Heart rate variability in depressive and anxiety disorders

Loss of normal autonomic nervous system control of heart rate and rhythm is an important risk factor for adverse cardiovascular events. After myocardi al infarction, reduction in beat-to-beat heart rate variability, a measure of cardiac autonomic innervation by the brain, is a strong predictor of dea th. With loss of vagal innervation, as is noted in patients with severe neu ropathy and in heart transplant recipients, there is loss of heart rate var iability. It is speculated that decreased parasympathetic innervation expos es the heart to unopposed stimulation by sympathetic nerves, individuals wi th high hostility scores and patients with anxiety or depressive disorders have low heart rate variability and may be at increased risk For cardiovasc ular death associated with coronary heart disease and arrhythmias. After my ocardial infarction, depressed patients exhibit higher mortality rates comp ared with nondepressed patients. Men with "phobic anxiety," a construct tha t appears to overlap substantially with panic disorder, also have higher ra tes of sudden cardiac death and coronary artery disease than control popula tions. The reduction in autonomic nervous system control to the heart may b e one link between psychopathology and heart disease. Although tricyclic an tidepressants reduce heart rate variability, at least one study has suggest ed that, in patients with panic disorder, treatment with the selective sero tonin reuptake inhibitor paroxetine normalizes heart rate variability. Henc e there is potential for the treatment of psychiatric disorders to affect p ositively the development and course of cardiovascular disease.