[Revascularization versus transplantation in patients with limited ejection fraction].
Ventricular dysfunction caused by ischemia is frequently a consequence of episodes of myocardial infarction which occur in the context of coronary disease, as well as of the ischemic situation in patients with severe failure in the main coronary arteries. The physiopathological mechanisms, as well as the therapeutic possibilities, are different in the case of diagnosed necrosis of myocardium or in situations of its circulatory deficiency, and, in the latter case, they depend on the period of absence of blood flow to the ischemic area, and on the occurrence of reperfusion of the area at the end of the ischemic event, the existence of an adequate collateral flow, etc. Classically, moderate degrees of ischemic ventricular dysfunction were considered as a preferential indication for revascularization surgery, together with the existence of coronary disease anatomically suitable for bypass. However, severe degrees of ventricular dysfunction were regarded as a contraindication to surgery, as they were considered irreversible due to an ischemic myocardiopathy which could not be palliated by an ulterior revascularization. These patients were referred to heart transplantation or to medical treatment when they did not fulfill the criteria to be included in transplantation programmes. In a later stage, due to a scarcity of donors for transplantation and to the disappointing results of pharmacological treatment in these patients, revascularization operations begun to be performed on patients with severe heart failure. Although initial results were not comparable to the ones obtained nowadays, work continued on this track and rapid improvement was achieved when particular clinical and diagnostic patterns were followed. Thus the concept of myocardial viability was created, presently being a central criterion in deciding which patients should go through revascularization. There are different methods to assess viability, and new ones are added to the diagnostic arsenal every day. With an adequate assessment of this concept, it is presently possible to really predict which patients may obtain clinical and functional improvement from their coronary disease in spite of severe deterioration of their cardiac function. This article analyzes the physiopathology of ventricular dysfunction, present methods to detect the viability of myocardial cells, as well as present indications and results obtained with ventricular revascularization in patients with severe depression of ventricular function as an alternative, currently well established, to heart transplantation.
Servicio de Cirugía Cardiovascular, Hospital Reina Sofía, Córdoba.
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Muñoz Carvajal
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Concha Ruiz
D002303:Cardiac Output, Low / Q000503:physiopathology; D016027:Heart Transplantation; D006801:Humans; D009204:Myocardial Revascularization; D017682:Myocardial Stunning; D018579:Patient Selection; D013318:Stroke Volume; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology / Q000601:surgery*