Myocardial Viability by DE-MRI and Low-dose Dobutamine CMR

Introduction Dysfunctional myocardium that remains viable has the potential for contractile recovery after reperfusion. Dysfunctional but viable myocardium has been broadly divided into two closely linked pathophysiological states, myocardial hibernation and stunning. Stunned myocardium is the result of an ischemic insult leading to contractile dysfunction despite adequate reperfusion. Hibernating myocardium describes down-regulation of myocyte metabolism as a result of prolonged reduction in perfusion, or, in some cases, from repetitive episodes of myocardial stunning. Until recently scintigraphic techniques and stress echocardiography were the mainstay of diagnosis. The focus of this presentation is on the rapidly emerging clinical role of cardiovascular magnetic resonance imaging (CMR) in the detection of viable myocardium.