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.