POWER SPECTRAL-ANALYSIS OF HEART-RATE IN SUBJECTS OVER 100 YEARS OLD

Altered autonomic regulation of cardiac function may contribute to the onset of cardiovascular disease and provide a substrate for malignant ventricular arrhythmias. This study was designed to assess cardiovasc ular neuroautonomic status in healthy subjects with short-term power s pectral analysis of heart rate variability, including a group over 100 years of age, to identify a neuroautonomic pattern that could help to protect ultra-centenarians against cardiovascular disease. One hundre d and twelve subjects (22 men and 90 women, age range 20 to 107 years) were subdivided into five age groups: <40 years (N=26, mean age 30.6/-0.9); 41 to 60 years (N=27, mean age 51.9+/-1.2); 61 to 80 years (N= 37, mean age 70.3+/-1.1); 81 to 100 (N=10, mean age 85.2+/-0.8) and ol der than 101 years (N=13, mean age: 103.6+/-0.6). Power spectral analy sis with autoregressive algorithm provides two indexes of autonomic ac tivity: a low-frequency component oscillating around 0.10 Hz, mainly r eflecting sympathetic activity and a high-frequency component around 0 .30 Hz, reflecting parasympathetic activity. Subjects 40 years of age or younger had significantly higher spectral high-frequency power valu es expressed in logarithmic form than the other age groups (P<0.05), t he age group from 41 to 100 years had values similar to those of the o ther groups. However, the age group over 101 years had significantly h igher values than the group from 81 to 100 years (P<0.05). Low-frequen cy spectral density expressed in logarithmic form and in normalized un its decreased with age (P<0.0001). These data confirm an age-related d ecline in sympathetic activity. Compared with elderly subjects from 81 to 100 years of age ultra-centenarians have significantly higher spec tral parasympathetic indexes. Parasympathetic predominance may be the neuroautonomic feature that helps to protect ultra-centenarians agains t cardiovascular disease. (C) 1998 Elsevier Science Ireland Ltd.