End-organ disease in hypertension: What have we learned?

The major target organs that suffer from sustained hypertension are the heart, kidneys, and brain. Cardiac adaptation to arterial hypertension consists of left ventricular hypertrophy (LVH) of the concentric type, that is, an increase in wall thickness at the expense of chamber volume. However, LVH can no longer be considered a simple adaptive myocardial process serving to compensate for the increase in af-terload and bring left ventricular wall stress back to normal. Data from the Framingham cohort have shown that the occurrence of LVH drastically increases the risk of sudden death and other cardiovascular morbidity and mortality irrespective of the levels of arterial pressure. Renal adaptation to arterial hypertension consists of a decrease in renal blood flow with elevations in filtration fraction and renal vascular resistance. With progressive hypertensive cardiovascular disease, glomerular filtration rate will fall as well. Recent data in patients with mild-to-moderate hypertension demonstrate that despite "efficacious" antihypertensive therapy, one-third to one-half of hypertensive patients may experience a significant decline in renal function. Cerebrovascular adaptation to hypertension consists of micro- and macrovascular disease leading to vascular dementia, or ischemic or hemorrhagic stroke. Cerebrovascular autoregulation, the mechanism by which cerebral blood flow is maintained, despite changes in arterial pressure, may be altered in hypertension.