Depression, Heart Rate Variability, and Acute Myocardial Infarction

Abstract

Background-Clinical depression is associated with an increased risk for mortality in patients with a recent myocardial infarction (MI). Reduced heart rate variability (HRV) has been suggested as a possible explanation for this association. The purpose of this study was to determine if depression is associated with reduced HRV in patients with a recent MI. Methods and Results-Three hundred eighty acute MI patients with depression and 424 acute MI patients without depression were recruited. All underwent 24-hour ambulatory electrocardiographic monitoring after hospital discharge. In univariate analyses, 4 indices of HRV were significantly lower in patients with depression than in patients without depression. Variables associated with HRV were then compared between patients with and without depression, and potential confounds were identified. These variables (age, sex, diabetes, and present cigarette smoking) were entered into an analysis of covariance model, followed by depression status. In the final model, all but one HRV index (high-frequency power) remained significantly lower in patients with depression than in patients without depression. Conclusions-We conclude that greater autonomic dysfunction, as reflected by decreased HRV, is a plausible mechanism linking depression to increased cardiac mortality in post-MI patients.

Circadian affective, cardiopulmonary, and cortisol variability in depressed and nondepressed individuals at risk for cardiovascular disease

“…These findings are in contrast to our previously reported stress findings in the laboratory, which indicated HRV and cortisol differences , and to other laboratory investigations (e.g., Agelink et al, 2002;Carney et al, 2005;Carney et al, 2001). Recent results from the Heart and Soul study (Gehi, Mangano, Pipkin, Browner, & Whooley, 2005) support our HRV findings: In a cross-sectional design with 873 CVD patients (195 depressed), the authors did not find a relationship between depression and time-or frequency-domain measures of HRV that were measured by 24-hour ambulatory electrocardiography.…”

“…Several studies have reported basal hypercortisolism (e.g., Gotthardt et al, 1995;Plotsky, Owens, & Nemeroff, 1998), hypercortisolism in response to stress (for a review, see Burke, Davis, Otte, & Mohr, 2005), or elevated cortisol levels after awakening in depression (e.g., Bhagwagar, Hafizi, & Cowen, 2005). A variety of studies have suggested that depressed subjects have less heart rate variability (HRV) than nondepressed controls (e.g., Agelink, Boz, Ullrich, & Andrich, 2002;Carney et al, 2005;Carney et al, 2001), even when controlled for potential confounds such as age, sex, and smoking, suggesting autonomic dysregulation. …”

The Hospital Anxiety and Depression Scale depression subscale, but not the Beck Depression Inventory-Fast Scale, identifies patients with acute coronary syndrome at elevated risk of 1-year mortality

“…Previous studies of depression in this area have typically involved assessment of patients using clinical interviews and lengthy patient-completion questionnaires [3,8,18]. This approach is not feasible in most centres.…”

“…Assessment methods for depression have traditionally involved either clinical interviews conducted by experienced mental health professionals or lengthy selfcompletion questionnaires [3,18]. These preclude routine assessment of depression in most cardiac settings.…”

Depression and Cardiovascular Disease

“…Alterations in cardiac autonomic tone 16 Common genetic vulnerability 17 Enhanced activity of the hypothalamic pituitary-axis 18 Greater platelet activation 19 Increased catecholamine levels 20 Increased whole blood serotonin 21 Inflammatory processes 22 Lower omega-3 fatty acid levels 23 Mental-stress induced ischemia 24 Toxicity of tricyclic antidepressants 25 Potential behavioral mechanisms Dietary factors 26 Lack of exercise 27 Medication nonadherence 28 Poor social support 29 …”