ICD therapy for primary prevention of sudden cardiac death after Mustard repair for d-transposition of the great arteries

Years and decades after the Mustard atrial switch repair for d-Transposition of the great arteries, there is a subset of patients at increased risk for sudden cardiac death due to ventricular tachyarrhythmias. To date, little is known about indications, efficacy and benefit of internal cardioverter defibrillator (ICD) therapy indication in these patients. To characterize the Mustard patients already treated with an ICD, we conducted a single center case control study (n = 41). The charts of all patients after Mustard procedure at our institution were systematically reviewed for history, echocardiographic findings, arrhythmias, hemodynamics and medication as well as ICD discharges and complications. Significant differences between ICD (n = 12) and non-ICD patients (n = 29) were found regarding the stage of heart failure, need for heart failure medication, QRS duration and left ventricular diameter and performance. Inappropriate ICD discharges due to rapidly conducted atrial reentrant tachycardia and sensing failure were frequently observed. In 17 % of our Mustard patients with an ICD, infection of the implantation site required surgical revision. All ICD patients were of male gender. Patients after ICD implantation represent a subgroup among our Mustard patients with a more advanced state of cardiac disease. Not only systemic right ventricular diameter and performance but also subpulmonary left ventricular performance was an important factor predicting the long-term course of these patients. Prevention of inappropriate discharges requires decent device programming, close monitoring of lead integrity and treatment of atrial tachycardias.