Non-sustained Ventricular Tachycardia in Children and Adult Congenital Heart Disease: Optimal Duration and Clinical Significance.

The frequency and clinical significance of non-sustained ventricular tachycardia (NSVT) detected on ambulatory monitors in pediatric and congenital heart disease (CHD) patients (pts) has not been thoroughly investigated. This study aims to examine the prevalence of NSVT, analyze the presence of associated cardiovascular disease, and describe changes in management. We performed a retrospective cohort study of all pts evaluated in cardiology clinic at Cleveland Clinic who were found to have NSVT on ambulatory patch monitors (2017-2023). Among 2805 pts, 172 (age 29 ± 14, range: 3-81) had NSVT yielding a prevalence of 6% and a monitoring duration of 7.5 ± 5.5 days. Cardiac diagnoses included: 57% CHD, 26% structurally normal hearts, 8% cardiomyopathy, 6% connective tissue disorder, and 3% channelopathy. Mean day of NSVT detection was 4.3 ± 3.7 days without significant difference amongst the various underlying cardiac diagnoses. Management changes were made in 52 pts: medication change in 43, loop recorder placement in 4, and cardiac defibrillator placement in 5. Five pts died with 1 suspected sudden cardiac death. The likelihood of NSVT detection increased with longer monitoring duration with only 55% of cases detected at 2 days. In a multivariable model, monitoring duration but not underlying diagnosis, age, monitor indication, or single ventricle status, was associated with the likelihood of NSVT detection. While NSVT is relatively uncommon, it is increasingly detected in pediatric and CHD pts with longer monitoring durations, regardless of the underlying cardiac condition. Although medical management changes based on monitor findings were frequent, sudden death was rare.