+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Experimental myocardial infarction: XII. Dynamic changes in segmental mechanical behavior of infarcted and non-infarcted myocardium



Experimental myocardial infarction: XII. Dynamic changes in segmental mechanical behavior of infarcted and non-infarcted myocardium



American Journal of Cardiology 37(6): 853-859



The mechanical behavior of ischemic myocardium was studied in anesthetized open chest dogs. In each animal, a small well localized myocardial infarction was produced by ligation of a single ventricular branch of the left circumflex coronary artery. Serial in situ measurements of segment length were made by mercury-in-Silastic gauges sutured directly to the left ventricular surface. After coronary ligation, systolic aneurysmal bulging of the ischemic segment was uniformly noted. This was quantified as follows: normalized segment length change in this region, expressed in muscle lengths (where muscle lengths = phasic segment length amplitude/end-diastolic segment length), immediately increased from 0.06 +/- 0.01 (standard error of the mean) to 0.10 +/- 0.02 muscle lengths (+67 percent, P less than 0.02). Over a 6 hour period, muscle lengths progressively declined to near control values, but retained an aneurysmal contour. End-diastolic segment length increased 5 percent above control values after coronary occlusion and remained fixed at this level for 6 hours. In contrast, noninfarcted myocardium exhibited no significant changes in muscle length or end-diastolic segment length. These studies demonstrate that the degree of systolic aneurysmal bulging in infarcted myocardium, although initially great, resolves within 6 hours but retains an aneurysmal contour. These findings are consistent with either partial return of contractility or diminished local compliance, but persistence of an aneurysmal shape favors the latter mechanism. The fixed increase in end-diastolic segment length suggests that "stress-relaxation" takes place in the infarcted region. It is possible that diminished compliance in zones of infarction, previously noted after several days, begins within a few hours after the onset of ischemia.

Please choose payment method:






(PDF emailed within 0-6 h: $19.90)

Accession: 040099756

Download citation: RISBibTeXText

PMID: 1266750

DOI: 10.1016/0002-9149(76)90109-0


Related references

Abnormal coronary vasodilator function of non-infarcted and infarcted myocardium in acute myocardial infarction. Circulation 96(8 Suppl. ): I747, 10/21/97, 1997

Opposite effects of the remodeling of infarcted and non-infarcted myocardium on left ventricular function early after infarction in humans. An echocardiographic study in patients examined before and after myocardial infarction. International Journal of Cardiology 60(1): 81-90, 1997

Mechanical behavior of non-infarcted myocardium adjacent to scarred infarcted tissue during left ventricular remodeling. Circulation 86(4 Suppl. 1): I170, 1992

Beneficial angiogenesis induced by over-expression of human hepatocyte growth factor in non-infarcted and infarcted myocardium Potential gene therapy for myocardial infarction. Circulation 98(17 Suppl. ): I321, 1998

Transplantation of fetal myocardial tissue into the infarcted myocardium of rat. A potential method for repair of infarcted myocardium?. Circulation 94(9 Suppl.): Ii332-6, 1996

Myocardial viability assessed by dobutamine echocardiography soon after myocardial infarction Influence of myocardial echocontrast opacification of infarcted area and TIMI grading of infarcted related artery. Journal of the American College of Cardiology 0(SPEC ISSUE): 360A, 1994

Mismatch of infarcted and non infarcted myocardium infarct expansion shape distortion remodeling and reduced survival by exercise in rats with chronic infarction. European Heart Journal 13(ABSTR Suppl.): 155, 1992

Blood Circulation Measurement in Experimental Myocardial Infarct and Alteration of the Blood Circulation in the Infarcted and Non-Infarcted Myocardium by some Poisons. Naunyn-Schmiedebergs Archiv für Experimentelle Pathologie und Pharmakologie 246: 240-286, 1963

Increase of type i and iii collagen messenger rna and protein in the infarcted and non infarcted rat heart after myocardial infarction. Journal of Molecular & Cellular Cardiology 23(Suppl. 5): S60, 1991

Type I and III collagen mRNA and protein increase in the infarcted and non-infarcted rat heart after myocardial infarction. Journal of Molecular & Cellular Cardiology 24(Suppl. 5): S50, 1992

Differential expression of three types of nitric oxide synthase in both infarcted and non-infarcted left ventricles after myocardial infarction in the rat. International Journal of Cardiology 76(2-3): 135-145, November-December, 2000

Assessment of nonuniformity of the transmural myocardial velocity profile by angle corrected tissue Doppler imaging Characterization of normal, transmurally infarcted and nontransmurally infarcted myocardium. Circulation 104(17 Suppl.): II 628, 2001

Risk of myocardium adjacent to infarcted myocardium: electrocardiographic, metabolic and scintigraphic evidence within the first week of acute myocardial infarction. American Journal of Cardiology 57(13): 1034-1040, 1986

Successful transplantation of foetal cardiomyocytes into the infarcted myocardium of rat A potential method for repair of infarcted myocardium. European Heart Journal 17(ABSTR Suppl. ): 268, 1996

Successful transplantation of fetal cardiomyoblasts into the infarcted myocardium of rat A potential method for repair of infarcted myocardium. Circulation 92(8 Suppl. ): I50-I51, 1995