodeling but does not inhibit angiogenesis after myocardial infarction. Circulation 105: 753‐758, 2002.
 160. Lindsey ML , Zamilpa R . Temporal and spatial expression of matrix metalloproteinases and tissue inhibitors of metalloproteinases following myocardial infarction. Cardiovasc Ther 30: 31‐41, 2012.
 161. Luke RA , Saffitz JE . Remodeling of ventricular conduction pathways in healed canine infarct border zones. J Clin Invest 87: 1594‐1602, 1991.
 162. Ma S , Yang D , Li D , Tang B , Sun M , Yang Y . Cardiac extracellular matrix tenascin‐C deposition during fibronectin degradation. Biochem Biophys Res Commun 409: 321‐327, 2011.
 163. Ma Y , de Castro Brás LE , Toba H , Iyer RP , Hall ME , Winniford MD , Lange RA , Tyagi SC , Lindsey ML . Myofibroblasts and the extracellular matrix network in post‐myocardial infarction cardiac remodeling. Pflugers Arch 466: 1113‐1127, 2014.
 164. Maglaveras N , de Bakker JM , van Capelle FJ , Pappas C , Janse MJ . Activation delay in healed myocardial infarction: A comparison between model and experiment. Am J Physiol Hear Circ Physiol 269: 0‐9, 1995.
 165. Maglaveras N , Van Capelle FJ , De Bakker JM . Wave propagation simulation in normal and infarcted myocardium: Computational and modelling issues. Med Inform (Lond) 23: 105‐118.
 166. Magovern JA , Teekell‐Taylor L , Mankad S , Dasika U , McGregor W , Biederman RWW , Yamrozik J , Trumble DR . Effect of a flexible ventricular restraint device on cardiac remodeling after acute myocardial infarction. ASAIO J (American Soc Artif Intern Organs) 52: 196‐200, 2006.
 167. Mannisi JA , Weisman HF , Bush DE , Dudeck P , Healy B . Steroid administration after myocardial infarction promotes early infarct expansion. A study in the rat. J Clin Invest 79: 1431‐1439, 1987.
 168. Marijianowski MM , Teeling P , Becker AE . Remodeling after myocardial infarction in humans is not associated with interstitial fibrosis of noninfarcted myocardium. J Am Coll Cardiol 30: 76‐82, 1997.
 169. Marmor A , Geltman EM , Schechtman K , Sobel BE , Roberts R . Recurrent myocardial infarction: Clinical predictors and prognostic implications. Circulation 66: 415‐421, 1982.
 170. Marmor A , Sobel BE , Roberts R . Factors presaging early recurrent myocardial infarction (“Extension”). Am J Cardiol 48: 603‐610, 1981.
 171. Mathey D , Biefield W , Hanrath P , Effert S . Attempt to quantitate relation between cardiac function and infarct size in acute myocardial infarction. Br Heart J 36: 271‐279, 1974.
 172. Matsui Y , Morimoto J , Uede T . Role of matricellular proteins in cardiac tissue remodeling after myocardial infarction. World J Biol Chem 1: 69‐80, 2010.
 173. May‐Newman K , Omens JH , Pavelec RS , McCulloch AD . Three‐dimensional transmural mechanical interaction between the coronary vasculature and passive myocardium in the dog. Circ Res 74: 1166‐1178, 1994.
 174. McCarthy PM , Takagaki M , Ochiai Y , Young JB , Tabata T , Shiota T , Qin JX , Thomas JD , Mortier TJ , Schroeder RF , Schweich CJ , Fukamachi K . Device‐based change in left ventricular shape: A new concept for the treatment of dilated cardiomyopathy. J Thorac Cardiovasc Surg 122: 482‐490, 2001.
 175. McCormick RJ , Musch TI , Bergman BC , Thomas DP . Regional differences in LV collagen accumulation and mature cross‐linking after myocardial infarction in rats. Am J Physiol 266: H354‐H359, 1994.
 176. McDowell KS , Arevalo HJ , Maleckar MM , Trayanova NA . Susceptibility to arrhythmia in the infarcted heart depends on myofibroblast density. Biophys J 101: 1307‐1315, 2011.
 177. McKay RG , Pfeffer MA , Pasternak RC , Markis JE , Come PC , Nakao S , Alderman JD , Ferguson JJ , Safian RD , Grossman W . Left ventricular remodeling after myocardial infarction: A corollary to infarct expansion. Circulation 74: 693‐702, 1986.
