单腔起搏器心尖部起搏比例对心功能的影响

Effects of right ventricular apical pacing on heart function in patients with single-chamber pace- maker implantation

目的观察累计心室起搏百分比（CUM％VP，即起搏心率占总心率的百分比）对右室心尖部起搏患者心功能的影响。方法采用队列研究设计，将86例NYHA心功能I～Ⅱ级且符合纳入和排除标准的右室心尖单腔起搏患者分成两组进行随访观察。A组32例为CUM％VP／〉90％的患者，B组54例为CUM％VP〈90％的患者。以死亡、新发心力衰竭为终点，比较两组累积无终点事件生存率；同时观察左室射血分数（LVEF）、左室舒张末期内径（LVEDD）、QRS时间（QRSd）和从基线至随访结束时的改变（ALVEF、ALVEDD、AQRSd）。结果所有患者平均随访（34．8±11．7）个月，无失访和退出病例。随访结束时A组ALVEF、△LVEDD、aQRSd分别为（-5．4±7．3）％、（4．7±3．1）mm、（26．6±11．9）ms，B组分别为（2．5±5．9）％、（2．8±4．2）mm、（14．4±9．6）ms，两组比较差异均有统计学意义（P均〈0．05）。结论频繁右室心尖部起搏使左室射血分数降低，左室舒张末期内径以及QRS时间增加，增加单腔心室起搏器置入患者心力衰竭发生危险，定期程控尽量减少心室起搏可以延缓心力衰竭的发生。

Objective To observe the effect of the cumulative percentage of ventricular pacing （CUM% VP） on heart function of patients with right ventricular apical pacing. Methods A cohort study was conducted among 86 patients with sick sinus syndrome （SSS） or atrioventrieular block （AVB） after single-chamber ventricular pacemaker implantation. According to the cut-point 90% of CUM% VP, the patients were divided into group A（ CUM% VP≥90% , n = 32） and group B（ CUM% VP 〈 90% , n = 54）. The primary composite endpoint was defined as new-onset heart failure （ NYHA class ≥Ⅲ or hospi- talization for heart failure） and death from all causes. The left ventricular ejection fraction （LVEF）, left ventrieular end-diastolic diameter（LVEDD） and the QRS duration were measured. Their absolute altera- tions（ A LVEF, A LVEDD, A QRSd） as compared with the baseline measurements were also calculated. Results Before pacemaker implantation, there were no differences in age, sex, basic diseases, cardiac function, and constituent ratio in type of pacemakers between group A and B. There were no death, dropout, and loss to follow-up. By comparing the outcomes of group A with those of group B at the end of the study, it showed that： the absolute decrease in LVEF（ALVEF） in group A was significantly larger [ A LVEF ： （ -5.4 ± 7.3 ） % vs （ 2. 5 ± 5.9 ） % , P 〈 0. 05] than those of group B ; the absolute increase in LVEDD （ A LVEDD） in group A was significantly larger [ A LVEDD ： （4.7 ±3. 1 ） mm vs （ 2. 8± 4.2 ） mm, P 〈 0. 05 ] than those of group B ; the absolute increase in QRSd （ A QRSd） was significantly larger [AQRSd：（26.6±ll.9）msvs （14.4±9.6）ms, P 〈 0. 05 ] than those of group B. Conclusions Fre- quent right ventricular apical pacing increases the risk of new-onset of heart failure in patients with single-chamber pacemaker implantation, and regularly program the pacemaker to de-crease the fight ventricular apical pacing as far as possible can delay the occurrence of heart failure.