RESUMEN
<p><b>OBJECTIVE</b>To evaluate the effect of Xinkeshu Tablet (XKS) on heart rate variability (HRV) in patients with coronary heart disease (CHD).</p><p><b>METHODS</b>Sixty patients with their diagnosis of CHD confirmed by coronary angiography were randomized into two groups equally. Besides the conventional treatment for CHD, XKS and Metoprolol were given respectively to patients in the treated group and the control group for 8 weeks. Symptoms and 24 h dynamic ECG were observed before and after treatment.</p><p><b>RESULTS</b>Episode of angina pectoris decreased obviously in both groups after treatment, from 8.8 +/- 3.2 times per week (the same hereafter) to 4.4 +/- 2.1 in the treated group (P<0.05), and from 8.4 +/- 3.1 to 3.9 +/- 2.0 in the control group (P <0.05). HRV analysis showed that after treatment the average heart rate lowered from 85.44 +/- 2.89 beat/min to 77.32 +/- 2.17 beat/min in the treated group and from 83.80 +/- 4.30 beat/min to 76.70 +/- 2.93 beat/min in the control group (both P < 0.05), showing no significant difference in extent of lowering between groups (P > 0.05). The time-domain indexes elevated in both groups, showing no statistical difference between groups (P >0.05). As for the frequency-domain indexes, low frequency (LF), high frequency (HF) and total power raised, while LF/HF and very low frequency lowered in both groups, but the changes were more significant in the treated group (P <0.05).</p><p><b>CONCLUSION</b>XKS could improve HRV in patients of CHD and reduce the episode of angina pectoris in them.</p>