 178. Mehta PM , Alker KJ , Kloner RA . Functional infarct expansion, left ventricular dilation and isovolumic relaxation time after coronary occlusion: A two‐dimensional echocardiographic study. J Am Coll Cardiol 11: 630‐636, 1988.
 179. Miragoli M , Gaudesius G , Rohr S . Electrotonic modulation of cardiac impulse conduction by myofibroblasts. Circ Res 98: 801‐810, 2006.
 180. Moainie SL , Guy TS , Gorman JHI , Plappert T , Jackson BM , St John‐Sutton MG , Edmunds LH , Gorman RC . Infarct restraint attenuates remodeling and reduces chronic ischemic mitral regurgitation after postero‐lateral infarction. Ann Thorac Surg 74: 444‐449, 2002.
 181. Moore CA , Nygaard TW , Kaiser DL , Cooper AA , Gibson RS . Postinfarction ventricular septal rupture: The importance of location of infarction and right ventricular function in determining survival. Circulation 74: 45‐55, 1986.
 182. Morishita N , Kusachi S , Yamasaki S , Kondo J , Tsuji T . Sequential changes in laminin and type IV collagen in the infarct zone‐immunohistochemical study in rat myocardial infarction. Jpn Circ J 60: 108‐114, 1996.
 183. Morita M , Eckert CE , Matsuzaki K , Noma M , Ryan LP , Burdick JA , Jackson BM , Gorman JH , Sacks MS , Gorman RC . Modification of infarct material properties limits adverse ventricular remodeling. Ann Thorac Surg 92: 617‐624, 2011.
 184. Mukherjee D , Feldman MS , Helfant RH . Nitroprusside therapy. Treatment of hypertensive patients with recurrent resting chest pain, ST‐segment elevation, and ventricular arrhythmias. JAMA 235: 2406‐2409, 1976.
 185. Mukherjee D , Sen S . Alteration of collagen phenotypes in ischemic cardiomyopathy. J Clin Invest 88: 1141‐1146, 1991.
 186. Mukherjee R , Zavadzkas JA , Saunders SM , McLean JE , Jeffords LB , Beck C , Stroud RE , Leone AM , Koval CN , Rivers WT , Basu S , Sheehy A , Michal G , Spinale FG . Targeted myocardial microinjections of a biocomposite material reduces infarct expansion in pigs. Ann Thorac Surg 86: 1268‐1276, 2008.
 187. Naeim F , De La Maza LM , Robbins SL . Cardiac rupture during myocardial infarction: A review of 44 cases. Circulation 45: 1231‐1239, 1972.
 188. Nahrendorf M , Wiesmann F , Hiller KH , Hu K , Waller C , Ruff J , Lanz TE , Neubauer S , Haase A , Ertl G , Bauer WR . Serial cine‐magnetic resonance imaging of left ventricular remodeling after myocardial infarction in rats. J Magn Reson Imaging 14: 547‐555, 2001.
 189. Naugle JE , Olson ER , Zhang X , Mase SE , Pilati CF , Maron MB , Folkesson HG , Horne WI , Doane KJ , Meszaros JG . Type VI collagen induces cardiac myofibroblast differentiation: Implications for postinfarction remodeling. Am J Physiol Heart Circ Physiol 290: H323‐H330, 2006.
 190. Nicod P , Gilpin E , Dittrich H , Polikar R , Hjalmarson A , Blacky AR , Henning H , Ross J . Short‐ and long‐term clinical outcome after Q wave and non‐Q wave myocardial infarction in a large patient population. Circulation 79: 528‐536, 1989.
 191. Nieminen M , Heikkilä J . Echoventriculography in acute myocardial infarction. III. Clinical correlations and implication of the noninfarcted myocardium. Am J Cardiol 38: 1‐8, 1976.
 192. Nishioka T , Onishi K , Shimojo N , Nagano Y , Matsusaka H , Ikeuchi M , Ide T , Tsutsui H , Hiroe M , Yoshida T , Imanaka‐Yoshida K . Tenascin‐C may aggravate left ventricular remodeling and function after myocardial infarction in mice. Am J Physiol Heart Circ Physiol 298: H1072‐H1078, 2010.
 193. Nwogu JI , Geenen D , Bean M , Brenner MC , Huang X , Buttrick PM . Inhibition of collagen synthesis with prolyl 4‐hydroxylase inhibitor improves left ventricular function and alters the pattern of left ventricular dilatation after myocardial infarction. Circulation 104: 2216‐2221, 2001.
