Treatment of cardiac failure

Abstract

Cardiac failure is the clinical syndrome that results when the heart is unable to pump blood in an amount that adequately meets the metabolic needs of the body. It is the end result of a heterogeneous group of disorders that, in most cases, directly or indirectly impair myocardial contractility. Cardiac failure also can occur when the normal myocardium is presented suddenly with a load that exceeds its capacity and when ventricular filling is restricted. Implicit in the definition of cardiac failure is the requirement that an abnormality of cardiac function induces the basic hemodynamic consequences of reduction of cardiac output and increase in venous pressure behind one or both ventricles. This is in contrast to the low-output states due to diminished systemic venous return and the congestive states that accompany primary renal and hepatic disorders. The recognition of heart failure rests on the identification of a group of characteristic clinical findings that vary greatly depending on whether the failure is acute or chronic, predominantly left or right sided and low or high output in nature. The variability of the clinical features arises in large part from the fact that they result both from the underlying hemodynamic abnormality and from the compensatory mechanisms that are invoked when myocardial performance is impaired.