右心室流出道与右心室心尖部起搏对心室收缩同步性和心功能的影响

目的研究右心室流出道(right ventricular outflow tract,RVOT)间隔部和右心室心尖部(right ventricularapex,RVA)起搏对心脏收缩同步性、收缩功能的影响,探讨RVOT间隔部起搏的意义。方法 50例病态窦房结综合征患者分为RVOT组(n=25)和RVA组(n=25),起搏器置入1个月后通过调整房室间期使心室节律全部为起搏节律或房室结自身下传节律,观察起搏参数,并行超声心动图检查。结果RVOT组与RVA组电极导线植入时间、X线曝光时间比较,差异无统计学意义(P>0.05)。全部患者未出现植入并发症。两组随访1个月时起搏参数比较,差异无统计学意义(P>0.05)。RVOT组和RVA组起搏后的QRS波时限较前明显增宽,差异有统计学意义RVOT组:(135±8)ms vs.(88±8)ms,P<0.001;RVA组:(154±8)ms vs.(90±6)ms,P<0.001]。RVA组起搏后QRS波时限较RVOT组增宽更为明显,差异有统计学意义(P<0.001)。两组起搏后室间机械延迟(interventricularmechanical delay,IVMD)和室间隔-左心室后壁收缩运动延迟时间(septal-to-posteriowall motion delay,SPWMD)较起搏前均显著增加,差异有统计学意义(P<0.001)。RVA组起搏后IVMD和SPWMD绝对值较RVOT组显著延长,差异有统计学意义IVMD:(38±7)ms vs.(24±5)ms,P<0.001;SPWMD:(118±21)ms vs.(60±11)ms,P<0.001]。两组左心室舒张末内径及左心室射血分数比较,差异无统计学意义(P>0.05)。结论右心室起搏会造成心室收缩不同步,RVOT起搏对心室收缩不同步的影响较RVA起搏小,提示RVOT起搏是较为生理的起搏位点。

Effects of right ventricular outflow tract and right ventricular apex pacing on ventricular contraction synchrony and cardiac function

Objectives To compare the effects of right veutricular outflow＇ tract （RVOT） septum pacing and right ventrlcular apex （RVA） pacing on ventricular contraction synchrony and cardiac function. Methods A total of 50 patients with sick sinus syndrome were randmnized into two different cardiac pacing sites of RVOT （RVOT group, n= 25） and RVA （RVA group, n=25）. Ventricular contraction synehrony and cardiac function were studied under pacing rhythm of ventricular pacing and independent rhythm by adjusting to the auriculoventrieular （AV） interval 1 month after pacemaker implantation. Results Duration of electrode implantation and duration of X-ray exposure in RVOT group and RVA group had no significant difference （P〉0.05）. All the patients did not suffer from implantation complications and there was no significant difference in pacing parameters during follow up between the two groups （P〉0.05）. QRS durations after pacing in RVOT group and RVA group significantly increased RVOT group： （135±8） ms vs. （88±8） ms, P〈0.001 ; RVA group： （154±8） ms vs. （90＋6） ms, P〈0.0011, and QRS durations in RVA group widened much more than those in RVOT group （P〈0.001）. In the two groups, interventrieular mechanical delay （IVMD） and septal to posterior wall motion delay （SPWMD） significantly increased after pacing （P〈0.001） ; IVMD and SPWMD in RVA group widened much more than those in RVOT group IVMD： （38±7） ms vs. （24±5） ms, P〈0.001 ; SPWMD： （ 118±21 ） ms （60±11） ms, P〈0.001]. Left ventricular end-diastolic dimension and left ventricular ejection fraction of the two groups were manifested no significant changes （P〉0.05）. Conclusions Right ventricular pacing results in ventricular desynchronization. RVOT pacing is a better pacing site with less influence on ventrlcular contraction synchrony.