 194. Oka T , Xu J , Kaiser RA , Melendez J , Hambleton M , Sargent MA , Lorts A , Brunskill EW , Dorn GW , Conway SJ , Aronow BJ , Robbins J , Molkentin JD . Genetic manipulation of periostin expression reveals a role in cardiac hypertrophy and ventricular remodeling. Circ Res 101: 313‐321, 2007.
 195. Olivetti G , Capasso JM , Sonnenblick EH , Anversa P . Side‐to‐side slippage of myocytes participates in ventricular wall remodeling acutely after myocardial infarction in rats. Circ Res 67: 23‐34, 1990.
 196. Omens JH , Miller TR , Covell JW . Relationship between passive tissue strain and collagen uncoiling during healing of infarcted myocardium. Cardiovasc Res 33: 351‐358, 1997.
 197. Orn S , Manhenke C , Anand IS , Squire I , Nagel E , Edvardsen T , Dickstein K . Effect of left ventricular scar size, location, and transmurality on left ventricular remodeling with healed myocardial infarction. Am J Cardiol 99: 1109‐1114, 2007.
 198. Oz MC , Konertz WF , Kleber FX , Mohr FW , Gummert JF , Ostermeyer J , Lass M , Raman J , Acker MA , Smedira N . Global surgical experience with the Acorn cardiac support device. J Thorac Cardiovasc Surg 126: 983‐991, 2003.
 199. Page DL , Caulfield JB , Kastor JA , DeSanctis RW , Sanders CA . Myocardial changes associated with cardiogenic shock. N Engl J Med 285: 133‐137, 1971.
 200. Palaniyappan A , Uwiera RRE , Idikio H , Jugdutt BI . Comparison of vasopeptidase inhibitor omapatrilat and angiotensin receptor blocker candesartan on extracellular matrix, myeloperoxidase, cytokines, and ventricular remodeling during healing after reperfused myocardial infarction. Mol Cell Biochem 321: 9‐22, 2009.
 201. Parmley WW , Chuck L , Kivowitz C , Matloff JM , Swan HJ . In vitro length‐tension relations of human ventricular aneurysms. Relation of stiffness to mechanical disadvantage. Am J Cardiol 32: 889‐894, 1973.
 202. Pellizzon GG , Grines CL , Cox DA , Stuckey T , Tcheng JE , Garcia E , Guagliumi G , Turco M , Lansky AJ , Griffin JJ , Cohen DJ , Aymong E , Mehran R , O'Neill WW , Stone GW . Importance of mitral regurgitation inpatients undergoing percutaneous coronary intervention for acute myocardial infarction: The controlled abciximab and device investigation to lower late angioplasty complications (CADILLAC) trial. J Am Coll Cardiol 43: 1368‐1374, 2004.
 203. Peterson JT , Li H , Dillon L , Bryant JW . Evolution of matrix metalloprotease and tissue inhibitor expression during heart failure progression in the infarcted rat. Cardiovasc Res 46: 307‐315, 2000.
 204. Pfeffer J , Pfeffer M , Fletcher P , Braunwald E . Progressive ventricular remodeling in rat with myocardial infarction. Am J Physiol Heart Circ Physiol 260: H1406‐H1414, 1991.
 205. Pfeffer MA , Braunwald E . Ventricular remodeling after myocardial infarction. Experimental observations and clinical implications. Circulation 81: 1161‐1172, 1990.
 206. Pfeffer M , Pfeffer J , Fishbein M , Fletcher P , Spadaro J , Kloner R , Braunwald E . Myocardial infarct size and ventricular function in rats. Circ Res 44: 503‐512, 1979.
 207. Pfeffer MA , Pfeffer JM , Steinberg C , Finn P . Survival after an experimental myocardial infarction: Beneficial effects of long‐term therapy with captopril. Circulation 72: 406‐412, 1985.
 208. Piao H , Kwon J‐S , Piao S , Sohn J‐H , Lee Y‐S , Bae J‐W , Hwang K‐K , Kim D‐W , Jeon O , Kim B‐S , Park Y‐B , Cho M‐C . Effects of cardiac patches engineered with bone marrow‐derived mononuclear cells and PGCL scaffolds in a rat myocardial infarction model. Biomaterials 28: 641‐649, 2007.
 209. Pilla JJ , Blom AS , Gorman JHI , Brockman DJ , Affuso J , Parish LM , Sakamoto H , Jackson BM , Acker MA , Gorman RC . Early postinfarction ventricular restraint improves borderzone wall thickening dynamics during remodeling. Ann Thorac Surg 80: 2257‐2562, 2005.
