Effect of reperfusion on ventricular mass, topography, and function during healing of anterior infarction.

The effect of reperfusion performed 2 h after left anterior descending coronary artery occlusion on in vivo changes (echocardiograms) in ventricular mass, topography, and function during postinfarction healing over 6 wk and postmortem topography (planimetry) and collagen (hydroxyproline) content at 6 wk were measured in dogs randomized to reperfusion (n = 12) and no reperfusion (n = 12). Compared with no reperfusion over the 6 wk, reperfusion resulted in less increase in systolic and diastolic volumes, less increase in ventricular mass, less infarct wall thinning, and mild improvement in global ejection fraction without any change in regional asynergy. Although reperfusion decreased the infarct collagen content at 6 wk, it reduced the in vivo expansion of the endocardial surface area; the elongation, diastolic bulge, echogenicity, and systolic thinning of the infarct zone; and the global shape index and aneurysm frequency. Thus reperfusion after 2 h attenuates regional and global dilation and produces less increase in mass during postinfarct healing than no reperfusion, so that the improvement in global systolic function cannot be attributed to global hypertrophy.