DECREASED HEART-PERIOD VARIABILITY IN PATIENTS WITH PANIC DISORDER - A STUDY OF HOLTER ECG RECORDS

This study investigated cardiac autonomic function in patients with pa nic disorder and normal controls using Holter ECG records. A decrease in ultra-low frequency power (<0.0033 Hz) is known to be associated wi th an increased risk for cardiovascular mortality in humans. Twenty-fo ur-hour ECG was recorded in 29 patients with panic disorder and 23 nor mal controls using Holter records. Data for 20 h and also 20 000 s of awake and 20 000 s of sleep periods were analyzed using spectral analy sis to quantify absolute and relative heart-period variability in ultr a low (ULF: <0.0033 Hz), very low (VLF: 0.0033-0.04 Hz), low (LF: 0.04 -0.15 Hz) and high (HF: 0.15-0.5 Hz) frequency bands. The patients wit h panic disorder had significantly lower total and absolute ULF power, which was more pronounced during sleep. The patients also had signifi cantly lower relative ULF power and significantly higher relative LF p ower during sleep. There was a significant increase of relative LF pow er from awake to sleep period only in the patient group. The decrease in total and ULF power may increase the risk of mortality and sudden a rrhythmic death in patients with panic disorder if they experience a c ardiac event. The higher relative LF power during sleep also suggests a possible higher sympathetic drive in the patients during sleep. (C) 1998 Elsevier Science Ireland Ltd.