 210. Pirolo JS , Hutchins GM , Moore GW . Infarct expansion: Pathologic analysis of 204 patients with a single myocardial infarct. J Am Coll Cardiol 7: 349‐354, 1986.
 211. Pirzada FA , Ekong EA , Vokonas PS , Apstein CS , Hood WB . Experimental myocardial infarction. XIII. Sequential changes in left ventricular pressure‐length relationships in the acute phase. Circulation 53: 970‐975, 1976.
 212. Power JM , Raman J , Dornom A , Farish SJ , Burrell LM , Tonkin AM , Buxton B , Alferness CA . Passive ventricular constraint amends the course of heart failure: A study in an ovine model of dilated cardiomyopathy. Cardiovasc Res 44: 549‐555, 1999.
 213. Quinn TA , Camelliti P , Siedlecka U , Poggioli T , Loew LM , Knopfel T , Kohl P . Abstract 11749: Cell‐specific expression of voltage‐sensitive protein confirms cardiac myocyte to non‐myocyte electrotonic coupling in healed murine infarct border tissue. Circulation 130: A11749, 2014.
 214. Quinn TA , Kohl P . Combining wet and dry research: Experience with model development for cardiac mechano‐electric structure‐function studies. Cardiovasc Res 97: 601‐611, 2013.
 215. Quinn TA . The importance of non‐uniformities in mechano‐electric coupling for ventricular arrhythmias. J Interv Card Electrophysiol 39: 25‐35, 2014.
 216. Ramani R , Nilles K , Gibson G , Burkhead B , Mathier M , McNamara D , McTiernan CF . Tissue inhibitor of metalloproteinase‐2 gene delivery ameliorates postinfarction cardiac remodeling. Clin Transl Sci 4: 24‐31, 2011.
 217. Rane AA , Christman KL . Biomaterials for the treatment of myocardial infarction: A 5‐year update. J Am Coll Cardiol 58: 2615‐2629, 2011.
 218. Rane AA , Chuang JS , Shah A , Hu DP , Dalton ND , Gu Y , Peterson KL , Omens JH , Christman KL . Increased infarct wall thickness by a bio‐inert material is insufficient to prevent negative left ventricular remodeling after myocardial infarction. PLoS One 6: e21571, 2011.
 219. Raya TE , Gay RG , Aguirre M , Goldman S . Importance of venodilatation in prevention of left ventricular dilatation after chronic large myocardial infarction in rats: A comparison of captopril and hydralazine. Circ Res 64: 330‐337, 1989.
 220. Raya TE , Gay RG , Lancaster L , Aguirre M , Moffett C , Goldman S . Serial changes in left ventricular relaxation and chamber stiffness after large myocardial infarction in rats. Circulation 77: 1424‐1431, 1988.
 221. Reimer KA , Jennings RB . The changing anatomic reference base of evolving myocardial infarction. Underestimation of myocardial collateral blood flow and overestimation of experimental anatomic infarct size due to tissue edema, hemorrhage and acute inflammation. Circulation 60: 866‐876, 1979.
 222. Reimer KA , Vander Heide RS , Richard VJ . Reperfusion in acute myocardial infarction: Effect of timing and modulating factors in experimental models. Am J Cardiol 72: 13G‐21G, 1993.
 223. Richard V , Murry CE , Reimer KA . Healing of myocardial infarcts in dogs. Effects of late reperfusion. Circulation 92: 1891‐1901, 1995.
 224. Rigo P , Murray M , Taylor DR , Weisfeldt ML , Strauss HW , Pitt B . Hemodynamic and prognostic findings in patients with transmural and nontransmural infarction. Circulation 51: 1064‐1070, 1975.
 225. Roberts CS , Maclean D , Maroko P , Kloner RA . Early and late remodeling of the left ventricle after acute myocardial infarction. Am J Cardiol 54: 407‐410, 1984.
 226. Roberts R , DeMello V , Sobel BE . Deleterious effects of methylprednisolone in patients with myocardial infarction. Circulation 53: I204‐I206, 1976.
 227. Roes SD , Kelle S , Kaandorp TAM , Kokocinski T , Poldermans D , Lamb HJ , Boersma E , van der Wall EE , Fleck E , de Roos A , Nagel E , Bax JJ . Comparison of myocardial infarct size assessed with contrast‐enhanced magnetic resonance imaging and left ventricular function and volumes to predict mortality in patients with healed myocardial infarction. Am J Cardiol 100: 930‐936, 2007.
