Diastolic abnormalities of postischemic "stunned" myocardium

Myocardial "stunning" or postischemic contractile dysfunction in the absence of myocyte necrosis¹ has by convention been quantified using indexes of systolic function (i.e., segment shortening or wall thickening),^2,3 yet alterations in the diastolic components of the cardiac cycle associated with stunning remain largely undefined. Recent evidence suggests that abnormalities in diastolic function persist beyond the recovery of normal systolic function in patients rendered ischemic for brief (15 to 75 second) periods during percutaneous transluminal coronary angioplasty; thus, the diastolic properties of the stunned, reperfused myocardium may be of considerable clinical importance.^4,5 This report quantifies and compares indexes of both systolic contraction and isovolumic relaxation in a canine model of the postischemic, stunned myocardium.