Use of an implantable loop recorder in the evaluation of children with congenital heart disease

Background A recently developed implantable loop recorder (ILR) has been used in adult patients whose syncope remains unexplained in spite of extensive investigations. Syncope in the patient with congenital heart disease presents a diagnostic challenge. We applied this technology to a cohort of pediatric patients. Methods We reviewed our experience with an ILR in patients with congenital heart disease with syncope or palpitations after conventional investigations failed to identify a cause for the symptoms. Results ILRs were implanted in 4 patients with congenital heart disease at 2 centers for investigation of syncope (n = 2), near-syncope (n = 1), and palpitations (n = 1). Implantations were performed at a mean age of 5.9 ± 0.9 years (4.2 to 7.6 years) and a mean weight of 26.7 ± 6.6 kg (15.7 to 42.5 kg) with patients under general anesthesia, with no complications. All patients experienced typical symptoms and activated the device appropriately at a median of 86 days (46 to 102) after implantation. Each patient had good-quality data that allowed interpretation of the rhythm. In 2 of 4 cases, a likely cause for the symptoms was identified, with exclusion of more malignant arrhythmic diagnoses in all patients. Escalation of therapy was avoidable in all patients on the basis of the data recorded by the ILR. Conclusions Recently developed loop recorder technology can be implanted in the young child without difficulty. The ILR proved to be very useful for excluding malignant arrhythmias as a cause of symptoms in these patients at high risk. (Am Heart J 2002;143:366-72)