Modeling Reversible Mechanical Dysfunction in the Stunned Myocardium

Abstract

Although the ischemic dysfunction of the heart from coronary artery occlusion was observed before the 20th century, the concept of postischemic myocardial dysfunction was initially described by Vatner’s group in 1975 (33). Until 1982 the term myocardial stunning, related to the phenomenon of postischemic ventricular abnormality, was submitted and first coined by Braunwald and Kloner (11). They stated that the ischemic process may be “hit, run, and stun,”rather than a simple all-or-nothing process in which myocardial necrosis was caused when ischemia was prolonged and severe, but transient when brief or mild. In recent years it has been demonstrated experimentally that the mechanical dysfunction in postischemic or stunned myocardium persists after reperfusion despite the absence of irreversible damage and restoration of normal or near-normal coronary flow (6,7,9,39,60). In the other words, postischemic myocardial dysfunction is a fully reversible abnormality, if the reperfusion period is sufficient (11,14). On the whole, a number of clinical settings are potentially associated with myocardial stunning, including the percutaneous transluminal coronary angioplasty, unstable, variant angina, acute myocardial infarction with early repercussion, exercise-induced ischemia, cardiac surgery, and cardiac transplantation (7).