Department of Internal Medicine II, Division of Cardiology, Medical University of Vienna, Austria.
Am J Cardiol. 2012 Jan 15;109(2):169-73. doi: 10.1016/j.amjcard.2011.08.025. Epub 2011 Oct 18.
Several studies have demonstrated the correlation of heart rate (HR) and image quality in coronary computed tomography angiography. Beta-blocker administration is critical because of its negative inotropic effect. Ivabradine is a selective HR-lowering agent that exclusively inhibits the I(f) current in sinoatrial node cells without having any effect on cardiac contractility or atrioventricular conduction. A total of 120 patients were randomized to oral premedication with ivabradine 15 mg or metoprolol 50 mg. HR and blood pressure (BP) were measured before the administration of premedication and immediately before coronary computed tomographic angiography. The mean time between premedication administration and follow-up was 108 ± 21.5 minutes for ivabradine and 110 ± 22.2 minutes for metoprolol (p = NS). When comparing groups, there were no significant differences in reduction of HR (-11.83 ± 8.6 vs -13.20 ± 7.8 beats/min, p = NS) and diastolic BP (-5.05 ± 14.2 mm Hg vs -4.08 ± 10.8 mm Hg, p = NS), whereas the decrease of systolic BP was significantly lower in patients who received ivabradine compared to those in the metoprolol group (-3.95 ± 13.6 vs -13.65 ± 17.3 mm Hg, p <0.001). In the subgroup of patients who were receiving long-term β-blocker therapy, significantly stronger HR reduction was achieved with ivabradine (-13.19 ± 5.4 vs -10.04 ± 6.0 beats/min, p <0.05), while the decrease in systolic BP was less (-2.00 ± 13.6 vs -15.04 ± 20.8 mm Hg, p <0.05) compared to metoprolol. In conclusion, ivabradine decreases HR before coronary computed tomographic angiography sufficiently, with significantly less depression of systolic BP compared to metoprolol.
几项研究已经证明了心率（HR）和冠状动脉计算机断层血管造影术的图像质量之间的相关性。由于其负性肌力作用，给予β受体阻滞剂至关重要。伊伐布雷定是一种选择性 HR 降低剂，它仅抑制窦房结细胞中的 I(f)电流，而对心肌收缩力或房室传导没有任何影响。共有 120 名患者被随机分为口服伊伐布雷定 15mg 或美托洛尔 50mg 进行预给药。在给予预给药前和进行冠状动脉计算机断层血管造影术之前测量 HR 和血压（BP）。伊伐布雷定和美托洛尔的预给药和随访之间的平均时间分别为 108±21.5 分钟和 110±22.2 分钟（p=NS）。比较两组时，HR 下降（-11.83±8.6 与-13.20±7.8 次/分，p=NS）和舒张压下降（-5.05±14.2mmHg 与-4.08±10.8mmHg，p=NS）无显著差异，而接受伊伐布雷定的患者收缩压下降明显低于美托洛尔组（-3.95±13.6 与-13.65±17.3mmHg，p<0.001）。在接受长期β受体阻滞剂治疗的患者亚组中，伊伐布雷定可显著降低 HR（-13.19±5.4 与-10.04±6.0 次/分，p<0.05），而收缩压下降较少（-2.00±13.6 与-15.04±20.8mmHg，p<0.05）与美托洛尔相比。总之，伊伐布雷定在冠状动脉计算机断层血管造影术之前充分降低 HR，与美托洛尔相比，收缩压的降低明显较小。
