CARDIAC RESYNCHRONIZATION THERAPY IN CONGENITAL AND PEDIATRIC HEART DISEASE: A RETROSPECTIVE EUROPEAN MULTICENTER STUDY

Objectives: Data on cardiac resynchronization therapy (CRT) in congenital and pediatric heart disease are scarce. This study collected a multicenter European experience by addressing the members of the Association for European Pediatric Cardiology.
Methods: CRT was applied in 74 pts aged 0.24 - 67.5 (median 16.9) yrs with congenital heart disease (N=50), cardiomyopathy (N=7), congenital complete AV block (N=6) and other disease (N=2) with systemic left (N=49), right (N=22) or single (N=3) ventricular dysfunction and spontaneous (N=16) or pacing induced (N=58) systemic ventricular desynchronization using transvenous (N=28), thoracotomy (N=21) or mixed (N=25) lead systems. Concurrent cardiac surgery was performed in 11 (14.9%) pts. Follow-up ranged from 0.0-45.8 (median 8.1) months.
Results: QRS duration decreased from median 160 to 132 ms (p<0.001), Z-score of the systemic ventricular enddiastolic dimension (indexed to a normal left ventricle) from +3.28 to +1.65 (p<0.001) and grade of systemic AV valve regurgitation from 1.0 to 0.0 (p<0.001). Ejection fraction or fractional area of change increased from mean 30±14 to 41±13 % (p<0.001). Reverse remodeling was better for systemic LV than RV (decrease in the Z-score of the enddiastolic dimension by 2.1 vs 0.67, p<0.05). NYHA class decreased from median 2.0 to 1.5 (p<0.001). A total of 9 pts (12.2%) did not respond to CRT, 3 pts died (ventricular arrhythmia=2, circulatory arrest=1) and 3 of 8 pts could be delisted as HTx candidates.
Conclusions: In congenital and pediatric heart disease CRT was more frequently indicated for conventional pacing induced than spontaneous ventricular desynchronization. Major beneficial mid-term effects in terms of reverse systemic ventricular remodeling and functional improvement were observed. (RG supported by the Research Project of University Hospital Motol No 00064203/6301)