Introduction: Autonomic heart rate (HR) control evaluated by means of HR variability measures has been widely accepted as important information of cardiovascular function being a marker of sudden death. Methods: Polysomnography was performed in 405 CAD pts (mean age 60.7 yr.) pts, including 200 pts with CHF (mean age 63.4 yr.). Sleep apnea syndrome (SAS) was observed in 46 pts (mean age 64.2 yr...