Objective To evaluate the effect of meglumine cyclic adenosine (MAC) on heart rate variability (HRV) in aged-patients with coronary heart disease (CHD).MethodsSeventy six aged-patients with CHD were randomly divided into control group (n =36) and treatment group (n =40).The patients in control group were treated with nitrate,ozagrel,calcium antagonist,aspirin enteric-coated tablets,low molecular heparin,angiotensin-converting enzyme inhibitor ( ACEI ) or angiotensin receptor antagonist ( ARB ) and lipidlowering agents according to patients' conditions.Based on this,the patients in treatment group were treated with MAC 90 mg intravenous injection once a day for two weeks.The 24 h dynamic electrocardiogram was recorded.pre-ard post-treatment,and the changes of HRV indexes were observed.Results There was no statistical significance in HRV between the two groups before treatment ( P ＞ 0.05 ).However the HRV in two groups improved significantly after treatment ( P ＜0.01 ).The improvement of HRV was more significant in MAC group than that in control group (P ＜0.01 ).Conclusion MAC can significantly improve HRV in aged-patients with CHD.