[Effects of Verapamil and Metoprolol on heart rate variability in patients with coronary heart disease].

OBJECTIVE

To evaluate the effects of Verapamil and Metoprolol on improving heart rate variability(HRV) in patients with coronary heart disease (CHD).

METHODS

A total of 60 patients, who were diagnosed as CHD according to the results of coronary angiography, were enrolled. All patients were randomly divided into Verapamil group (n=30) and Metoprolol group (n=30). The patients in Verapamil group received Verapamil (480 mg/d) and the patients in Metoprolol group received Metoprolol (50 mg/d) for eight weeks. Office blood pressure, HRV, symptoms of angina Holter recording heart rates per minute and HRV for eight weeks were observed before and after treatment in both groups.

RESULTS

Both office blood pressures and the numbers of attacks of angina pectoris and symptoms all decreased obviously in the two groups after treatment. Blood pressures were reduced from 137.12/84.36 mm Hg to 131.80/77.68 mm Hg in Metoprolol group, and also reduced from 137.72/83.92 mm Hg to 129.56/78.76 mm Hg in Verapamil group (P>0.05, compared between the two groups). In both the Verapamil and Metoprolol groups, heart rates decreased, SDNN (standard deviation of all normal to normal RR intervals) and HRVTI (HRV indexes of time-domain) both increased significantly after treatment (P>0.05). And HRV indexes of low-frequency(LF), high-frequency (HF) and total power (TP) were increased obviously, while the low-to high-frequency ratio (LF/HF), very-low-frequency (VLF) were remarkably lower(P<0.05). Compared with Verapamil group, the changes of frequency-domain indexes in Metoprolol group were significant(P<0.05).

CONCLUSION

In patients with CHD, both Metoprolol and Verapamil can increase the HRV.