P wave variations associated with change in heart rate, with sepcial reference to the site of impulse origin.
D000293:Adolescent; D000328:Adult; D001919:Bradycardia / Q000175:diagnosis; D004562:Electrocardiography; D005080:Exercise Test; D006329:Heart Conduction System / Q000502:physiology*; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012849:Sinoatrial Node / Q000502:physiology; D013610:Tachycardia / Q000175:diagnosis