Assessment of Regional Viability in the Infarct Zone Following Myocardial Infarction.

The goal of reperfusion strategies in patients with acute myocardial infarction is to salvage myocardium within the infarct zone at risk from the acute occlusion. The status of wall motion and thickening within the infarct zone is an imprecise guide to the extent of salvage and viability within the infarct zone, based on the well-described phenomenon of myocardial stunning. However, knowledge of significant salvage and preserved viability within an infarct zone soon after infarction has important implications regarding clinical decision making for catheterization and potential revascularization: given preserved viability, restoration of normal coronary flow in the setting of a severe residual stenosis or occlusion would be expected to result in significant recovery of regional, and possibly global left ventricular function, with attendant implications for prognosis and outcome.This review will critically explore imaging techniques regarding their ability to discern myocardial viability within the infarct zone soon after myocardial infarction, including electrocardiography, angiography, echocardiography, and radionuclide studies of myocardial perfusion, metabolism and cell membrane integrity.