Implantable cardioverter-defibrillators (ICDs) have been shown to successfully treat life-threatening arrhythmias in high-risk adults with hypertrophic cardiomyopathy (HCM).¹ Children represent <1% of individuals with ICDs, and paediatric studies include few children with HCM. This study reports the experience with ICDs in children with HCM in a single referral centre.

METHODS

Between 1993 and February 2006, 160 consecutively referred patients with HCM (age ⩽16 years) underwent clinical evaluation using 12-lead ECG, two-dimensional, M-mode and Doppler echocardiography, Holter monitoring and cardiopulmonary exercise testing using previously described methods.² Risk markers for sudden cardiac death (SCD) were: (1) family history of SCD; (2) unexplained syncope; (3) abnormal blood pressure response during upright exercise; (4) non-sustained ventricular tachycardia; and (5) severe left ventricular hypertrophy (⩾30 mm).² Patients with previous cardiac arrest or with ⩾2 risk factors were considered for ICD implantation.² All patients who underwent ICD implantation during this period were included in this study.

Informed consent for ICD implantation was obtained from a parent in all cases. Devices were implanted under general anaesthesia into subpectoral pockets, using transvenous lead systems. Sixteen patients received dual chamber devices and six received single-chamber devices. Stored ICD data were obtained every 6 months or within 24 h of treatment. Discharges were judged appropriate when triggered by ventricular tachycardia or ventricular fibrillation, or inappropriate if triggered by …