右室间隔部不同部位起搏对心功能和心室收缩同步性的影响

Effects of pacing sites in the right ventricular septum on cardiac function and ventricular systolic synchrony

目的探讨右心室间隔部位的最佳起搏位置。方法61例高度或完全性房室传导阻滞且植入永久起搏器的患者，按X线影像结果及心室电极头端所在位置，将患者分为右室低位间隔组（22例）、右室中位间隔组（21例）及右室高位间隔组（18例）。随访术后1年的心室起搏比例、心电图及心脏彩超等资料，比较患者QRS波时限、R波切迹和左室射血分数（LVEF）、左室舒张末期内径（LVEDD）、左室短轴缩短率（FS）、室间隔与左心室后壁间的收缩延迟时间（SPWMD）及主动脉射血前时间与肺动脉射血前时间之差（IVMD）等，并分析右心室间隔部位的最佳起搏位置。结果3组患者术前基线资料如年龄、性别、基础疾病、EF、LVEDD及FS之间差异无统计学意义。术后起搏模式均为DDD，3组患者心室起搏比例差异无统计学意义。术后1年：与低位间隔组相比，中位间隔组其心室起搏QRS时限短、R波切迹少、FS值高、SPWMD时限短、IVMD时限短，2组之间EF值及LVEDD无明显差异；与高位间隔组相比，中位间隔组心室起搏QRS时限短、切迹少、EF值高、SPWMD时限短、IVMD时限短，FS值及LVEDD无统计学差异；与高位间隔组相比，低位间隔组QRS波时限短、LVEF值高，LVEDD、FS、SPWMD及IVMD之间无差异。结论相对于右室间隔面其他部位起搏，右室中部间隔面起搏时QRS波时限更短，对心脏功能及心脏收缩同步性等影响最小，有更好的血流动力学效果。

Objective To determined the optimal pacing site in the right ventricle. Methods A total of 61 patients were enrolled into the current study who were implanted a pacemaker due to advanced or complete atrioventricular block. According to the location of the electrode tips by X - ray, the patients were divided into a low - septal implantation group （22 cases）, a mid - septal implantation group （21 cases） and a high - septal implantation group （ 18 cases）. They were subjected to followed - up visits one year after surgery, when data were collected including cumulative ventricular pacing proportion （ Cum VP% ） , electrocardiogram and Color Doppler sonographic in assessment of the heart. Their QRS complex, Croehetage （notch） on R wave, left ventricular ejection fraction （LVEF）, left ventrieular end diastolic diameter （LVEDD） , left ventricular fractional shortening （FS） , septal - to - posterior wall motion delay （SPWMD） and interventricular mechanical delay （IVMD） were compared to determine the optimal pacing site in the right ventricular septum. Results There were no statistic differences among the three groups as to baseline information like age, gender, primary disease, EF, LVEDD and FS before operation. After surgery, the pacing modes were all DDD, while no significant differences were seen in the Cum% VP among the three groups. For the follow - up visit one year later, compared with the low - septal implantation group, the mid - septal group produced narrower QRS complex, shorter SPWMD and IVMD, as well as less frequency in notch on R wave and higher values of FS. There was no statistic difference in EF and LVEDD between the two groups. Compared with the high - septal implantation group, the mid - septal group produced narrower QRS complex, shorter SPWMD and IVMD, as well as less frequency in notch on R wave and higher values of EF. There was no statistic difference in FS and LVEDD between the two groups. Compared with the high - septal implantation group, the low - septal group produced narrower QRS complex and higher values of LVEF. There was no statistic difference in LVEDD, FS, SPWMD and IVMD between the two groups. Conclusion Pacing from the middle site of the right ventricle results in narrower QRS complex with the least effects on cardiac function and ventricular systolic synchrony and better hemodynamic results, in comparison with other pacing sites.