HEART-RATE ANALYSIS IN 24 PATIENTS TREATED WITH 150 MG AMITRIPTYLINE PER DAY

Twenty-four patients treated with 150 mg amitriptyline per day for an episode of major depression underwent a standardized heart rate analys is (HRA) before therapy and after 14 days. The battery of cardiovascul ar reflex tests included the determination of the coefficient of varia tion (CV) while resting and during deep respiration, a spectral analys is of heart rate, the heart rate response to standing, and the Valsalv a manoeuvre. The results of the initial HRA did not differ from a grou p of 24 normal control subjects matched for age and sex. On day 14 of treatment the patients showed significantly reduced values of heart ra te variability in all tests (P < 0.0001), probably due to the antichol inergic side effects of amitriptyline. Heart rate increased form 78.1 to 93.6 bpm on average (P < 0.0001). Abnormal CV at rest was registere d in 96% of the patients; during deep respiration 29% showed abnormal CV results. An abnormal spectral analysis was found in 100% of the cas es (low frequency peak: 42%, mid-frequency peak: 100%, high frequency peak: 79%). The heart rate response to standing was abnormal in 75% an d the Valsalva test in 33% of the cases. Eighty-eight percent of the p atients fulfilled the criteria of a cardiovascular autonomic neuropath y under the conditions of amitriptyline therapy. As yet, the consequen ces of these changes for the patients have not been sufficiently eluci dated.