| ǥ : Clinical award session
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ȣ - 540500 2 |
| Right Ventricular Epicardial Pacing and Left Ventricular Dysfunction in Children with Isolated Congenital Complete Atrioventricular Block
–Predictive and Preventive Factor |
| 서울대학교 어린이병원 소아심장과¹, 흉부외과² |
| 김나연¹, 배은정¹, 권보상¹, 김기범¹, 노정일¹, 김웅한², 이정렬², 김용진² |
Background and Objectives Permanent pacemaker implantation is often inevitable for the children with congenital complete atrioventricular block (CCAVB). We aimed to determine the effect of right ventricular (RV) epicardial pacing on the left ventricular (LV) function and identify the potential risk factors for the LV dysfunction. Methods We performed a retrospective study on all pediatric patients with isolated CCAVB who had received the pacemaker implantation for > 6 months from April 1987 to January 2010. Echocardiographic parameters of LV dimension (LVD) and function before and after the epicardial pacemaker implantation were reviewed, and their correlation with ECG, cardiothoracic ratio on chest x-ray, location of pacemaker lead, mode of pacemaker were evaluated for the patients. Patients with complex congenital heart disease or postoperative heart block were excluded. Result Twenty-six patients were enrolled in the study. The median age at pacemaker implantation was 2.5 years with an average follow-up of 11.1 years Eleven patients showed LV dilation. Six patients were noted to develop LV dilatation with dysfunction. By univariate analysis, longer duration of pacemaker implantation and pre-pacemaker LV dilatation were correlated with LV dilatation after the RV pacing (p<0.05). Patients with ventricular lead located in RV anterior free wall showed lower LVEF and larger systolic LVD, compared with the patients with ventricular lead in RV apex (LVEF 40.6±17.3 vs. 63.2±7.2 and LVDs Z score 5.54±4.18 vs. 1.13±1.21 respectively, P<.001). Neither pacemaker mode nor paced QRS duration showed significant correlation with LVEF and LVD. Among the 6 patients with LV dysfunction, 4 patients achieved LV functional improvement; LVEF was improved from 26.5±6.9 to 56.5±2.3 after the biventricular pacing (n=2) or the re-location of pacing site from RV anterior wall to RV apex (n=2). Conclusion Epicardial RV anterior free wall pacing in CCAVB was associated with late LV dysfunction, which could be reversible after biventricular pacing or RV apical pacing. Late LV dysfunction after pacemaker implantation could be prevented by an effort on careful ventricular lead positioning making less dyssynchrony. Close follow up on late LV dilatation and dysfunction is needed in all RV paced patients.
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