Bashir, Mohammad U

Introduction: The subcutaneous implantable cardioverter defibrillator (S-ICD) is an attractive option for patients with congenital heart disease (CHD) in whom a transvenous system is contraindicated. However, more than 10% of adult patients with CHD fail S-ICD screening due to a large T- to R-wave ratio. We hypothesized right-sternal electrodes may permit S-ICD placement in patients who fail left-sternal screen. Methods: We prospectively screened 40 patients with CHD for S-ICD using the standard proprietary approach. We also screened with right sternal electrodes (with left can electrode position). Results: The mean age of the cohort was 46+/-15 years; 24 males were enrolled. CHD anomalies consisted of tetralogy of Fallot (n=11), Ebstein’s anomaly (n=7), atrial septal defect (n=6), dextro-looped transposition of the great artery (n=5) and other (n=11). Left side screening ECG failed in 9 patients (23%), five of whom passed with right sternal electrodes, increasing the pass rate from 77% to 90%. Figure shows the screening ECG and chest x-ray of a patient who failed in all three vectors on the left side but passed in the alternative vector on the right side and underwent right sided implantation. Conclusions: The addition of right sternal electrodes during screening increases S-ICD eligibility and may avoid thoracotomy for high risk patients with CHD.