Comparing the Effects of Acute Homogeneous Myocardial Infarct with Heterogenous Microinfarct on Left Ventricular Function Using MRI

Maythem Saeed¹, Steven W. Hetts¹, Loi Do¹, Mark Wilson¹

The purpose was to differentiate the deleterious effects of major-vessel and micro-vessel occlusion on left ventricular function using MRI. Pigs (n=24) were divided into 3 groups: 1) control (no-infarct), 2) subjected to 90min of LAD artery occlusion/reperfusion and 3) subjected to coronary microemboli delivered into the LAD. At 3 days after coronary intervention, cine and viability images were acquired using MRI. The sizes of homogeneous infarct and microinfarct measured were 171% and 6.20.6% LV mass (P<0.01). Surprisingly, the effect on LV ejection fraction was identical in both interventional procedures, suggesting that different mechanisms govern the decline in LV function.