Abstract 14328: Comparison of Right and Left Pectoral ICDs with Single and Dual Coil Leads; A Computational Simulation
Background: Clinical studies show no difference in single and dual coil defibrillation thresholds for left pectoral (L) ICDs, however, data on right pectoral (R) ICDs is limited. We used full torso finite element models (FEMs) to simulate and compare R and L ICD implants.
Methods: Full torso MRI (9 y/o with congenital heart disease) and CT scan (27 y/o with normal cardiac anatomy) were obtained prior to ICD implantation and formulated into FEMs of defibrillation that have been validated previously through measurements. Electrostatic defibrillation simulations were performed using single and dual coil shocks. The RV shocking coil was positioned in 13 locations from base to apex including the RVOT with the second coil positioned in the SVC. The ICD generator was placed in R and L pectoral positions. Defibrillation thresholds (DFT) were calculated for 156 cases.
Results: For R ICDs, DFTs for single coil were larger than with dual coil in both torsos (average increase in DFT 26.5 ± 14.8 J, p<0.001 and 16.1 ± 9 J, p<0.001) but only mildly increased (average increase in DFT 4.4 ± 0.8 J, p<0.001 and 3.1 ± 0.8 J, p<0.001) with L ICDs. Chart 1 shows that RV apex DFTs were the lowest in all cases. RVOT DFTs strongly exceeded those from mid RV for R ICDs but were only mildly increased for L ICDs. Coil to coil, inactive generator DFTs were similar to dual coil DFTs with R ICDs but largely increased for L ICDs.
Conclusions: Full torso FEMs confirm that dual coil leads are not necessary for L ICDs but predict that dual coil leads provide a significantly better margin of safety for R ICDs. If frequent RV pacing is anticipated, RVOT coil positions are adequate for L ICDs but not R ICDs. RV apical coil positions are superior for single coil leads especially for R ICDs. Coil to coil shocks are efficacious in R ICDs but not for L ICDs.
- © 2011 by American Heart Association, Inc.