心腔内超声评价希氏束起搏心脏血流动力学和解剖结构重构

Cardiac hemodynamic and anatomical remodeling during His bundle pacing:an intracardiac echocardiographic study

目的 采用单一的心腔内超声心动图和组织多普勒显像技术检测和评价直接希氏束起搏诱导的心室激动顺序、心脏解剖结构和血流动力学重构。方法 六只急性闭胸直接希氏束起搏狗模型。采用美国Medtronic导向引导鞘管和主动螺旋电极 ,在心腔内超声心动图和组织多普勒显像技术引导下将起搏电极分别置放于希氏束 (n =6)和右室心尖 (n =6)。所有部位的起搏频率均控制为 12 0次 /min。采用二维灰阶、血流频谱多普勒和组织多普勒技术 ,分别测量和计算心脏不同部位起搏时心室各房室和相连大血管解剖结构内径和容量、心肌的激动顺序和相关血流动力学参数 ,并进行不同起搏状态上述测量参数的配对统计比较。结果 希氏束起搏状态下 ,左心室壁内心肌的激动顺序、心脏主要解剖结构和血流动力学参数与窦性心律状态下相同参数比较无显著性差异 ;与右心室心尖起搏状态下相同参数比较有显著性差异。结论 单一的心腔内超声和组织多普勒技术能够有效地量化评价心脏起搏状态下的心脏解剖结构和血流动力学改变。与右心室心尖部起搏相比较 。

Objective His bundle pacing (HBP) has been proposed to improve cardiac function and hemodynamics. This study compares the hemodynamic performance of HBP to right ventricular apical pacing (RVA) and sinus rhythm. Methods In the acute tests of six anesthetized closed chest canines, a custom designed bipolar screw in lead was implanted using a steerable delivery catheter guided with intracardiac echocardiography (ICE) and tissue Doppler imaging (TDI). The bipolar leads were implanted near the His bundle (HBP) and in the right ventricular apex (RVA). A pacing rate of 120 bpm was used to compare HBP (VOO mode), RVA (VOO mode), and sinus rhythm (SR). Results QRS widths were as follows: SR = 59.7 + 5.3 m; HBP = 82.8 + 16.6 m; RVA = 106.3 + 18.4 m ( P <0.05 for all comparisons). HBP included direct His pacing ( n =1) and His + ventricular septal capture ( n =5). Cardiac function, hemodynamics, and sequence of ventricular excitation were analyzed using ICE and TDI. During HBP, a similar pattern of left ventricular excitation and hemodynamic function was seen as in sinus rhythm. The HBP data are similar to SR and significantly different than RVA pacing (Table 1). Conclusion HBP significantly improves cardiac performance when compared to RVA pacing. The hemodynamic improvements could be evaluated quantitatively and efficiently using ICE and TDI.