 228. Rogers WJ , Kramer CM , Geskin G , Hu YL , Theobald TM , Vido DA , Petruolo S , Reichek N . Early contrast‐enhanced MRI predicts late functional recovery after reperfused myocardial infarction. Circulation 99: 744‐750, 1999.
 229. Rohr S . Arrhythmogenic implications of fibroblast‐myocyte interactions. Circ Arrhythm Electrophysiol 5: 442‐452, 2012.
 230. Rouillard AD , Holmes JW . Mechanical regulation of fibroblast migration and collagen remodelling in healing myocardial infarcts. J Physiol 590: 4585‐4602, 2012.
 231. Rouillard AD , Holmes JW . Coupled agent‐based and finite‐element models for predicting scar structure following myocardial infarction. Prog Biophys Mol Biol 115: 235‐243, 2014.
 232. Rutherford SL , Trew ML , Sands GB , LeGrice IJ , Smaill BH . High‐resolution 3‐dimensional reconstruction of the infarct border zone: Impact of structural remodeling on electrical activation. Circ Res 111: 301‐311, 2012.
 233. Ryan LP , Matsuzaki K , Noma M , Jackson BM , Eperjesi TJ , Plappert TJ , St John‐Sutton MG , Gorman JH , Gorman RC . Dermal filler injection: A novel approach for limiting infarct expansion. Ann Thorac Surg 87: 148‐155, 2009.
 234. Sagawa K . Baroreflex control of systemic arterial pressure and vascular bed. Handbook of Physiology 8: 453‐496, 2011.
 235. Sato S , Ashraf M , Millard RW , Fujiwara H , Schwartz A . Connective tissue changes in early ischemia of porcine myocardium: An ultrastructural study. J Mol Cell Cardiol 15: 261‐275, 1983.
 236. Savage RM , Guth B , White FC , Hagan AD , Bloor CM . Correlation of regional myocardial blood flow and function with myocardial infarct size during acute myocardial ischemia in the conscious pig. Circulation 64: 699‐707, 1981.
 237. Schellings MWM , Vanhoutte D , Swinnen M , Cleutjens JP , Debets J , van Leeuwen REW , d'Hooge J , Van de Werf F , Carmeliet P , Pinto YM , Sage EH , Heymans S . Absence of SPARC results in increased cardiac rupture and dysfunction after acute myocardial infarction. J Exp Med 206: 113‐123, 2009.
 238. Schorb W , Ertl G . Angiotensin II Type 1 receptor induced signal‐transduction pathways as new targets for pharmacological treatment of the renin‐angiotensin system. Basic Res Cardiol 91: 91‐96, 1996.
 239. Schuster EH , Bulkley BH . Expansion of transmural myocardial infarction: A pathophysiologic factor in cardiac rupture. Circulation 60: 1532‐1538, 1979.
 240. Severs NJ , Bruce AF , Dupont E , Rothery S . Remodelling of gap junctions and connexin expression in diseased myocardium. Cardiovasc Res 80: 9‐19, 2008.
 241. Severs NJ , Coppen SR , Dupont E , Yeh H‐I , Ko Y‐S , Matsushita T . Gap junction alterations in human cardiac disease. Cardiovasc Res 62: 368‐377, 2004.
 242. Simpson D , Liu H , Fan T‐HM , Nerem R , Dudley SC . A tissue engineering approach to progenitor cell delivery results in significant cell engraftment and improved myocardial remodeling. Stem Cells 25: 2350‐2357, 2007.
 243. Smaill BH , Zhao J , Trew ML . Three‐dimensional impulse propagation in myocardium: Arrhythmogenic mechanisms at the tissue level. Circ Res 112: 834‐848, 2013.
 244. Spotnitz HM . Macro design, structure, and mechanics of the left ventricle. J Thorac Cardiovasc Surg 119: 1053‐1077, 2000.
 245. Stockbridge LL , French AS . Stretch‐activated cation channels in human fibroblasts. Biophys J 54: 187‐190, 1988.
 246. Stone PH , Raabe DS , Jaffe AS . Prognostic significance of location and type of myocardial infarction: Independent adverse outcome associated with anterior location. J Am Coll Cardiol 11: 453‐463, 1988.
 247. Strungs EG , Ongstad EL , Quinn MPO , Palatinus JA , Jourdan LJ , Gourdie RG . Cryoinjury Models of the Adult and Neonatal Mouse Heart for Studies of Scarring and Regeneration. Methods in Molecular Biology 1037: 343‐353, 2013.
 248. Suga H , Sagawa K , Shoukas AA . Load independence of the instantaneous pressure‐volume ratio of the canine left ventricle and effects of epinephrine and heart rate on the ratio. Circ Res 32: 314‐322, 1973.
