通过分析脉搏波形研究硝酸甘油对血管的作用

Effect of glyceryl trinitrate on blood vessel measured by pulse wave analysis

目的 用无创脉搏波分析方法揭示硝酸甘油 (GTN)对不同特性血管的剂量依赖效应。方法 46名志愿者随机给予安慰剂或不同剂量的缓释GTN贴剂 ( 0 1～ 0 6mg h) ,记录桡动脉脉搏波 ,并与传统的袖带血压计测量结果对照。中心动脉脉搏波通过已验证的转换函数从桡动脉脉搏波实时生成。结果 除了 2个最大剂量组的肱动脉收缩压下降外 ,心率及肱动脉血压没有明显变化。通过脉搏波分析获得的中心动脉收缩压、反射波增压、积分平均压和左室射血分数均有一致的剂量依赖的改变。结论 脉搏波分析比传统袖带血压计有优势 ,揭示了很低剂量的GTN影响血流动力学的证据 ,其机制是传输动脉扩张 ,波反射降低 ,更大剂量的GTN可进一步引起静脉及阻力小动脉扩张。

Objective To show dose-dependent effect of glyceryl trinitrate (GTN) on conduit arteries,resistive arterioles,and capacitive veins using noninvasive pulse wave analysis. Methods Effect of GTN in patch form, delivering 0.1-0.6 mg/h was assessed over a five-hour period in 46 fasting, recumbent patients through analysis of the radial pulse waveform, compared with conventional cuff sphygmomanometry. Ascending aortic pressure waveforms were generated from the radial waves, using a validated generalized transfer function. Results There were no consistent changes in heart rate or in brachial pressure values, except for decrease in systolic pressure at the highest dose of GTN. In contrast, there were consistent dose-dependent changes in estimated ascending aortic pressure augmentation, systolic pressure, integrated mean pressure and left ventricular ejection duration. Conduit artery dilation was inferred from the fall in augmented and systolic aortic pressure at the lowest to highest dose. Venous dilation was inferred from decrease in left ventricular ejection duration which occurred at the second lowest to highest dose. Arteriolar dilation was inferred from reduction in integrated mean aortic pressure at the highest dose. Conclusion In comparison with conventional cuff sphygmomanometry, there were some potential advantages using analysis of the arterial pulse waveform, which showed evidence of hemodynamic effect at very low dose, and attributable to dilation of conduit arteries with reduction in wave reflection. Venous and arteriolar dilation appears to require higner dosage.