Abstract
Mounting evidence shows that elevated heart rate is associated with a greater risk of developing hypertension and atherosclerosis and that it is a potent predictor of cardiovascular morbidity and mortality. These relationships have been shown not only in general populations but also among hypertensive individuals, with important implications for the treatment of hypertension. Recent evidence suggests that the predictive power of resting heart rate for cardiovascular mortality is even greater than indices derived from analysis of heart rate variability. In spite of this evidence heart rate is still overlooked as a risk factor, but the fact that in most studies the risk related to fast heart rate remained highly significant after controlling for major risk factors for atherosclerosis suggests that it plays a direct role in the induction of the risk. The clustering of several risk factors for coronary artery disease in subjects with fast heart rate suggests that sympathetic overactivity accounts for the increased cardiovascular morbidity in subjects with tachycardia. Moreover, experimental studies both in animals and human beings suggest that the heamodynamic disturbances related to high heart rate have a direct impact on the arterial wall promoting the development and the rupture of atherosclerotic plaques. Data obtained in the experimental animal and pooled data from intervention studies in patients with myocardial infarction or congestive heart failure suggest that drug-induced reduction of heart rate may be beneficial in several clinical conditions. Tachycardia (heart rate ≥ 80 bpm) has been found in over 30% of the hypertensive patients and thus reduction of high heart rate appears as a desirable additional therapeutic goal in a large proportion of the hypertensive population. Several antihypertensive agents have shown good potential for decreasing the fast heart rate in hypertension. In the future, goal of antihypertensive treatment in patients with tachycardia will be to prevent or reverse those functional abnormalities of the autonomic nervous system which accompany the hypertensive condition.
Keywords: cardiovascular, hypertension, risk, heart rate, sympathetic
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