Left ventricular hypertrophy: its prime importance as a controllable risk factor.

Left ventricular hypertrophy, which is defined as an abnormal increase in the mass of the left ventricle, has become recognized as an important independent risk factor for predicting several untoward cardiac events, including myocardial infarction, congestive heart failure, and sudden death. The presence of left ventricular hypertrophy is difficult to detect by electrocardiography but can be accurately assessed by echocardiography. Left ventricular hypertrophy can be detected in about 5% of all hypertensive patients by electrocardiography but is found in about 50% by echocardiography. Although it is possible to restore left ventricular mass to normal by controlling hypertension with pharmacotherapy, several commonly prescribed antihypertensive medications, including diuretics and vasodilators, have failed to demonstrate the ability to reverse left ventricular hypertrophy. Other agents, including most beta-blockers, have been found to reverse it. Reversal may take 18 to 24 months from the initiation of therapy. This reversal may be accompanied by an increase in cardiac index, reductions in total peripheral resistance, and improvements in the diastolic properties of the left ventricle. It has yet to be determined whether these improvements reduce the risk of myocardial infarction, heart failure, and sudden death. However, it is likely that some antihypertensive medications may be superior to others in reducing long-term cardiac risks.