Coronary artery disease is the most common cause of congestive heart failure. More than 70% of the patients with heart failure symptoms have underlying coronary disease, whereas the majority of patients with ischaemic cardiomyopathy have a previous myocardial infarction.^1,2 The prognosis of these patients is poor, particularly in men, and many of them need intermittent hospitalisation because of decompensated heart failure. In the near future, chronic heart failure will be encountered even more often, as our population ages.^1,2 The clinical characteristics of the patient, the presence of ischaemia, and severity of left ventricular dysfunction determine the prognosis in heart failure.

Traditionally, ischaemic left ventricular dysfunction was considered an irreversible process. In patients with ischaemic cardiomyopathy, medical treatment was regarded as the only management option. However, more than two decades ago, Diamond and Rahimtoola recognised that left ventricular dysfunction in these patients is not always permanent and launched the theory of myocardial hibernation.^3,4 Hibernating myocardium is defined as chronic reversible contractile dysfunction secondary to coronary artery disease. The presence of hibernating myocardium has become an additional motive to perform coronary revascularisation. In fact, if a substantial amount of hibernating myocardium is present, coronary revascularisation may substantially improve regional and global contractile function in selected patients with ischaemic cardiomyopathy.⁵

This article will focus on the clinical importance and identification of myocardial viability in patients with chronic ischaemic left ventricular dysfunction.

PATHOPHYSIOLOGY OF VIABLE MYOCARDIUM

In patients with ischaemic cardiomyopathy several (patho)physiological conditions of the myocardium may coexist. Often there are areas with preserved contractile function supplied by coronary arteries without significant stenoses. On the other hand, contractile dysfunction can be observed in myocardial regions that are subtended by a stenotic or occluded coronary artery. Coronary occlusion may cause cellular death resulting in irreversibly scarred myocardium.⁶ Alternatively, the reduced …