THE VIABLE MYOCARDIUM - EPIDEMIOLOGY, DETECTION, AND CLINICAL IMPLICATIONS

The success of fibrinolytic and other therapies has reduced the mortal ity of myocardial infarction. However, many survivors develop congesti ve heart failure. Medical treatment of this disorder has limited effic acy, and cardiac transplantation has limited availability. Contrary to previous teaching about ischaemic injury, roughly 40% of segments inv olved in myocardial infarction may subsequently recover, either sponta neously or after revascularisation. The persistence of such viable myo cardium means that previous approaches to treatment of myocardial infa rction must be reappraised. This review examines the pathogenesis of t his response, the techniques that may be used to identify the salvagea ble tissue, and the clinical implications. Myocardial revascularisatio n may improve symptom status, exercise capacity, and prognosis in sele cted patients with viable myocardium.