THE COMPLEX RELATION BETWEEN MYOCARDIAL VIABILITY AND FUNCTIONAL RECOVERY IN CHRONIC LEFT-VENTRICULAR DYSFUNCTION

Preserved myocardial viability and recurrent symptomatic ischemia are the most widely accepted criteria indicating that coronary revasculari zation should take place in patients with postischemic left ventricula r dysfunction. However, the presence of viable myocardium within the i nfarct zone does not necessarily imply recovery of function after coro nary revascularization. The complex relation between the extent of tra nsmural necrosis and the degree of residual perfusion within the infar ct area plays an important role. However, independently of functional recovery, cell viability may have important clinical implications, sin ce it may improve long-term prognosis by attenuating left ventricular remodeling processes. Several different methods are used to detect hib ernating myocardium. Mounting evidence suggests that thallium-201 scin tigraphy is most sensitive in identifying tissue viability, whereas do butamine echocardiography is most specific in predicting functional re covery after revascularization, In between, myocardial contrast echoca rdiography is the only technique able to evaluate the microvascular in tegrity that is a condition sine qua non for both cell viability and l ater functional recovery. Combined information derived from these 3 di fferent approaches might be considered as the best way to understand h ow the combination of contractile, viable but noncontractile, and dead tissue affect resultant function and prognosis. (C) 1998 by Excerpta Medica, Inc.