Sustained ventricular tachycardia (VT) and cardiac arrest are a major cause of mortality in adult congenital heart disease patients. Implantable cardioverter defibrillators (ICD) can protect against this. ESC guidelines state that ICDs should be considered following spontaneous sustained VT and in all survivors of cardiac arrest; and in patients at high risk of this.Methods
All ICD recipients in the GUCH database were included (n = 40). Medical records were retrospectively analysed. Data were collected on initial diagnosis, reason for ICD implantation, date of implantation, complications, and ICD discharges between the time of implant and data collection.Results
Demographics: 55% of patients were male; age range 20–71 years, mean age 45 years, median age 43 years. Mean age at implantation of ICD was 41 years. Mean follow up was 4.2 years (median 2.5 years).Results
Diagnosis: 47.5% of patients had repaired Tetralogy of Fallot (TOF). 15% of patients had transposition of the great arteries.Results
Reason for ICD: Fifteen patients (37.5%) received ICD after symptomatic sustained VT. One patient underwent catheter ablation of VT before ICD was implanted. Eleven patients (27.5%) received ICD after cardiac arrest. Fourteen (35%) had an ICD implanted as primary prophylaxis.Results
Since implantation, five patients received an appropriate full-output shock for VT from ICD. 11 (27.5%) patients suffered significant complications (inappropriate shocks secondary to atrial arrhythmias 7, infection requiring extraction 3 and lead fracture 1). Of inappropriate shocks, 6 were due to atrial flutter or fibrillation and 1 due to oversensing. Tetralogy of Fallot patients had comparatively much higher complication rate than patients of other diagnoses (42% vs 14%). Similar proportions of primary and secondary prevention patients received appropriate shocks from the device (14% vs 11.5%).Conclusions
Most patients had ICD for secondary prevention (a total of 65%) due to sustained VT or cardiac arrest, the majority being in patients with repaired Fallot’s tetralogy. There was a 3.0% annual appropriate shock rate. However, there was a high incidence of complications with nearly a third suffering a major complication (6.5% per annum); a risk that was increased for Tetralogy of Fallot patients. The rate of adverse effects from ICD identified here is similar to that previously reported for hypertrophic cardiomyopathy patients. The risks and benefits of ICD implantation must be clearly discussed with patients prior to implantation. There was a near-equal incidence of appropriate therapy in both primary and secondary prevention groups. Further research is warranted into the use of primary prevention ICDs in adult congenital heart disease.