Over the years, Rahimtoola popularised the term hibernation to describe the situation of chronic obstructive coronary artery disease resulting in chronic contractile dysfunction, which could be reversed after surgical revascularisation.¹ Based on this observation, physicians became aware that chronic left ventricular (LV) dysfunction was not necessarily an irreversible process, and that in the presence of dysfunctional but viable myocardium, recovery of function was possible after revascularisation. In a large observational study, Rahimtoola subsequently demonstrated that this was not a rare phenomenon, but rather this situation occurred frequently in the clinical setting.²

Over time, among many other aspects of hibernation, three issues have come to the fore:

• Is resting perfusion reduced or normal in hibernating myocardium?

• Which technique is ideal to detect hibernation and predict recovery of function after revascularisation—in particular, nuclear imaging or dobutamine echocardiography?

• What is the optimal timing to assess recovery of function after revascularisation?

In this issue of Heart, Alamanni and colleagues³ have carefully evaluated 23 patients with chronic LV dysfunction who underwent revascularisation. Usefully, information relating to the above three issues can be derived from this study.

FLOW RESERVE

At first, hibernating myocardium was considered to have reduced resting blood flow,² but recent data demonstrated that patients frequently have normal resting flow. Rather, the flow reserve of these patients was reduced.⁴ Over the years, this resulted in an ongoing debate since …