Introduction
As awareness of sudden death syndromes grows, increasing numbers of children are being referred for ICD which can be challenging in infants and small children. We review our experience with focus on those <5 year old.
Methods and Results
Retrospective chart review. Since 1996, 24 children received an ICD. Indications included: 12/24(50%) long QT syndrome, 4/24(16%) hypertrophic cardiomyopathy, 4/24(16%) VT/VF (1 idiopathic, 3 related to structural heart disease); 3/24(12%) catacholaminergic polymorphic VT, 1/24 Brugada syndrome.
The majority were for primary prevention. None have required shocks since insertion. 8/24(33%) patients were for secondary prevention, many have required device discharge.
36 procedures were performed on 24 patients. Breakdown of lead integrity accounted for the majority of lead revisions/replacement. Abrasion and damage from external forces were the major causes.
Age at first ICD ranged between 6d and 15y. 5/24(21%) were<5y. The youngest child had an ICD-implanted was for LQTS diagnosed on the day of birth after ventricular fibrillation arrest.
In the patients under five years of age, 4/5 patients had the shocking coil tunnelled subcuaneously from the device heading laterally, then superiorly toward the left axilla. The defibrillation threshold in these patients was between 3J and 35J. A pericardial-defibrillator-patch was used in one patient.
Conclusion
ICD-implantation has been safe but there is a significant rate of late lead revision. Subcutaneous placement of shocking coils in the very young is an effective temporising measure. Better definition of the genetic and molecular basis underlying many conditions allows better discrimination of who will benefit.