title: The significance of data obtained from indirect methods for evaluation of sinus node function.
mesh_terms: D000328:Adult; D000368:Aged; D001283:Atrioventricular Node / Q000502:physiology*; D004562:Electrocardiography; D005260:Female; D006329:Heart Conduction System / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged