ABSTRACT
Heart failure often is defined as the state where the heart cannot supply adequate blood flow to meet tissue metabolic demands, or only can do so when cardiac filling pressures are elevated. Heart failure involves abnormalities of systolic or diastolic function, or both. Multiple cardiac and systemic “compensatory” mechanisms are activated to sustain cardiac output, systemic arterial blood pressure, and tissue perfusion pressure. The etiologic diagnosis is the cause of the initiating cardiac injury. Cardiac lesions create pathophysiologic abnormalities that might eventually lead to the clinical signs of congestive heart failure (CHF). Contractility or myocardial failure is characterized by a depressed inotropic state and ventricular systolic dysfunction. The general appearance of the affected ventricle by echocardiography has the key abnormalities of ventricular chamber dilation with reduced ejection fraction. Volume overload heart failure usually is caused either by an incompetent valve or an abnormal systemic-to-pulmonary shunt, or sometimes both.
