Abstract 14900: Impact of ICD Programming Changes to Avoid Inappropriate Shocks in the Young

Abstract

Introduction: ICD therapy in young pts has been shown to improve mortality but inappropriate ICD shocks (IAS) occur in up to 25% of young pts. Adult studies have shown that changing the VF detection rate (RATE) and/or duration to detection (DUR) results in fewer IAS without increasing mortality. The purpose of this study is to assess the impact of RATE and/or DUR changes to avoid IAS in young pts with ICDs. Methods: This two-part study initially consisted of a retrospective analysis of IAS in young pts with ICDs at our institution from 2007-2012. A total of 1200 intervals from EGMs recorded from 16 pts with IAS were analyzed and the risk for VF detection was calculated at various RATE and DUR. Analysis of true episodes of VT/VF in 8 pts was also performed. We found that changing the RATE from 200 bpm to 250 bpm resulted in a 49-85% reduction of risk for IAS. Based on this analysis, the RATE was increased to 220-250 bpm in our ICD pts from 2012-2015. The clinical rate of IAS was then compared before and after changing ICD programming to higher RATE. Results: 64 pts (ages 8y to 57y, mean 21y, 41 male) were included in this study. In the time period from 2007-2012, IAS occurred in 30% of pts (50% due to lead malfunction and 50% due to SVT). ICD programming was changed to VF RATE of 220-250 bpm with DUR of 18/24 in all ICD pts in 2012 and thereafter. There was a significant reduction of IAS with ICD program changes (30% vs 1.5%, p=0.001) with no change in appropriate shock rate (APS) or lead malfunction rate between the two time periods (see table). There were no episodes of syncope or death in those with APS before or after programming changes. Conclusions: The incidence of IAS in young pts can be reduced by changes in ICD programming. Increasing the RATE has a greater impact on reduction of risk for IAS compared to prolonging DUR and did not result in an increase in syncope or death. These findings may help to standardize programming of ICDs in young pts.