Compensatory and adaptive mechanisms in congestive heart failure

Knowledge of the basic alterations of central hemodynamics in congestive heart failure (CHF) has failed to explain many aspects of this important syndrome. Increasing attention has recently been paid to compensatory and adaptive mechanisms occurring after the initiating insult. Thus, new insights have been gained into the pathophysiology of contraction of hypertrophied myocardium and changes of adrenergic receptors in the myocardium due to chronically increased cardiac sympathetic tone. The role of the renin-angiotensin-aldosterone system in early and advanced CHF has been further elucidated and the role of the vasodilating and natriuretic atrial natriuretic peptide is undergoing further definition. New results further clarify the mechanisms leading to breathlessness and muscular fatigue in chronic CHF with emphasis shifting from the traditional concept of the importance of increased filling pressures to changes to the peripheral circulation and the exercising muscles. Although progress has been made in the understanding of the pathophysiology of CHF, many aspects are still poorly understood and await clarification.