Experimental myocardial infarction in dogs reduced left ventricular compliance 3-5 days post-infarction compared to sham-operated controls (P<0.05), attributable to increased stiffness of the infarcted area.
Does experimental myocardial infarction alter left ventricular compliance and filling pressures in dogs compared to sham operation?
Stiffening of the ischemic myocardium occurs within the first 5 days after infarction, demonstrating that elevated left ventricular filling pressure does not necessarily indicate ventricular dilatation.
valor p: p=<0.05
Compliance of the infarcted left ventricle was studied in dogs 3-5 days after occlusion of the left anterior descending coronary artery. Compliance was assessed from postmortem pressure-volume curves and from pressure-length measurements (mercury-in-silastic segment length gauges) made both in vivo and postmortem. Postmortem pressure-volume curves showed reduced compliance compared to sham-operated animals. Postmortem pressure-length curves of infarcted and adjacent normal myocardium indicated that the diminished total compliance could be attributed to an increase in stiffness of the infarcted area. This was confirmed by in vivo end-diastolic pressure-length changes produced by transient aortic occlusion. The infarcted area was akinetic, showing neither contraction nor aneurysmal bulging. In addition, anesthetized dogs with infarcts, when compared with sham-operated animals, had similar left ventricular end-diastolic volumes (indicator dilution method), but higher left ventricular end-diastolic pressures. Taken with previous observations, which show that systolic aneurysmal bulging is uniformly present at the onset of ischemia, these results indicate that stiffening of the ischemic myocardium occurs during the first 5 days after infarction, and show that elevation of left ventricular filling pressure does not necessarily signify ventricular dilatation. The results also suggest a mechanism whereby ventricular performance may improve during recovery from acute myocardial infarction.
Hood et al. (Wed,) conducted a other in Experimental myocardial infarction (n=27). Coronary artery ligation vs. Sham operation was evaluated on Left ventricular compliance (pressure-volume curves) (p=<0.05). Experimental myocardial infarction in dogs reduced left ventricular compliance 3-5 days post-infarction compared to sham-operated controls (P<0.05), attributable to increased stiffness of the infarcted area.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: