双腔心脏起搏时房室延迟对左室充盈动力学的影响

①目的　探讨双腔心脏起搏时房室延迟对左室充盈动力学的影响。②方法　对 19例患有完全性房室传导阻滞并植入永久性双腔心脏起搏器的病人 (起搏频率为 70min-1,房室延迟分别程控在 70ms,15 0ms和2 30ms) ,应用脉冲多普勒记录不同房室延迟时的二尖瓣口和主动脉的血流频谱。测量左室舒张期充盈时间、舒张早期峰值充盈速度、舒张晚期峰值充盈速度、舒张早期和舒张晚期峰值充盈速度的比值、二尖瓣舒张期血流速度时间积分和主动脉收缩期血流速度时间积分。③结果　随着房室延迟的增加 ,左室舒张期充盈时间变短 (F =2 7.9,P <0 .0 0 0 1) ,舒张早期峰值充盈速度降低 (F =4 .8,P <0 .0 5 ) ,舒张晚期峰值充盈速度增加 (F =5 .0 ,P <0 .0 5 ) ,舒张早期和舒张晚期峰值充盈速度的比值减小 (F =11.1,P <0 .0 0 0 1)。舒张期二尖瓣口血流速度时间积分和收缩期左室流出道血流速度时间积分在房室延迟 15 0ms时最大 (F =8.0 ,5 .5 ,P <0 .0 1)。④结论　双腔心脏起搏时左室舒张期充盈模式随房室延迟的不同而变化 ,多普勒超声对左室充盈模式变化的评估有助于获取双腔心脏起搏的最佳的血流动力学效应。

IMPACT OF ATRIOVENTRICULAR DELAY ON LEFT VENTRICULAR FILLING DYNAMICS DURING DDD PACING

Objective To evaluate the impact of the atrioventricular delay on the left ventricular filling dynamics during DDD pacing. Methods In 19 patients with complete atrioventricular block and DDD pacemakers, the atrioventricular delay was programmed at 70, 150 and 230 ms respectively, at a fixed rate of 70 min -1 ; the transmitral flow and aortic flow was obtained by pulsed Doppler echocardiography. The diastolic filling time, early diastolic transmitral peak flow velocity, late diastolic transmitral peak flow velocity, ratio of early diastolic transmitral peak flow velocity and atediastolic transmitral peak flow velocity, velocity time integral of transmitral flow and left ventricular outflow tract flow were measured. Results As the atrioventricular delay increased, the diastolic filling time ( F=27.9, P <0.0001), early diastolic transmitral peak flow velocity ( F=4.8, P <0.05) and ratio of early diastolic transmitral peak flow velocity and late diastolic transmitral peak flow velocity ( F=11.1, P <0.000 1) decreased significantly while the late diastolic transmitral peak flow velocity increased ( F=5.0, P <0.05). The velocity time integral of mitral flow and aortic flow ( F=8.0, 5.5, P <0.01) reached a maximum at the intermediate atrioventricular delay of 150 ms. Conclusion The transmitral filling pattern changes with different atrioventricular delay, which is of great value in optimizing the hemodynamic performance of the DDD pacemaker.