The effect of cardiac rehabilitation on recovery of heart rate over one minute after exercise in patients with coronary artery bypass graft surgery

OBJECTIVE: To evaluate the effects of cardiac rehabilitation on the recovery of heart rate over 1 min after peak exercise of patients who received coronary artery bypass graft (CABG) surgery. DESIGN: Thirty subjects who received CABG surgery were randomly assigned to enter or not enter a cardiac rehabilitation exercise programme (cardiac rehabilitation n = 15; control group n = 15). SETTING: Outpatient cardiac rehabilitation centre in a national medical hospital. INTERVENTIONS: Patients assigned to the cardiac rehabilitation group received 36 sessions of the exercise programme, three times a week, with the intensity designed to achieve an individual 60-85% peak heart rate in cardiopulmonary exercise test. Patients assigned to the control group did not get further advice about a specific exercise programme. MAIN OUTCOME MEASURES: Resting heart rate and recovery of heart rate over 1 min after a peak exercise test at discharge and three months later were collected. The heart rates were analysed with computer-recorded electrocardiogram. RESULTS: At follow-up, the 15 patients in the cardiac rehabilitation group had a significantly lower resting heart rate (77.46+/-9.49 versus 92.31+/-10.18 bpm; p<0.001) and a significantly higher recovery of heart rate over 1 min (16.38+/-6.32 versus 11.38+4.81 bpm; p = 0.03) compared with the control group. There were also significant reductions in resting heart rates (cardiac rehabilitation p < 0.001; control p = 0.05) and improvements in recovery on heart rate over 1 min (cardiac rehabilitation p < 0.001; control p = 0.001) compared with baseline measurements in both the cardiac rehabilitation and control groups. CONCLUSION: Cardiac rehabilitation had a positive effect on the improvement of recovery on heart rate over 1 min in patients with coronary artery disease who received CABG surgery.