One of the earliest structural changes in the heart adapting to hypertension is left ventricular hypertrophy, which can now be exactly measured by echocardiography. Left ventricular hypertrophy increases the incidence of coronary artery disease, heart failure, and sudden death severalfold, independent of the blood pressure levels. Left ventricular hypertrophy requires specific antihypertensive therapy that controls both high blood pressure and increased left ventricular mass. Preliminary data from clinical studies indicate that regression of left ventricular hypertrophy leads to a better cardiovascular prognosis. Sympatholytic substances, angiotensin-converting enzyme (ACE) inhibitors, and calcium antagonists are antihypertensive agents that effected adequate reductions in blood pressure as well as regression of left ventricular hypertrophy.