Relation of Depression to Heart Rate Nonlinear Dynamics in Patients ³60 Years of Age with Recent Unstable Angina Pectoris or Acute Myocardial Infarction

DANIEL E. VIGO; LEONARDO NICOLA SIRI; MARÍA S. LADRÓN DE GUEVARA; JOSÉ A. MARTÍNEZ MARTÍNEZ; RODOLFO D. FAHRER; DANIEL P.CARDINALI; OSVALDO MASOLI; SALVADOR M. GUINJOAN

AMERICAN JOURNAL OF CARDIOLOGY

Año: 2004 vol. 93 p. 756 - 760

0002-9149

Depression is common among older patients and it has been related to a worsened coronary prognosis. The basis for this association is controversial. The aim of this study was to ascertain whether patients with a recent acute coronary event show depression-related changes of heart rate variability (HRV) nonlinear dynamics. Alterations of the HRV have been recently shown to predict mortality in patients recovering from an acute myocardial infarction. In 52 patients >60 years (52% women) with recent (within 24 to 72 hours) unstable angina pectoris or myocardial infarction, we obtained conventional time- and frequency-domain HRV measurements, along with nonlinear HRV measurements, including SD of the instantaneous beat-to-beat variability (SD1), scaling exponent _1 (_1), and approximate entropy (ApEn) from 10-minute RR-interval recordings. We also evaluated the presence of clinical depression and measured its severity by means of a 21-item Hamilton Depression Scale. On admission to the coronary care unit, 19 patients (37%) were depressed; _1 was higher (1.23 _ 0.21 vs 1.03 _ 0.30, p <0.05), whereas SD1 (10.4 _ 3.7 vs 14.4 _ 7.3, p <0.05) and ApEn (0.98 _ 0.22 vs 1.16 _ 0.15, p <0.001) were lower in depressed patients. Also, _1 increased (r _0.31, p <0.05) and both SD1 (r _ _0.46, p <0.01) and ApEn (r__0.28, p <0.05) decreased with worsening depressive symptoms. In our sample, depression was associated with increased correlation and decreased complexity of the interbeat interval time series in older adults who had recently developed an acute coronary syndrome.