Eligibility for subcutaneous implantable cardioverter-defibrillators in the adult congenital heart disease population.

BACKGROUND: Patients with adult congenital heart disease (ACHD) have an increased risk of arrhythmic, sudden cardiac death. The subcutaneous implantable cardioverter defibrillator (S-ICD) provides a potentially safer alternative to transvenous ICDs in ACHD. Suitability for S-ICD depends on the surface ECG which is often abnormal in ACHD patients. This study investigates the proportion of ACHD patients who meet the screening criteria for S-ICD METHODS: A standard screening ECG was performed in 102 patients with complex ACHD (Tetralogy of Fallot, Fontan Circulation, Transposition of the Great Arteries). This process was repeated post-exercise for patients who also had an exercise test.

RESULTS: Three quarters (75.4%) of ACHD patients meet screening criteria for an S-ICD with at least 1 suitable vector. The most common number of acceptable vectors in the eligible group was 2 (35% of total population). In only 12% were all three vectors suitable whilst 28% had only 1. The primary vector (equivalent of ECG lead III) was the most common suitable vector, found in 62% of participants who had appropriate sensing vectors. 25 (24.5%) patients failed to meet the S-ICD screening criteria. Of these, 14 had repaired tetralogy of Fallot. 92% of patients with a Fontan circulation met ECG screening criteria. Of those who had the protocol repeated following their cardiopulmonary exercise test (n = 14), only 1 additional patient failed eligibility criteria.

CONCLUSIONS: A quarter of ACHD patients do not meet eligibility criteria for the S-ICD. However, more than 90% of patients with a Fontan circulation are suitable for an S-ICD. This article is protected by copyright. All rights reserved.