钾通道开放剂尼可地尔对冠心病Warm-up现象及HRR的影响

Effect of a KATP channel opener nicorandil on Warm-up phenomenon and HRR

目的观察钾通道开放剂尼可地尔对冠心病Warm-up现象及患者反复运动后心率恢复（HRR）的影响。方法选择运动试验阳性以及经冠脉造影证实至少单支冠脉狭窄程度在70%~90%的慢性稳定型心绞痛患者75例。根据干预药物不同分为对照组（常规治疗）、尼可地尔组（常规治疗＋尼可地尔口服5 mg,3次/d）及单硝酸异山梨酯组（常规治疗＋单硝酸异山梨酯口服20 mg,2次/d）,各25例。各组均服药6个月以上。通过间隔15 min的连续两次运动试验（EX1与EX2）来观察各组缺血阈值（ST段压低0.1 m V时心率血压乘积即RPP值）、出现ST段压低0.1 m V时间（T-STD）、ST段压低的最大值（STDmax）、ST段恢复压低0.05 m V时间、总运动时间（ED）等反映心电图缺血情况的指标以及HRR的变化。结果 3组前后两次运动相比,EX2各指标均较EX1有明显改善（P均〈0.05）;单硝酸异山梨酯组仅STDmax高于对照组（P〈0.05）;尼可地尔组在RPP、T-STD、ST段恢复压低0.05m V时间、STDmax方面均明显优于对照组（P均〈0.01）和单硝酸异山梨酯组（P〈0.05或〈0.01）;尼可地尔组EX1后与EX2后HRR比较,P〈0.01,与对照组比较,P〈0.05。结论尼可地尔可促进冠心病Warm-up现象的发生,钾通道可能作为重要机制参与其中;同时尼可地尔有利于HRR。

Objective To investigate the effects of nicorandil which is a KATP channel opener on the warm-up phenomenon and the changes of heart rate recovery（ HRR） after sequential exercise test in patients with coronary artery disease.Methods Seventy-five patients with chronic stable angina who had positive exercise and were angiographically proved that the stenosis degree was 70-90% in at least one major branch were selected. They were divided into the control group with conventional treatment（ 25cases）,nicorandil group which was treated by the conventional treatment ＋ 5 mg nicorandil,three times a day（ 25cases） and the isosorbide mononitrate group which was treated by the conventional treatment ＋ 20 mg isosorbide mononitrate,twice a day（ 25cases）. All of them underwent two cycles of exercise tests（ EX1 and EX2） with interval of15 min. We observed the ischaemic threshold values（ the corresponding heart-rate systolic blood pressure,RPP）,the time of reducing 0. 1 m V ST-segment depression（ T-STD）,maximum STD（ STD max）,the recovery time to 0. 05 m V ST-segment depression,whole exercise duration（ ED） and the changes of HRR within and between the three groups. Results When we compared EX1 and EX2 among these three groups,each index of EX2 was improved as compared with that of EX1（ P〈0. 05）. Compared with the control group,only STDmax was improved better in the isosorbide mononitrate group（ P〈0. 05）.The changes of RPP,T-STD,the recovery time to 0. 05 m V ST depression and STDmax in the nicorandil group were better than those of the control group and the isosorbide mononitrate group（ P〈0. 05 or P〈0. 01）. There was significant difference in HRR between EX1 and EX2（ P〈0. 01）,as well as between the nicorandil group and the control group（ P〈0. 05）. Conclusions Nicorandil promotes the occurrence of the warm-up phenomenon,and KATP channel may be as an important mechanism involved in the warm-up phenomenon. Meanwhile,nicorandil is beneficial to HRR.