Therapy for myocardial stunning

Myocardial stunning, or postischemic dysfunction, is defined as delayed recovery of systolic and/or diastolic function of viable myocardium despite restoration of coronary flow after an ischemic insult (4). The severity and duration of myocardial stunning is highly dependent on the duration and severity of the previous ischemic insult (2). Thus, clinically significant myocardial stunning can be seen only after severe ischemic insult, especially after reperfusion therapy for acute myocardial infarction and during the recovery period after coronary artery bypass surgery (2). However, in the former condition some of the cases of delayed recovery of function may be attributed to delayed improvement of perfusion by either delayed recanalization or recuitment of collaterals, and in the latter condition a delayed recovery from hibernation or new ischemic insult due to acute occlusion of the bypass grafts may be the reason for the continuous myocardial dysfunction (2). Thus, in the clinical setting pure myocardial stunning should be diagnosed only after simultaneous demonstration of persistent mechanical dysfunction despite restoration of normal coronary perfusion. Myocardial stunning has also been described following less severe ischemia induced by partial coronary stenosis following exercise in both animals and humans (2). This form of myocardial stunning following exercise treadmill testing may serve as a marker of severe multivessel coronary artery disease (2). It might be that in daily life uncontrolled effort induced ischemia may result in prolonged and clinically relevant myocardial stunning in patients with severe coronary artery disease.