Effects of metoprolol on heart rate variability in patients with coronary heart disease

ObjectiveTo evaluate the effect of metoprolol on heart rate variability(HRV) in patients with coronary heart disease(CHD).MethodsNinety-eight patients with CHD were randomly divided into control group(n=49) and metoprolol group(n=49).The patients in control group were treated with nitrate,angiotensin-converting enzyme inhibitor,calcium antagonist,aspirin and low molecular heparin according to patients′ condition.Based on this,the patients in metoprolol group were treated with metoprolol 25 mg orally at morning and night,two times per day for two weeks.The 24 h dynamic electrocardiogram was recorded pre-and post-treatment,and the changes of indexes of HRV were observed.ResultsThere was no statistical significance in HRV between two groups before treatment(P0.05).The HRV in two groups improved significantly posttreatment compared with pretreatment(P0.01),the improvement of HRV was more in metoprolol group than that in control group(P0.01).There was no statistical significance in adverse reaction between two groups(P0.05).ConclusionMetoprolol could significantly improve HRV in patients with CHD.