 249. Sun Y , Weber KT . Infarct scar: A dynamic tissue. Cardiovasc Res 46: 250‐256, 2000.
 250. Sun Y , Zhang JQ , Zhang J , Lamparter S . Cardiac remodeling by fibrous tissue after infarction in rats. J Lab Clin Med 135: 316‐323, 2000.
 251. Sunagawa K , Maughan WL , Sagawa K . Effect of regional ischemia on the left ventricular end‐systolic pressure‐volume relationship of isolated canine hearts. Circ Res 52: 170‐178, 1983.
 252. Swift J , Ivanovska IL , Buxboim A , Harada T , Dingal PCDP , Pinter J , Pajerowski JD , Spinler KR , Shin J‐W , Tewari M , Rehfeldt F , Speicher DW , Discher DE . Nuclear lamin‐A scales with tissue stiffness and enhances matrix‐directed differentiation. Science 341: 1240104, 2013.
 253. Szklo M , Goldberg R , Kennedy HL , Tonascia JA . Survival of patients with nontransmural myocardial infarction: A population‐based study. Am J Cardiol 42: 648‐652, 1978.
 254. Takahashi S , Barry AC , Factor SM . Collagen degradation in ischaemic rat hearts. Biochem J 265: 233‐241, 1990.
 255. Tennant R , Wiggers CJ . The effect of coronary occlusion on myocardial contraction. Am J Physiol 112: 351‐361, 1935.
 256. Thanavaro S , Kleiger RE , Province MA , Hubert JW , Miller JP , Krone RJ , Oliver GC . Effect of infarct location on the in‐hospital prognosis of patients with first transmural myocardial infarction. Circulation 66: 742‐747, 1982.
 257. Theroux P , Franklin D , Ross J , Kemper WS . Regional myocardial function during acute coronary artery occlusion and its modification by pharmacologic agents in the dog. Circ Res 35: 896‐908, 1974.
 258. Theroux P , Ross J , Franklin D , Covell JW , Bloor CM , Sasayama S . Regional myocardial function and dimensions early and late after myocardial infarction in the unanesthetized dog. Circ Res 40: 158‐165, 1977.
 259. Theroux P , Ross J , Franklin D , Kemper WS , Sasayama S . Coronary arterial reperfusion. III. Early and late effects on regional myocardial function and dimensions in conscious dogs. Am J Cardiol 38: 599‐606, 1976.
 260. Thiele H , Smalling RW , Schuler GC . Percutaneous left ventricular assist devices in acute myocardial infarction complicated by cardiogenic shock. Eur Heart J 28: 2057‐2063, 2007.
 261. Thomas JA , Marks BH . Plasma norepinephrine in congestive heart failure. Am J Cardiol 41: 233‐243, 1978.
 262. Thompson SA , Copeland CR , Reich DH , Tung L . Mechanical coupling between myofibroblasts and cardiomyocytes slows electric conduction in fibrotic cell monolayers. Circulation 123: 2083‐2093, 2011.
 263. Trueblood NA , Xie Z , Communal C , Sam F , Ngoy S , Liaw L , Jenkins AW , Wang J , Sawyer DB , Bing OH , Apstein CS , Colucci WS , Singh K . Exaggerated left ventricular dilation and reduced collagen deposition after myocardial infarction in mice lacking osteopontin. Circ Res 88: 1080‐1087, 2001.
 264. Tyberg JV , Forrester JS , Wyatt HL , Goldner SJ , Parmley WW , Swan HJC . An analysis of segmental ischemic dysfunction utilizing the pressure‐length loop. Circulation 49: 748‐754, 1974.
 265. Ursell PC , Gardner PI , Albala A , Fenoglio JJ , Wit AL . Structural and electrophysiological changes in the epicardial border zone of canine myocardial infarcts during infarct healing. Circ Res 56: 436‐451, 1985.
 266. Vandervelde S , Amerongen MJ , Van, Tio RA , Petersen AH , Luyn MJA Van , Harmsen MC . Increased inflammatory response and neovascularization in reperfused vs. nonreperfused murine myocardial infarction. Cardiovasc Pathol 15: 83‐90, 2006.
 267. Vanhoutte D , Schellings M , Pinto Y , Heymans S . Relevance of matrix metalloproteinases and their inhibitors after myocardial infarction: A temporal and spatial window. Cardiovasc Res 69: 604‐613, 2006.
