Comparison of the Changes in Heart Rate Recovery Before and after Cardiac Rehabilitation in Patients Undergoing the Coronary Artery Bypass Surgery Based on the Risk Factors for Heart Failure, Diabetes and Smoking

Coronary artery bypass surgery is still a selective treatment for patients with a severe coronary artery disease all over the world. It has been tried to perform actions before and after the surgery to increase the survival rate and the quality of life of the patients. The aim of this study was to compare heart rate recovery changes before and after cardiac rehabilitation in these patients.
This clinical trial study was conducted on 70 patients with coronary artery bypass surgery. For all patients, 12 rehabilitation sessions were considered. Before the beginning and after finishing the recovery and rehabilitation sessions, patients were evaluated using the exercise-stress test by the standard Bruce method and the amounts of heart rate recovery (HRR) were calculated before and after the sessions. Data were analyzed using descriptive statistics and paired t-test with the SPSS 19 software.
The mean HRR among the patients before the recovery was 21.01 ± 7.74 and after the recovery was 25.53 ± 7.62 (P = 0.000). The mean HRR among the patients with normal left ventricular (LV) function before the recovery was 22.33 ± 7.42 and after it was 25.17 ± 6.59. Also, the mean HRR in patients with mild LV dysfunction before the recovery was 20.23 ± 8.48 and after it was 24.85 ± 8.02 and the mean HRR in patients with moderate LV dysfunction before the recovery was 20.84 ± 3.87 and after it was 30.67 ± 8.41.
The results showed that the mean HRR after the recovery significantly increased compared to before the recovery.