Concept and evaluation of hibernating myocardium

Hibernating myocardium is a state of persistently impaired myocardial and l eft ventricular function at rest due to reduced coronary blood flows. It ca n be defined as an exquisitely regulated tissue successfully adapting its a ctivity to prevailing circumstances. It has been documented in patients wit h angina (chronic stable and/or unstable), acute myocardial infarction, hea rt failure and/or severe left ventricular dysfunction, and anomalous left c oronary artery from the pulmonary artery. The diagnosis of hibernating myoc ardium involves (a) documenting left ventricular dysfunction at rest and (b ) documenting that there is viable myocardium in the area of dysfunction. T ests commonly used for the latter are dobutamine echocardiography, Tl-201 i sotope studies, and positron image tomography. Revascularization, either by surgery or by interventional catheter techniques, has been shown to improv e or normalize the abnormal left ventricular function at rest.