Assessment of myocardial viability by cardiovascular magnetic resonance imaging

tional but viable myocardium may improve left ventricular function and long-term survival Non-contractile yet viable myocardium can be caused by acute, subacute and chronic states of abnormalities of myocardial perfusion. Frequently used paradigms to describe dysfunctional viable myocardium are stunning and hibernation, which both refer to reversible left ventricular contraction impairment. Hibernation describes the concomitant reduction of perfusion and contractility, whereas stunning characterizes contractile impairment persisting after complete return of blood flow. Stunning has been observed in many clinical situations, such as unstable angina Hibernation is thought to be characterized by chronically reduced coronary perfusion. It is believed to represent an adapted state in which contractile function is diminished in order to match the decreased supply of substrates and oxygen to the myocardium.