The Normal Heart Rate Response to Treadmill Exercise

Background: Exercise stress testing is a routine method for evaluating the cardiovascular system. Heart rate (HR) increases with the sympathetic stimulation of exertion. The “normal” chronotropic change with exercise is often described, but not well documented. Methods: Consecutive patients presenting for “open access” Bruce Protocol stress echocardiography at HeartCare Partners testing facilities were enrolled. Patients having Dobutamine stress echocardiography, positive tests, pacemakers, atrial fibrillation, arrhythmia during stress, or on heart rate slowing medications (beta blockers, diltiazem, verapamil, digoxin, amiodarone, etc) were excluded. HR and blood pressure (BP) were recorded on standing at rest, and at the end of each stage of the Bruce Protocol, as well as the peak HR and BP, and then at 1 minute, 3 minutes and at 5 minutes into recovery. Results: Data from 206 patients were analysed (30% female). The mean age was 62 years. Patients exercised to an average 95% of maximum predicted HR and 10.9 METs. BP rose from 128/78 to 178/79mmHg. HR rose from an average 70bpm to a maximum of 152bpm, and back to 88bpm at test end. Conclusions: These data show the average (“normal”) heart rate responses to Bruce Protocol treadmill exercise in a contemporary setting.