儿童置入频率适应性起搏器前后药物负荷左室收缩功能的研究

A study of drug stress left ventricular systolic function pre-and post-rate adaptive pacemaker implantation in children

目的 了解儿童完全性房室传导阻滞（ＣＡＶＢ）置入频率适应性起搏器前后左室收缩功能的变化。方法 对６ 例３～１２ 岁ＣＡＶＢ患儿，采用多巴酚丁胺负荷超声心动图技术测定起搏器置入术前及术后３～６ 月的左室短轴缩短率（ＦＳ）、射血分数（ＥＦ）、室壁增厚率（ＬＶＰＷＴ）、应变率（ＭＶＣＦＣ） 、每搏指数（ＳＩ） 及心排指数（ＣＩ），并与８ 例正常同龄儿童进行对比分析。结果 术前ＦＳ及ＥＦ均随药物浓度增加而稍增大，但与对照组比较无显著差异，Ｐ 均＞ ０－０５；ＬＶＰＷＴ、ＭＶＣＦＣ及ＳＩ于静息状态及低药物浓度时明显高于对照组，Ｐ＜０－０５，随药物浓度增加而无明显增大，Ｐ＞ ０－０５；ＣＩ于静息状态及低药物浓度时与对照组无差异，Ｐ＞０－０５，但随药物浓度增加而出现明显差异，Ｐ＜ ０－０５。术后ＬＶＰＷＴ、ＭＶＣＦＣ、ＳＩ、ＣＩ均随药物浓度增加而增大，与对照组比较无明显差异，Ｐ＞０－０５ 。结论 ＣＡＶＢ 患儿，静息状态下左室收缩功能正常，但药物负荷状态下出现储备功能不足，置入频率适应性起搏器后左室收缩储备功能可达正常。

Objective To investigate the changes of left ventricular systolic function pre-and post-implantation of ventricular rate adaptive pacemaker in children with complete atrioventricular block.Methods In 6 children aged 3～12 years with complete atrioventricular block and 8 normal controls were performed on fractional shortening (FS), ejection fraction (EF), left ventricular posterior wall thickening (LVPWT), velocity of circumferential fibre shortening (MVCFC), stroke index (SI), contractility index (CI) by dobutamine stress echocadiographic method.Results Before implantation, FS and EF increased with drug stress testing and did not significant distinguish from controls ( P>0.05 ).LVPWT, MVCFC and SI showed higher values compared with control subjects at rest and lower drug doses ( P<0 05 ), but no significant increased at larger drug doses ( P>0 05 ). CI showed not distinguish at rest and lower drug doses ( P >0 05), but showed significant distinguish with increased drug doses ( P>0.05 ) from controls. After implantation, LVPWT, MVCFC, SI and CI increased with drug stress testing and did not distinguish from controls ( P>0.05 ). Conclusions In complete atrioventricular block children, the left ventricular systolic function was normal at rest, with drug stress testing it showed poor cardiac reserve. After implantation of ventricular rate adaptive pacemaker, it had a normal cardiac reserve.