 268. Vasquez C , Mohandas P , Louie KL , Benamer N , Bapat AC , Morley GE . Enhanced fibroblast‐myocyte interactions in response to cardiac injury. Circ Res 107: 1011‐1020, 2010.
 269. Vigmond E , Vadakkumpadan F , Gurev V , Arevalo H , Deo M , Plank G , Trayanova N . Towards predictive modelling of the electrophysiology of the heart. Exp Physiol 94: 563‐577, 2009.
 270. Villarreal FJ , Griffin M , Omens J , Dillmann W , Nguyen J , Covell J . Early short‐term treatment with doxycycline modulates postinfarction left ventricular remodeling. Circulation 108: 1487‐1492, 2003.
 271. Villarreal FJ , Lew WY , Waldman LK , Covell JW . Transmural myocardial deformation in the ischemic canine left ventricle. Circ Res 68: 368‐381, 1991.
 272. Vivaldi MT , Eyre DR , Kloner RA , Schoen FJ . Effects of methylprednisolone on collagen biosynthesis in healing acute myocardial infarction. Am J Cardiol 60: 424‐425, 1987.
 273. Vokonas PS , Pirzada F , Hood WB . Experimental myocardial infarction: XII. Dynamic changes in segmental mechanical behavior of infarcted and non‐infarcted myocardium. Am J Cardiol 37: 853‐859, 1976.
 274. Walker NL , Burton FL , Kettlewell S , Smith GL , Cobbe SM . Mapping of epicardial activation in a rabbit model of chronic myocardial infarction. J Cardiovasc Electrophysiol 18: 862‐868, 2007.
 275. Wall ST , Walker JC , Healy KE , Ratcliffe MB , Guccione JM . Theoretical impact of the injection of material into the myocardium: A finite element model simulation. Circulation 114: 2627‐2635, 2006.
 276. Watanabe R , Ogawa M , Suzuki J‐I , Hirata Y , Nagai R , Isobe M . A comparison between imidapril and ramipril on attenuation of ventricular remodeling after myocardial infarction. J Cardiovasc Pharmacol 59: 323‐330, 2012.
 277. Wei S , Chow LT , Sanderson JE . Effect of carvedilol in comparison with metoprolol on myocardial collagen postinfarction. J Am Coll Cardiol 36: 276‐281, 2000.
 278. Wei S , Chow LT , Shum IO , Qin L , Sanderson JE . Left and right ventricular collagen type I/III ratios and remodeling post‐myocardial infarction. J Card Fail 5: 117‐126, 1999.
 279. Weisman HF , Bush DE , Mannisi JA , Bulkley BH . Global cardiac remodeling after acute myocardial infarction: A study in the rat model. J Am Coll Cardiol 5: 1355‐1362, 1985.
 280. Weisman HF , Bush DE , Mannisi JA , Weisfeldt ML , Healy B . Cellular mechanisms of myocardial infarct expansion. Circulation 78: 186‐201, 1988.
 281. Wenk JF , Eslami P , Zhang Z , Xu C , Kuhl E , Gorman JH , Robb JD , Ratcliffe MB , Gorman RC , Guccione JM . A novel method for quantifying the in‐vivo mechanical effect of material injected into a myocardial infarction. Ann Thorac Surg 92: 935‐941, 2011.
 282. Wenk JF , Wall ST , Peterson RC , Helgerson SL , Sabbah HN , Burger M , Stander N , Ratcliffe MB , Guccione JM . A method for automatically optimizing medical devices for treating heart failure: Designing polymeric injection patterns. J Biomech Eng 131: 121011, 2009.
 283. Westermann D , Mersmann J , Melchior A , Freudenberger T , Petrik C , Schaefer L , Lüllmann‐Rauch R , Lettau O , Jacoby C , Schrader J , Brand‐Herrmann S‐M , Young MF , Schultheiss HP , Levkau B , Baba HA , Unger T , Zacharowski K , Tschöpe C , Fischer JW . Biglycan is required for adaptive remodeling after myocardial infarction. Circulation 117: 1269‐1276, 2008.
 284. White HD , Norris RM , Brown MA , Brandt PW , Whitlock RM , Wild CJ . Left ventricular end‐systolic volume as the major determinant of survival after recovery from myocardial infarction. Circulation 76: 44‐51, 1987.
 285. White M , Rouleau JL , Hall C , Arnold M , Harel F , Sirois P , Greaves S , Solomon S , Ajani U , Glynn R , Hennekens C , Pfeffer M . Changes in vasoconstrictive hormones, natriuretic peptides, and left ventricular remodeling soon after anterior myocardial infarction. Am Heart J 142: 1056‐1064, 2001.
