Ritchie Rebecca H, Zeitz Christopher J, Wuttke Ronald D, Hii John T Y, Horowitz John D
Cardiology Unit, The Queen Elizabeth Hospital, University of Adelaide, Adelaide, Australia.
J Am Coll Cardiol. 2006 Sep 19;48(6):1234-41. doi: 10.1016/j.jacc.2006.04.092. Epub 2006 Aug 28.
This study sought to compare the influence of changes in systolic interval on the negative inotropic effects of metoprolol, sotalol, and verapamil in patients with ischemic heart disease.
The long-term symptomatic and prognostic effects of antiarrhythmic agents are not easily predicted on the basis of acute hemodynamic actions at rest, but may be unmasked during tachycardia. However, this has not been studied extensively in vivo.
The force-interval relationship of the intact human left ventricle was examined before and 10 min after intravenous bolus administration of the negatively inotropic agents metoprolol, sotalol, or verapamil in patients undergoing diagnostic cardiac catheterization.
All three drugs similarly reduced maximal rate of increase of left ventricular pressures (LV+dP/dt(max)) by approximately 10%, but diversely modified the force-interval relationship. The parameter c (the reduction in LV+dP/dt(max) of a fixed premature stimulus on mechanical restitution) was significantly reduced by metoprolol (by 9+/- 4%, p < 0.05), was increased by verapamil (by 6 +/- 2%, p < 0.05), and was not significantly changed by sotalol. Similarly, metoprolol had a minimal effect on the extent of frequency potentiation, whereas sotalol and verapamil attenuated frequency potentiation (the relative response to 10 s of rapid pacing was 1.19 +/- 0.58-fold, 0.07 +/- 0.35-fold, and 0.03 +/- 0.17-fold of the baseline response after 10 min of metoprolol, sotalol, or verapamil, respectively).
These results show that the negative inotropic effects of metoprolol are attenuated and those of verapamil are accentuated at short cycle lengths; sotalol is intermediate between the two. These properties may contribute to the relative safety of these agents in patients prone to hemodynamic deterioration during sustained tachycardia.
本研究旨在比较收缩期间期变化对缺血性心脏病患者美托洛尔、索他洛尔和维拉帕米负性肌力作用的影响。
抗心律失常药物的长期症状性和预后作用不易根据静息时的急性血流动力学作用来预测，但在心动过速期间可能会显现出来。然而，这在体内尚未得到广泛研究。
在接受诊断性心导管检查的患者中，静脉推注负性肌力药物美托洛尔、索他洛尔或维拉帕米前及给药10分钟后，检测完整人左心室的力-间期关系。
所有三种药物均使左心室压力最大上升速率（LV + dP/dt(max)）类似地降低约10%，但对力-间期关系的改变各不相同。参数c（固定早搏刺激对机械恢复时LV + dP/dt(max)的降低）美托洛尔使其显著降低（降低9±4%，p < 0.05），维拉帕米使其升高（升高6±2%，p < 0.05），索他洛尔使其无显著变化。同样，美托洛尔对频率增强程度影响最小，而索他洛尔和维拉帕米减弱频率增强（美托洛尔、索他洛尔或维拉帕米给药10分钟后，对10秒快速起搏的相对反应分别为基线反应的1.19±0.58倍、0.07±0.35倍和0.03±0.17倍）。
这些结果表明，在短周期长度时，美托洛尔的负性肌力作用减弱，维拉帕米的负性肌力作用增强；索他洛尔介于两者之间。这些特性可能有助于这些药物在持续心动过速期间易发生血流动力学恶化的患者中的相对安全性。
