Effect Of Valsartan On Chronotropic Incompetence In Hypertensive Patients Complicated With Type 2 Diabetes Mellitus

ObjectiveTo investigate the charact of chronotropic incompetence in hypertensive patients complicated with type 2 diabetes mellitus and the effect of valsartan on it.Subjects and Methods1.Subjects40 cases of hypertensive patients complicated with type 2 diabetes mellitus were treated with valsartan 80-160mg/d for 12 weeks,and to study the changer of chronotropic incompetence and compared with control group(40 cases) 2.Methods2.1 Treatment methodsOn the basis of anti-diabetic treatment plus valsartan 80mg/d,the dose is adjusted according to the level of blood pressure after tow weeks,Two weeks after the blood pressure＞140/9OmmHg,Valsartan will be increased to 160 mg/d;if Blood pressure do not reach normal blood pressure after four weeks, the daily dose were given valsartan 160 mg/d+hydrochlorothiazide tablets 12.5～25mg,Up to normal blood pressure,a total of 12 weeks of treatment.2.2 Outcomes measure and methodsAll patients were using the United States Merrill Lynch production Mortara Instrument treadmill exercise test inspection, Observing(?)movement in the maximal heart rate,Use formula CRI=Heart Rate Reserve/metabolism reserves×100%,HRR=(Maximum heart rateresting heart rate)/(220-age-resting heart rate)×100%(2)the diagnosis of chronotropic incompetence:①Movement of maximal heart rate(Max HR)not reach to maximal age-predicted heart rate(220-age)85%②Heart Variable Index(CRI)＜0.8③the ratio of heart rate reserve(HRR)＜80%Results The observe group before treatment was compared with the normal group,CRI＜0.8(24 cases)in observe group was significantly more than the normal group(one case)x~2=30.78,P=0.001;HRR＜0.8(23 cases)in observe group was significantly more than the normal group (one case),x~2=28.81,P=0.008;Below the target heart rate for the observe group were 17 case,three cases of the normal group,x ~2=3.98,P=0.042:Max HR(132±22)bpm,CRI(0.70±0.20),Increasing HR(45±19)bpm,Mets(5.22±2.17)in observe group was obviously lower than the normal group Max HR(160±17)bpm,CRI(1.22±0.24) Increasing HR(85±16)bpm,Mets(7.83±2.61),P＜0.05,with statistical significance.Then we compared the range of ST segment depression in the two groups,P=0.21,there was also significant diffrence.After treated with valsartan 80-160mg/d for 12 weeks,,the Max HR(144±18)bpm,CRI(0.81±0.21),Mets(6.34±2.38),Increasing HR(62±17)bpm was obviously increased,compared with before treatment,P＜0.05,with statistical significance.After treatment, the cases with CRI＜0.8 or HRR＜0.8 in observe group were reduced to 15 cases,P＜0.05,with statistical significance.The cases below the target heart rate was decreased from 17 cases to 8 cases,x~2=4.71, P=0.041,with statistical significance.Conclusion chronotropic incompetence is common in observe group, which maybe reflect the impaimment of cardiac autonomic regulation. Valsartan can lower the blood pressure,increase cardiac vagal activity and decrease sympathetic activity,which suggests that valsartan may reduce the arrhythmic mortality.