Depression, heart rate related variables and cardiovascular disease.

Depression is a risk factor for both onset of cardiovascular disease (CVD) and increased morbidity and mortality for those with CVD. Many, but not all studies, have found that depressed patients have alterations in heart rate (HR) and heart rate variability (HRV). This variability is thought to reflect autonomic dysfunction. HR tends to be higher in depressed patients and HRV lower. Both higher heart rates and lower HRV increase CVD risk. Beta-blockers reduce HR and increase HRV and should be considered for depressed patients with CVD, elevated HR and/or reduced HRV. Exercise has similar, but smaller effects. Few studies have examined the effects of psychological interventions on HRV and the results have either been modest or examined only short term. Future research should focus on well-characterized subgroups of depressed patients at risk for CVD with assessment of other important factors that may affect HRV and CVD risk. Studies of high frequency HRV need to account for the effects of respiration. 2010 Elsevier B.V. All rights reserved.