Evaluation of the Clinical Phenotype and Follow-up of Children with ‘Non sustained’ Ventricular Tachycardia Detected on 24-hour Rhythm Holter

Objective: Non-sustained ventricular tachycardia (NSVT) is an important arrhythmic finding in pediatric patients, with varying clinical implications based on the presence of structural heart disease. This study aimed to evaluate the clinical characteristics, follow-up, and management of children diagnosed with NSVT detected on 24-hour Holter monitoring. Methods: A retrospective analysis was conducted on 22 pediatric patients (9 males, 13 females) aged 2.5–17 years, who were diagnosed with NSVT between 2015 and 2023. Patients with sustained VT, channelopathies, or electrolyte-related prolonged QTc were excluded. Echocardiography, electrocardiography, and Holter monitoring were performed for all patients. Statistical analyses were conducted using SPSS 26.0, with significance set at p<0.05. Results: Monomorphic NSVT was observed in 14 patients (64%), while polymorphic NSVT was found in 8 patients (36%). The mean VT rate was 161.2±18.7 bpm, with polymorphic VT demonstrating a significantly higher rate (175.3±4.4 bpm) than monomorphic VT (153.3±4.6 bpm) (p=0.003). The prematurity index was significantly lower in polymorphic VT (0.75±0.03) than in monomorphic VT (1.1±0.03) (p<0.001). Additionally, QTc was longer in polymorphic VT (463.5±5.1 ms vs. 425.4±6.5 ms, p=0.004). Structural heart disease was present in 50% of cases, with polymorphic VT being predominantly associated with cardiomyopathies (dilated, hypertrophic, and non-compaction). Only three patients (14%) were symptomatic, and all symptomatic patients had structural heart disease. All patients with underlying cardiac abnormalities were treated with beta-blockers, primarily propranolol, while those with normal echocardiography were followed without medication. No adverse effects, syncope, or mortality were observed during follow-up. Conclusion: NSVT in pediatric patients should be carefully evaluated, particularly in the presence of structural heart disease. While monomorphic NSVT in structurally normal hearts appears benign, polymorphic NSVT is strongly associated with cardiomyopathies, necessitating medical therapy and close monitoring. Individualized management based on echocardiographic findings and arrhythmic characteristics is essential for optimizing patient outcomes.