胎儿完全性房室传导阻滞宫内经静脉心脏起搏治疗的研究

Intrauterine Transvenous Cardiac Pacing for Fetal Complete Heart Block

为探讨胎儿完全房室传导阻滞宫内起搏治疗的可能性，本文采用6例羊胎作为研究对象，通过开腹剖宫的方式，对羊胎实行了经静脉右心室心内膜起搏，测定了三种情况下右心室输出量并对三尖瓣关闭不全的程度作了半定量测定，6例羊胎经静脉起搏电极的插入均顺利完成，右心室输出量测定结果如下：起搏电极前端留置在上腔静脉时（基准值）：107．0±13．3ml·kg－1·min；起搏电极前端经三尖瓣插入右心室后，右心输出量减少到73．8±175ml·kg－1·min（P＜0．05）；以200／分的频率右心室起搏后，右心输出量为78．3±23．6ml·kg－1·min；三尖瓣反流的半定量测定（三尖瓣反流信号／右房面积）：起搏电极前端在上腔静脉留置时（基准值），三尖辩反流信号右房之比为0．13±0．047；起搏电极前端经三尖瓣插入右室后为0．16±0．089；以200／分频率右心室起搏时，该比值为0．16±0．089。三种情况下，三尖瓣反流的程度无明显差别（P＞0．05）。本文结果表明，通过手术的方式给胎儿安植心脏起搏器是完全可行的。

To evaluate the feasibililty of intrauterine transvenous cardiac pacing,the right ventricular output was measured during pacing in six fetal lambs. Under maternal anesthesia,the uterus was opend,and under local anesthesia, the pacing lead was inserted via the fetal left internal jugular vein. Right ventricle output was estimated using an Aloka SSD-730 ultrasound device,and tricuspid valve regurgitation was evaluated with an Aloka SSD-880 using the transuterine approach. The ultrasonic right ventricular cardiac output was measured under three differnet conditions: (1)with the tip of pacing lead in the superior vena cava (control); (2)with the tip of the pacing lead in the right ventricle, and (3) with pacing at 200 beats/min. The right ventricular output decreased when the pacing lead was inserted into the right ventricle,as well as during pacing at 200 beats/min (107±13. 2 ml·kg-1·min; 73. 8± 17. 5 ml·kg-1/min; 78. 3±23. 6 ml·kg-1·min ). Tricuspid regurgitation did not change under any of the conditions tested. Intrauterine transvenous cardiac pacing was successfully achived. Insertion of the pacing lead into the right ventricle decreased the ventricular output without increasing tricuspid valve regurgitation.