Cardiac parasympathetic dysfunction related to depression in older adults with acute coronary syndromes

Objective: To determine whether depression is associated with cardiac autonomic alterations in elderly patients with recent acute coronary syndromes (ACSs). Methods: Cross-sectional study on the association between a major depressive episode or isolated depressive symptoms (21-item Hamilton depression score) and heart rate variability abnormalities in 56 adults (31 women, 55%) 60 years of age and older with a recent (24-72 h) myocardial infarction (MI) or unstable angina (UA). Results: Spectral and nonspectral parameters of respiratory sinus arrhythmia, indicative of parasympathetic activity on the heart, were decreased in patients with depression (high-frequency heart rate variability [log ms(2)] 2.12 +/- 0.4 vs. 2.52 +/- 0.5, P = .024; pNN50 [%] 1 +/- 2 vs. 9 +/- 15, P = .006; and rMSNN [ms] 16 6 vs. 28 +/- 22, P = .009). Also, high-frequency heart rate variability decreased with increasing depressive symptom severity. Conclusion: In a sample of older adults suffering from ACSs, depression was associated with impaired parasympathetic control of the heart. (C) 2004 Elsevier Inc. All rights reserved.