Wennerblom B, Lurje L, Westberg S, Johansson M, Lomsky M, Vahisalo R, Hjalmarson A
Division of Cardiology, Sahlgrenska Hospital, Göteborg, Sweden.
Cardiology. 1998;89(2):87-93. doi: 10.1159/000006762.
Beta-blockers reduce sympathetic tone, increase vagal tone and improve prognosis in ischaemic heart disease. Nitroglycerin, being a vasodilator, may theoretically have an opposite effect and worsen the prognosis. The purpose of the present study was to analyse heart rate variability (HRV), which reflects autonomic tone, in angina patients on isosorbide-5-mononitrate (IS-5-MN) and/or metoprolol.
Thirty-two patients (32-81 years old), with recently developed angina (median duration: 3 months), showing no other disease and on no drugs, were Holter-monitored 24-48 h at baseline and after 4-5 days on IS-5-MN (mean daily dose: 33 mg), on metoprolol (mean daily dose: 184 mg) and on the combined treatment. Recordings were analysed on the Marquette Series 8000 Holter scanner. Both IS-5-MN and metoprolol significantly reduced myocardial ischaemia (ST integral) and ventricular tachycardias. Metoprolol induced significant changes in the following parameters (baseline versus metoprolol): high-frequency peak 9 +/- 4 versus 11 +/- 4 ms (p < 0.001), low-to-high frequency ratio 2.5 +/- 0.6 versus 1.9 +/- 0.6 (p < 0.0001), root mean square of RR interval difference 23 +/- 7 versus 31 +/- 9 ms (p < 0.0001), RR intervals differing more than 50 ms from the preceding one 4.8 +/- 3.9 versus 10.0 +/- 7.0% (p < 0.0001), mean of all 5-min standard deviations 50 +/- 12 versus 56 +/- 11 ms (p < 0.001) and mean RR interval 819 +/- 90 versus 1,019 +/- 120 ms (p < 0.00001). The combined treatment caused approximately the same HRV changes as metoprolol alone. IS-5-MN had no significant effect on any HRV parameter, neither alone nor in combination with metoprolol.
A clinically effective dose of metoprolol had potentially positive effects on HRV with increase in vagal and decrease in sympathetic tone while IS-5-MN had no effect on HRV, neither positive nor negative, neither alone nor in combination with metoprolol.
β受体阻滞剂可降低交感神经张力，增加迷走神经张力，并改善缺血性心脏病的预后。硝酸甘油作为一种血管扩张剂，理论上可能产生相反的效果并使预后恶化。本研究的目的是分析服用5-单硝酸异山梨酯（IS-5-MN）和/或美托洛尔的心绞痛患者的心率变异性（HRV），HRV反映自主神经张力。
32例患者（年龄32 - 81岁），近期发生心绞痛（中位病程：3个月），无其他疾病且未服用任何药物，在基线时以及服用IS-5-MN（平均日剂量：33 mg）、美托洛尔（平均日剂量：184 mg）及联合治疗4 - 5天后进行24 - 48小时的动态心电图监测。记录数据在Marquette系列8000动态心电图扫描仪上进行分析。IS-5-MN和美托洛尔均显著降低心肌缺血（ST段积分）和室性心动过速。美托洛尔使以下参数发生显著变化（基线值与美托洛尔治疗后）：高频峰值9±4毫秒对11±4毫秒（p < 0.001），低频与高频比值2.5±0.6对1.9±0.6（p < 0.0001），RR间期差值的均方根23±7毫秒对31±9毫秒（p < 0.0001），与前一个RR间期相差超过50毫秒的RR间期占比4.8±3.9%对10.0±7.0%（p < 0.0001），所有5分钟标准差的平均值50±12毫秒对56±11毫秒（p < 0.001），平均RR间期819±90毫秒对1019±120毫秒（p < 0.0000）。联合治疗引起的HRV变化与单独使用美托洛尔大致相同。IS-5-MN对任何HRV参数均无显著影响，无论是单独使用还是与美托洛尔联合使用。
临床有效剂量的美托洛尔对HRV具有潜在的积极影响，可增加迷走神经张力并降低交感神经张力，而IS-5-MN对HRV无影响，无论是单独使用还是与美托洛尔联合使用，既无正向影响也无负向影响。
