Determinants of heart rate recovery in patients with suspected coronary artery disease.

BACKGROUND Heart rate recovery after exercise is an independent prognostic indicator for cardiovascular and all-cause mortality. The purpose of this study was to clarify the clinical determinants of heart rate recovery. METHODS AND RESULTS We examined 114 consecutive male patients who underwent exercise myocardial perfusion single-photon emission computed tomography and echocardiography for the evaluation of suspected coronary artery disease. Heart rate recovery was obtained from the subtraction of heart rate in the first minute of recovery after exercise from maximal heart rate during exercise. Abnormal heart rate recovery was present in 50 patients (43.9%). Patients with abnormal heat rate recovery were more likely to have diabetes mellitus. Patients with abnormal heart rate recovery had a higher heart rate at rest than those with normal heart rate recovery (77.5 +/- 13.6 vs. 72.3 +/- 12.5 (bpm), p<0.05). However, no differences in left ventricular geometry investigated with echocardiography were observed between patients with normal and abnormal heart rate recovery. Furthermore, there was no difference in various scintigraphic variables between patients with normal and abnormal heart rate recovery. A stepwise multivariate analysis showed that heart rate at rest and diabetes mellitus were independent predictor of heart rate recovery (p<0.05). CONCLUSION Our results suggested that heart rate recovery is associated with clinical factors related to the cardiac autonomic function such as diabetes mellitus and heart rate at rest, but not with other ones such as left ventricular geometry and myocardial ischemia.