From the clinical point of view, the diagnosis of "hibernating myocardium" is of predominant importance in patients with LV-dysfunction, because a prediction of a possible functional recovery allows to determine risk and outcome of an intervention. Alone or in combination, thalliumscintigraphy with reinjection and dobutamine echocardiography are suitable to detect "hibernating myocardium". In addition, morphological investigations of biopsies taken from hibernating regions permit the evaluation of structural changes. The spectrum of alterations is wide and at a certain degree of severity they are irreversible. The relation between clinical and morphological results provides further insight into the degree of injury and of functional recovery after adequate revascularization.