Heart Rate Variability in Essential Hypertension. Part II: Heart Rate Variability and its Circadian Rhythm in Hypertensive Patients

Abstract

Hypertensive patients are characterized by decreased values of the heart rate variability (HRV) components related to vagal activity. A reduction in parasympathetic activity significantly contributes to a disturbance in sympathetic and parasympathetic cardiovascular control in hypertension. The balance in autonomic control mechanisms is shifted towards a preponderance of sympathetic efferent activity. Also the circadian rhythm of HRV components dependent on sympathetic and parasympathetic activity is altered in essential hypertension. Heart rate variability is significantly reduced in patients with left ventricular hypertrophy secondary to hypertension. Left ventricular mass seems to be the most important determinant of the sympathovagal imbalance in hypertensive patients. Changes in HRV in patients with essential hypertension reflect disturbances in cardiac autonomic function. Assessment of heart rate variability may prove important role in the risk stratification in such patients.