Uncontrolled hypertension increases the workload of the left ventricle causing the development of hypertrophy and an increase in myocardial oxygen consumption that may precipitate ischemia because of inadequate oxygen delivery related to accelerated coronary atherosclerosis. Control of the hypertension should prevent the further development of hypertrophy, delay the development of fibrosis and possibly also slow the rate of development of atherosclerosis. Furthermore, when myocardial function is impaired because of hypertrophy or other myocardial diseases, the level of blood pressure becomes an important determinant of left ventricular performance. Regardless of the level of arterial pressure, vasodilator drugs that lower arterial pressure may result in marked improvement in left ventricular performance and relief of symptoms of left ventricular failure. Therefore, control of blood pressure in the presence of heart disease may involve treatment of normotensive patients to bring them into a lower normotensive range as well as the more traditional treatment of hypertensives to bring them into the normotensive range. Although this scenario is consistent with conventional wisdom and clinical experience, intricacies of the relationship between hypertension, hypertrophy, myocardial oxygen delivery, atherosclerosis and intramyocardial blood flow distribution remain poorly understood. Until these aspects of the natural history of heart disease are better worked out therapy will remain largely empirical.