Our approach to implantable cardioverter-defibrillator (ICD) placement in children with hypertrophic cardiomyopathy

VT: ventricular tachycardia; ICD: implantable cardioverter-defibrillator; LVH: left ventricular hypertrophy; NSVT: nonsustained ventricular tachycardia; HCM: hypertrophic cardiomyopathy; SCD: sudden cardiac death; LGE: late gadolinium enhancement; CMR: cardiovascular magnetic resonance; LV: left ventricular.

* Massive LVH can be defined with an absolute threshold (≥30 mm) or z-score (eg, z-score >10). However, consensus is lacking regarding which z-score cut-off should be used to define massive LVH in the context of SCD risk assessment

¶ Risk of SCD is increased in patients with more frequent, longer, or faster runs of NSVT.

Δ The available studies have reached variable conclusions regarding the prognostic value of family history. Nevertheless, it is considered a major risk factor for the purpose of risk stratification.

◊ Decisions regarding ICD placement in these circumstances should be made in the context of shared decision-making with the patient and family/caregivers. Determining an estimate of the magnitude of 5-year SCD risk with risk calculators may provide additional information to inform ICD decision-making. In addition to the estimated risk of SCD, the age and size of the child also must be considered. In infants and preadolescent children with risk factors for SCD, the complications of ICD implantation may exceed the expected benefits. In such cases, the decision to place an ICD is individualized. Refer to UpToDate topics on pediatric HCM for additional details.