Arrhythmic Burden and Ambulatory Monitoring of Pediatric Patients with Cardiomyopathy.

BACKGROUND: Pediatric patients with cardiomyopathy (CM) are at risk for sudden cardiac death (SCD), likely driven by arrhythmic etiologies.
OBJECTIVES: Describe arrhythmia burden and Holter utility in pediatric CM including: hypertrophic CM (HCM), dilated CM (DCM), and restrictive CM (RCM).
METHODS: Retrospective cohort study of patients <21 years with CM. Patient demographics, arrhythmic history, and genetic status were reviewed including outcomes of death, aborted SCD, and device shocks. Holter findings were analyzed over the prior 5 years including clinically significant findings and resulting changes to management. Analysis for the composite outcomes of death, aborted SCD, and appropriate shock were performed using logistic regression with backward elimination.
RESULTS: One hundred and forty-six patients were included: 83 HCM, 54 DCM, and nine RCM (mean 13 ± 6 years). A total of 23% of patients had defibrillators. There were six deaths (two SCD), four patients with appropriate device therapies, and four aborted SCD episodes. In total, 305 Holter monitors were reviewed. Six Holters had significant findings, all nonsustained ventricular tachycardia. Two Holters resulted in changes in management, both defibrillator implantations. Twelve patients had one or more of the conditions defining the composite outcome. Using logistic regression, clinical history of ventricular arrhythmia, frequent premature ventricular complexes, and CM type were included as potential independent predictors in the final model and clinical ventricular arrhythmia and RCM disease were associated with the composite outcome.
CONCLUSIONS: SCD and device therapies were relatively rare. Routine Holter screening rarely demonstrated significant findings or changed clinical care. Clinical history of ventricular arrhythmia was associated with poor clinical outcome. ©2016 Wiley Periodicals, Inc.