[Angina pectoris without coronary stenosis--current concepts].

This review aims at demonstrating current concepts for the occurrence of angina pectoris (AP) and myocardial ischemia in patients without significant epicardial stenoses based on typical clinical examples. For applying these concepts, it is of utmost importance to clinically distinguish patients with resting AP only from those with exercise-induced symptoms or both. Resting AP may not only be caused by plaque rupture and subsequent coronary thrombosis, but may also be due (especially when repeated attacks occur in the early morning hours) to coronary vasospasm (in the microvasculature as well as in epicardial coronary segments). Similarly, exercise-induced AP and/or a pathological exercise test result may not only be caused by severe coronary stenoses, but may also be due to a reduced coronary perfusion reserve secondary to microvascular dysfunction. Hence, a pathological non-invasive stress-test result should not be necessarily described as "false positive" in case of the absence of any significant stenosis. In principle, proatherogenic cardiovascular risk factors are not only associated with atherosclerotic coronary artery disease (CAD), but also with the occurrence of a coronary vasomotility disorder. Both disease entities are characterised by the occurrence of myocardial ischemia. So far, the exact pathomechanism of respective subforms of coronary vasomotility disorders has not yet been not elucidated in detail. Endothelial dysfunction, abnormalities of the smooth muscle cells in the media as well as genetic predisposition or specific immunological abnormalities are discussed as underlying reasons. Intracoronary provocative testing (such as the acetylcholine-test) may help to diagnose as well as to differentiate the different subforms of coronary vasomotility disorders.