Abstract 2971: Managed Ventricular Pacing In Pediatric Patients And Patients With Congenital Heart Disease
Introduction: Ventricular dyssynchrony induced by ventricular pacing (VP) may predispose patients (pts) to congestive heart failure. The detrimental effects of VP are directly related to the cumulative percentage of VP (Cum%VP). Managed ventricular pacing (MVP, Medtronic) is a novel pacing algorithm developed to minimize unnecessary VP by uncoupling atrial pacing from VP. The use, efficacy, and safety of MVP in pediatrics pts and pts with congenital heart disease (CHD) have not been described.
Methods: A multicenter review evaluated all pediatric pts < 22 years old and older pts with CHD that had an implanted device using an MVP algorithm. Primary outcome variables were Cum%VP and adverse events. A subgroup analysis evaluated pts that had a DDD/R pacemaker prior to MVP device with similar low pacing rate and compared Cum%VP before and after initiation of MVP, using Wilcoxon signed-rank test.
Results: 62 patients from 6 centers were included for the review (see table⇓). Mean age at MVP device implant was 21.5 ± 9.6 years (range 7–51). 63% of pts had CHD. With MVP device, mean Cum%VP was 4.3 ± 14.6% (range 0 – 83.7). By pacing indication, Cum%VP was 2.9 ± 6.5% in pts with sinus node dysfunction (n = 24), 34.8 ± 41.3% in pts with atrioventricular (AV) block (n = 5), and 0.6 ± 1.0% in pts with an ICD (n = 33). 11 patients were eligible for subgroup analysis. With DDD/R pacing, mean low rate was 64 ppm and mean paced/sensed AV intervals were 251 and 241 ms. With MVP, mean low rate was 63 ppm and mean paced/sensed AV intervals were 193 and 166 ms. Compared to DDD/R, Cum%VP significantly decreased with MVP (67.1 ± 29.4 vs. 9.2 ± 24.8%; p < 0.005). One MVP-related adverse event occurred: a pt with intermittent AV block had symptoms with nonconducted atrial beats and was reprogrammed to DDD.
Conclusions: MVP can be used safely and can significantly reduce unnecessary ventricular pacing in pediatric pts and pts with CHD. MVP should be considered when choosing a pacing mode for this pt population.