Myocardium ceases contracting a few seconds after the onset of ischemia. Thereafter, the affected myocardium stretches rather than shortens with each systole. This contractile deficit does not disappear if one salvages the damaged tissue by timely reperfusion. Rather, it persists for a few or many hours depending on the severity of the injury. The failure of the tissue to resume contraction after reperfusion was totally unexpected when it first was observed some 27 years ago,1 but the fact that it occurs has been confirmed by many investigators studying the effects of ischemia and reperfusion in both animal and human hearts. Moreover, this regional contractile failure may be very important because it can cause enough of a decrease in cardiac output to exacerbate preexisting congestive cardiac failure or may be sufficient to cause the development of congestive failure in a previously asymptomatic patient...