Implication of QRS Prolongation and Its Relation to Mechanical Dyssynchrony in Idiopathic Dilated Cardiomyopathy in Childhood

Chun An Chen, Cheng Hui Hsiao, Jou Kou Wang, Ming Tai Lin, En Ting Wu, Shuenn Nan Chiu, Hsin Hui Chiu, Mei Hwan Wu

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17 Citations (Scopus)


We explored the role of QRS prolongation (≥120 ms) and its relation to mechanical dyssynchrony and outcomes in childhood idiopathic dilated cardiomyopathy (IDC). A total of 89 patients ≤18 years old diagnosed as having IDC (21 days to 26 years of follow-up) were investigated. In 20 survivors with residual left ventricular (LV) dysfunction, mechanical (interventricular and intra-LV) dyssynchrony was assessed. The SD of time from the beginning of QRS prolongation to peak systolic contraction was measured in 12 LV segments by tissue Doppler imaging. A cut-off value >32.6 ms was used to define intra-LV dyssynchrony. The 1- and 5-year survivals were 70% and 53%, respectively. Requirement of intravenous inotropes at follow-up (hazard ratio 3.10) and initial LV ejection fraction (hazard ratio 0.95) were major prognostic factors. QRS prolongation, primarily left bundle branch block, was identified in 16 patients (18%) and tended to increase the risk of requiring inotropes. Moreover, none of those with QRS prolongation regained normal cardiac function at follow-up. Two patients with QRS prolongation showed marked improvement in cardiac function after cardiac resynchronization therapy. Mechanical dyssynchrony was noted in all patients with QRS prolongation and in 8% (interventricular) or 38% (intra-LV) of those without. In conclusion, QRS prolongation was common in childhood IDC and was possibly associated with persistent LV dysfunction and worse cardiac outcome. Mechanical (inter- and intraventricular) dyssynchrony was highly prevalent in those with QRS prolongation and was still often observed in those without.

Original languageEnglish
Pages (from-to)103-109
Number of pages7
JournalAmerican Journal of Cardiology
Issue number1
Publication statusPublished - Jan 1 2009
Externally publishedYes

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine


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