Dilated cardiomyopathy after long-term right ventricular apical pacing in children with complete atrioventricular block: role of setting of ventricular pacing.
BACKGROUND
Pediatric patients paced for complete atrioventricular block (CAVB) are at risk of developing dilated cardiomyopathy (DCM). We sought to explore the role played by the setting of ventricular pacing.


RESULTS
A total of 35 patients <18 years of age at diagnosis were enrolled. Twenty-eight (80%) received pacemakers after a mean follow-up of 10 years, and most were paced from right ventricular (RV) apex (n = 23). None of the 7 patients without pacemakers developed DCM, whereas 8 (35%) paced from RV apex had DCM 2.6 +/- 2.2 years after pacing. The percentage of ventricular pacing was >90% in all patients. Multivariate analysis revealed that the cumulative Z score of lower ventricular rate setting was the single most important risk factor for DCM (HR, 3.14; 95% CI, 1.07-9.19; P = .037). Subgroup analysis in patients with VVI/VVIR modes revealed an even stronger predictive value of the cumulative Z score of lower ventricular rate setting (HR, 9.12; 95% CI, 1.53-54.24; P = .015).


CONCLUSIONS
Higher setting of the lower ventricular rate, though still within the age-appropriate range, was associated with increased risk of developing DCM in pediatric patients with CAVB and chronic RV apical pacing.
Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan.
Chun-An
CA
Chen
Jou-Kou
JK
Wang
Ming-Tai
MT
Lin
Chun-Wei
CW
Lu
Kun-Lang
KL
Wu
Shuenn-Nan
SN
Chiu
Hsin-Hui
HH
Chiu
En-Ting
ET
Wu
Hung-Chi
HC
Lue
Mei-Hwan
MH
Wu
D000293:Adolescent; D054537:Atrioventricular Block / Q000503:physiopathology* / Q000628:therapy*; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects* / Q000379:methods; D002311:Cardiomyopathy, Dilated / Q000209:etiology* / Q000503:physiopathology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D012189:Retrospective Studies; D013997:Time Factors; D016278:Ventricular Function, Right / Q000502:physiology*