[Anemia and myocardial ischemia: relationships and interferences]

Of all the pathologies that cause a critical reduction in oxygen supply to the tissues, atherosclerosis is undoubtedly the most frequent. At the coronary level, ischemia causes a critical imbalance in oxygen supply and demand to the myocardium. Protracting this condition induces necrosis since, when the heart surpasses certain limits, it is incapable of modulating its metabolism in relation to the availability of energy substrates. Recently, internists and cardiologists have been examining the role of anemia as a cause or cofactor in the development of myocardial ischemia. The drop in circulating erythrocyte mass and consequent drops in hemoglobin and hematocrit represent obstacles to oxygen transport and delivery to tissues. Tachycardia secondary to anemia leads to a shorter diastolic phase and reduction in arterial pressure, phenomena which are particularly prominent in acute anemia. Such changes can result in serious repercussions for people suffering from coronary disease, leading often to documentable myocardial damages. On the other hand, in chronic anemia the compensation phenomenom--represented by an increase in heart rate, cardiac output, ventricular volume and contractility--requires integrity of the cardiac apparatus, thus explaining the very serious repercussions of the anemic state for cardiac patients. Recently, the possibility of preventing and treating anemia-induced or anemia-exacerbated ischemia has been confirmed in the literature, albeit not unequivocably, demonstrating that this topic deserves particular attention.