Cardiac resynchronization therapy (and multisite pacing) in pediatrics and congenital heart disease: five years experience in a single institution.

INTRODUCTION: Clinical evidence supports the use of cardiac resynchronization therapy (CRT) in adults with heart failure, but experience in pediatrics and congenital heart disease (CHD) is limited in terms of patient numbers and follow-up. We sought to determine the functional assessment and clinical outcomes in pediatric and CHD CRT patients followed uniformly at one institution.

METHODS: Retrospective review of 60 consecutive patients who underwent CRT between 2002 and 2007.

RESULTS: At implantation, median age was 15.0 years (5 months to 47 years). Overall, 46 patients had CHD (77%) and 14 had dilated cardiomyopathy. Prior to CRT, 92% were on heart failure treatment drugs and 55% had pacemakers. Median follow-up time was 0.7 years (1 day-5.3 years). Median QRS width decreased from 149 to 120 ms (P < 0.001). Median ejection fraction (EF) increased from 36% to 42% (P < 0.001) and improvement was particularly evident in the group with CHD. Of note, 8 of 13 patients with single ventricle morphology had a "strong CRT response," defined as either an improvement of 2-3 ordinal points in NYHA classification and/or increased ventricular function by >or= 10 EF units. Overall, an improvement in functional status was observed in 39 of 45 patients (87%) with sufficient follow-up data.

CONCLUSIONS: Children and CHD patients treated with CRT have acute improvement in ventricular function, but implantation may require individualized planning and unconventional approaches. Future important goals include preimplant determination of CRT responders in pediatric and CHD patients, optimizing lead placement and programing, as well as long-term CRT device management issues.