[Sinus node function in man. Statistical analysis].

The sinus function of 60 patients was studied by atrial stimulation at a fixed rate, and also at a rate linked with the preceding sinus cycle. These patients were divided into 3 groups according to the surface-recorded ECG; 10 had clear evidence of sinus dysfunction, 23 had an isolated sinus bradycardia, and 27 were considered as controls a their sinus rate was above 60/min., with a normal PR interval.