Congestive heart failure is the end product of a progressive series of events resulting from acute myocardial damage. Circulatory neurohormonal systems are activated during the acute phase of left ventricular dysfunction resulting from initial myocardial damage and again in the latter phase of decompensated heart failure. However, these neurohormonal mechanisms return to normal during the compensated stage of heart failure. Recent studies have suggested that autocrine/paracrine modulators of cardiovascular function are activated in the preclinical phase preceding the development of overt heart failure. The renin-angiotensin system in particular has been shown to modulate many of the chronic processes involved in the pathophysiology of cardiovascular disorders. Recent studies suggest that locally generated angiotensin II may contribute to the secondary structural changes seen in cardiovascular disorders, such as cardiac hypertrophy and remodelling, coronary artery disease, and atherosclerosis. Thus, inhibition of angiotensin formation with angiotensin converting enzyme (ACE) inhibitors, particularly at the tissue level, may provide valuable cardioprotective effects. Additional evidence points to the efficacy of ACE inhibitors in preventing the progression of asymptomatic left ventricular dysfunction to overt heart failure.