P-212: Long-term effects of medical therapy on autonomic control of heart rate in patients with congestive heart failure with or without hypertension

Since reduced heart rate variability (HRV) is known to be a predictor of prognosis of congestive heart failure, we examined long-term effects of conventional medical therapy on HRV in 314 patients with congestive heart failure (62±1 years, NYHA classification 1 to 4), consisting with dilated cardiomyopathy, coronary artery disease, or hypertensive heart disease. Patients were randomly assigned to beta-blocker, angiotensin converting enzyme (ACE) inhibitor, dihydropyridine derivatives, diltiazem, nitrate, or these combinations with or without digitalis and furosemide therapy. 48 patients were treated only by life style modification (LIFE). 24-hour ECG recordings were repeated before and after the therapy (mean duration: 76 weeks), and HF (0.15-0.4 Hz), TF(0.004-1 Hz) and LF (0.04-0.15 Hz) /HF ratio of HRV were calculated by maximum entropy method. Both HF and TF were significantly (p