Myocardial viability in chronic ischemic cardiomyopathy: similarities and discordance of different diagnostic approaches.

The presence of myocardial viability in patients with chronic ischemic cardiomyopathy has significant predictive value for improvement of left ventricular function after revascularization. Myocardial viability also predicts improved survival for patients undergoing coronary revascularization as opposed to medical therapy. Evaluation of viability can be pursued by different imaging techniques. Dobutamine stress echocardiography [or magnetic resonance imaging (MRI)] evaluates contractile reserve, while nuclear tests and late contrast-enhancement MRI evaluate cellular and tissue integrity. The different targets of these tests are frequently reflected into discordant results of viability evaluation. We review the different techniques available and describe their concordance from a mechanistic perspective.