Abstract 2974: Midterm Results Of Resynchronization Therapy In Pediatrics: Do We Need New Guidelines?

Cardiac resynchronization therapy (CRT) is an accepted therapy for adults with dilated cardiomyopathy (DCM) and has been shown to improve ejection fraction and functional capacity. CRT has been used in children for over 4 years with a variety of indications which differ substantially from those commonly used for adult patients. We reviewed the results of CRT in the combined Stanford-UCSF pediatric electrophysiology program over the past 4 years, in order to evaluate efficacy of CRT in different clinical scenarios. We have provided CRT to 31 patients (15 female) between 2003 and 2007. The mean age at implantation was 7.3 ± 6.6 years. 21 patients had congenital heart disease (CHD) of whom 4 had single ventricle physiology. 5 patients had DCM and 5 had congenital complete heart block with reduced LV systolic function (CCHB). All patients with DCM met criteria for CRT in adults (QRS duration < 120 msec and EF > 35%). Implantation in the other patient groups was performed at the discretion of the physician. Mean follow-up was 26 ± 15 months. Ejection Fraction (EF), by echo, was 30 ± 11% at baseline which improved to 41 ± 19% at last follow-up (p < 0.05). EF as well as LV end diastolic volume and LV end systolic volume showed immediate improvement followed by additional continued improvement over the study period. CHD and CCHB patients reported improved symptoms and had improved cardiac indices by echo. DCM patients, however, showed no improvement and instead had a gradual decrease in ejection fraction over the study period (30 ± 11% to 18 ± 11%, p< 0.01). Two of the 5 DCM patients were transplanted, and one died of pump failure. Conclusions: CRT is efficacious in selected patients with congenital heart disease, or those with congenital complete heart block. The role of CRT in pediatric patients with dilated cardiomyopathy is less clear, but adult selection criteria may not be applicable to children. Comparison of EF preCRT and at last follow-up