The normal range and determinants of the intrinsic heart rate in man

Abstract

Normal standards for the intrinsic heart rate (IHR) were measured in 432 healthy adult subjects aged 16 to 70 years. At rest, with normal body temperature, the IHR was highly reproducible. In different subjects, age was the only important determinant. Differences in IHR between individuals may correspond to differences in functional capacity of the myocardium, whether determined genetically, by age, or by disease.