CLINICAL CONSEQUENCES OF THE AUTONOMIC IMBALANCE IN HYPERTENSION AND CONGESTIVE-HEART-FAILURE

The reduction of coronary mortality is not as large as one would expec t from the observed blood pressure lowering in trials of antihypertens ive medications. This is not surprising; hypertension is a complex dis ease where the high blood pressure is only one of numerous coronary ri sk factors. Sympathetic overactivity in hypertension, independent of t he blood pressure, may be conducive to premature atherosclerosis by in ducing insulin resistance and dyslipidemia. Through its trophic effect on blood vessels, sympathetic overactivity potentiates vasoconstricti on. This, in turn, accelerates hypertension and the metabolic syndrome . The hypertrophy of small coronary arterioles decreases the coronary reserve and enhances coronary spasms. Tachycardia, which is due to inc reased sympathetic tone and a decreased parasympathetic tone, favors a rrhythmias and sudden death in congestive heart failure and hypertensi on. increased hematocrit is frequently found in male patients with hyp ertension, and high hematocrit is a predictor of coronary heart diseas e/thrombosis. The increase of hematocrit is in part due to an alpha ad renergic postcapillary venoconstriction. Enhanced sympathetic drive, i nsulin resistance and dyslipidemia have been demonstrated also in cong estive heart failure, but the clinical importance of these findings is not fully understood.