Aims: To determine the efficacy of the implantable loop recorder (ILR) in patients with congenital heart disease.
Methods and results: Retrospective data analyses of all patients with congenital heart disease undergoing ILR implantation in a congenital cardiac centre. Of 78 ILRs implanted between July 2000 and October 2007, 22 (15 male) patients had congenital heart disease. The median age at implantation was 15.5 years (7.0-46.5). Six patients had neurodevelopmental delay. Indications for implantation were syncope (n = 15), palpitations (n = 4), and pre-syncope (n = 3). Median implantation time was 19 months (1-30). Explantation data were available in 16 patients (73%). Implantable loop recorders were explanted following establishment of positive diagnosis (n = 3), negative diagnosis (n = 7), and at the end of battery life (n = 4). One patient died with the ILR in situ. One device eroded after 2 months without further complication. Following ILR interrogation, diagnosed arrhythmias included ventricular tachycardia (n = 2) and sinus node dysfunction (n = 1). On the basis of these findings, two patients had intracardiac defibrillators and one patient had a dual-chamber pacemaker implanted.
Conclusion: Implantable loop recorders lead to a positive or negative arrhythmic diagnosis following explantation in 71% of patients with congenital heart disease. This is particularly beneficial in patients with neurodevelopmental delay where accurate history is often limited.