Objective To evaluate the efficacy of sequential cardiac resynchronization therapy ( CRT ) with individualized interventricular delay( VVD )optimization by echocardiography and tissue Doppler imaging( TDI ). Methods Twenty-six patients with severe heart failure were included in this study. Conventional echocardiography and TDI were performed on the day before and after biventricular pacemaker implantation. The echocardiography examinations were carried out during the procedures of simultaneous and sequential pacing. The first step was to determine the optimal atrioventricuW AV ) delay by using the mitral valve velocity-time integral( VTIMv ). Then the optimal WD was obtained based on the aortic velocity-time integral( VTIAo )and the index of systolic dyssynchrony( SDI ). Results Pre-activation of the left ventricular lead was achieved in all patients with the optimal WDs ranging from 4 ms to 40 ms. Compared with simultaneous biventricular pacing, the VTIAo and myocardial performance index( MPI ) were significantly improved by individually optimized sequential pacing. The VTIAo and MPI for optimized sequential pacing were( 22. 3 ± 4. 5 )cm and( 0. 78 ± 0. 18 ), while those for simultaneous pacing were( 20. 8 ± 4. 9 )cm and ( 0. 86 ±0. 17 )respectively. There was a significant difference between them( t = - 5. 055,3. 217, all P < 0. 05 ). An additional improvement of inter-and intra-ventricular dyssynchrony was also obtained by sequential pacing. Compared with simultaneous pacing, interventricular mechanical delay( IVMD )[ ( - 24 ± 19 )ms vs( - 32 ± 19 )ms ], SDI[ ( 12.1 ± 2.9 )vs( 14.3 ± 2.6 ) ]and post systolic shortening( PSS)[ ( 30.8 ± 16.7 )% vs ( 38. 3 ± 16.3 )% ] were significantly reduced by individually optimized sequential pacing( t = - 3. 370,4. 592, 3. 250,all P <0. 01 ). Conclusions The individual assessment of WD improves myocardial efficiency and acute invasive hemodynamic parameters over the default settings. Echocardiography and TDI play an important role in the determination of optimal parameters for CRT.%目的 应用常规超声心动图及组织多普勒定量评价个体优化设定室间(VV)间期的心脏再同步化起搏治疗效果.方法 26例经再同步化起搏治疗的重度充血性心力衰竭患者,三腔起搏器安置术后先采用起搏器默认参数,术后1周内在超声指导下进行个体起搏参数优化.优化时,先根据二尖瓣前向血流频谱形态及速度时间积分(VTIMv)得出最佳房室(AV)间期后,再根据主动脉流速时间积分(VTIAo)及组织多普勒测量得出的收缩不同步指数(SDI)判定双室顺序起搏时个体最佳VV间期.结果 26例重度充血性心力衰竭患者经个体优化后,最佳VV间期均为左心室提前起搏,范围在4～40 ms,个体差异明显.个体优化设定VV间期后VTIAo和做功指数(MPI)测值分别为(22.3±4.5)cm、(0.78±0.18),双室同步起搏时的测值分别为(20.8±4.9)cm、(0.86±0.17),两者比较差异有统计学意义(t=-5.055、3.217,P均＜0.05).VTIAo进一步增大,MPI则进一步减小;经个体优化最佳VV间期后室间机械延迟(IVMD)、SDI、收缩后缩短现象(PSS)测值分别为(-24±19)ms、(12.1±2.9)、(30.8±16.7)%,双室同步起搏时的测值分别为(-32±19)ms、(14.3±2.6)、(38.3±16.3)%,两者比较差异有统计学意义(t=-3.370、4.592、3.250,P均＜0.01).心室内及心室间同步性进一步改善,IVMD、SDI、PSS更加减小.结论 经个体优化设定心室起搏顺序后,心脏再同步化治疗效果更好,心室的收缩协调性得到了最大程度的改善.常规超声心动图,尤其是频谱多普勒,在个体优化中发挥主导作用,组织多普勒能够定量评价心室收缩同步性,阐释发生血流动力学变化的机械运动机制,在同步化治疗过程中发挥的作用不可替代.
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