 286. Whittaker P , Boughner DR , Kloner RA . Role of collagen in acute myocardial infarct expansion. Circulation 84: 2123‐2134, 1991.
 287. Whittaker P , Kloner RA , Boughner DR , Pickering JG . Quantitative assessment of myocardial collagen with picrosirius red staining and circularly polarized light. Basic Res Cardiol 89: 397‐410, 1994.
 288. Whittaker P . Collagen organization in wound healing after myocardial injury. Basic Res Cardiol 93(Suppl 3): 23‐25, 1998.
 289. Wu KC , Zerhouni Ea , Judd RM , Lugo‐Olivieri CH , Barouch La , Schulman SP , Blumenthal RS , Lima JAC . Prognostic significance of microvascular obstruction by magnetic resonance imaging in patients with acute myocardial infarction. Circulation 97: 765‐772, 1998.
 290. Yagishita D , Ajijola OA , Vaseghi M , Nsair A , Zhou W , Yamakawa K , Tung R , Mahajan A , Shivkumar K . Electrical homogenization of ventricular scar by application of collagenase: A novel strategy for arrhythmia therapy. Circ Arrhythmia Electrophysiol 6: 776‐783, 2013.
 291. Yamamoto K , Kusachi S , Ninomiya Y , Murakami M , Doi M , Takeda K , Shinji T , Higashi T , Koide N , Tsuji T . Increase in the expression of biglycan mRNA expression Co‐localized closely with that of type I collagen mRNA in the infarct zone after experimentally‐induced myocardial infarction in rats. J Mol Cell Cardiol 30: 1749‐1756, 1998.
 292. Yamanishi A , Kusachi S , Nakahama M , Ninomiya Y , Watanabe T , Kumashiro H , Nunoyama H , Kondo J , Naito I , Tsuji T . Sequential changes in the localization of the type IV collagen alpha chain in the infarct zone: Immunohistochemical study of experimental myocardial infarction in the rat. Pathol Res Pract 194: 413‐422, 1998.
 293. Yang F , Liu Y , Yang X , Xu J , Kapke A , Carretero OA . Myocardial infarction and cardiac remodelling in mice. Exp Physiol 87: 547‐ 555.
 294. Yoshida K , Gould KL . Quantitative relation of myocardial infarct size and myocardial viability by positron emission tomography to left ventricular ejection fraction and 3‐year mortality with and without revascularization. J Am Coll Cardiol 22: 984‐997, 1993.
 295. Young AA , French BA , Yang Z , Cowan BR , Gilson WD , Berr SS , Kramer CM , Epstein FH . Reperfused myocardial infarction in mice: 3D mapping of late gadolinium enhancement and strain. J Cardiovasc Magn Reson 8: 685‐692, 2006.
 296. Yue Z , Zhang Y , Xie J , Jiang J , Yue L . Transient receptor potential (TRP) channels and cardiac fibrosis. Curr Top Med Chem 13: 270‐282, 2013.
 297. Zamilpa R , Lindsey ML . Extracellular matrix turnover and signaling during cardiac remodeling following MI: Causes and consequences. J Mol Cell Cardiol 48: 558‐563, 2010.
 298. Zar JH . Biostatistical analysis. Pearson Prentice Hall, New Jersey, 2010.
 299. Zhou X , Yun J‐L , Han Z‐Q , Gao F , Li H , Jiang T‐M , Li Y‐M . Postinfarction healing dynamics in the mechanically unloaded rat left ventricle. Am J Physiol Heart Circ Physiol 300: H1863‐H1874, 2011.
 300. Zimmerman SD , Thomas DP , Velleman SG , Li X , Hansen TR , McCormick RJ . Time course of collagen and decorin changes in rat cardiac and skeletal muscle post‐MI. Am J Physiol Heart Circ Physiol 281: H1816‐H1822, 2001.
 301. Zimmermann W‐H , Melnychenko I , Wasmeier G , Didié M , Naito H , Nixdorff U , Hess A , Budinsky L , Brune K , Michaelis B , Dhein S , Schwoerer A , Ehmke H , Eschenhagen T . Engineered heart tissue grafts improve systolic and diastolic function in infarcted rat hearts. Nat Med 12: 452‐458, 2006.

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How to Cite

William J. Richardson, Samantha A. Clarke, T. Alexander Quinn, Jeffrey W. Holmes. Physiological Implications of Myocardial Scar Structure. Compr Physiol 2015, 5: 1877-1909. doi: 10.1002/cphy.c140067