Modification of Ventricular Function by Hypercontraction of the Surviving Heart Muscle Following Myocardial Infarction

Abstract

During and after a myocardial infarction, variable amounts of left ventricular¹ muscle are lost through the process of necrosis and re­placement by scar tissue. The compensatory mechanisms that follow recovery from the infarct and the success of these mechanisms deter­mines the overall functional status of the ventricle and, to a large part, the symptomatic status of the patient. In reviewing left ven­tricular cine angiograms of postinfarction patients, it appears that some ventricles exhibit a greater than usual degree of contraction in the noninfarcted portion as a compensation for poor contraction in the scarred portion of the ventricle. The purpose of this study was to further investigate this phenomenon of regional hypercontrac­tion as a compensatory mechanism in postinfarct patients. The objec­tives were to quantitate the extent of these hypercontracting seg­ments by angiographic techniques, to determine their incidence and significance, and to evaluate the conditions under which they develop.