POWER SPECTRUM OF THE QRS COMPLEX IN PATIENTS WITH PANIC DISORDER ANDNORMAL CONTROLS

We performed spectral analysis on the QRS complex of the electrocardio gram obtained using standard limb leads, sampled at 500 Hz with 12 bit precision in 20 normal subjects and 15 patients with panic disorder. We divided the frequency range of the QRS into two bands based on spec tral patterns before and after the postural challenge mid frequency (M F): 7.8-20 Hz; and high frequency (HF): 21-250 Hz. Postural change fro m supine to standing produced a significant increase in absolute (P = 0.003) and relative HF power (P = 0.00001). Patients with panic disord er had a significantly decreased QRS HF power (P = 0.003). The increas e in QRS HF power may have been due to the shortening of the QRS inter val in standing posture. The decreased QRS HF power in patients with p anic disorder should be further investigated due to the recent reports of an association of phobic anxiety and fatal coronary heart disease, and the possible association of decreased high frequency components o f QRS in myocardial infarction. (C) 1997 Elsevier Science Ireland Ltd.