Pediatric Left Ventricular Non-compaction: A Single-center Experience from Anatolia

Objective: To describe the phenotypic diversity, arrhythmia burden, and short-to-medium term clinical outcomes in pediatric left ventricular non-compaction (LVNC) cases, in light of a single-center experience from Anatolia. Material and Methods: Sixteen children diagnosed with LVNC and followed at the Pediatric Cardiology Department of Ordu University Training and Research Hospital between December 2017 and July 2025 were retrospectively evaluated. Demographic characteristics, presenting symptoms, transthoracic echocardiography (TTE) and cardiac magnetic resonance (CMR) findings, 12-lead electrocardiogram and 24-hour Holter results, and treatments were recorded. The diagnosis was made based on TTE criteria and confirmed by CMR in all cases. Genetic analysis results were recorded for the cases. Results: The median age at diagnosis was 7 years (range: 15 days-16 years), and 68.8% of the patients were male; the median follow-up was 33 months (range: 6-82). At presentation, 62.5% of cases were asymptomatic, whereas heart failure was observed in 37.5% of cases. The phenotypic distribution was predominantly isolated LVNC (n=8, 50%); among the non-isolated forms, the dilated type (n=5) was most common, while hypertrophic (n=1), restrictive (n=1), and mixed types (n=1) were also observed. The overall arrhythmia rate was 37.5% (n=6): ventricular tachycardia (VT) was observed in two cases, Wolff-Parkinson-White associated supra-VT was observed in two cases, and frequent ventricular extrasystoles were observed in two cases. Two cases required intervention: sympathetic denervation in one case (diagnosed with catecholamine-sensitive polymorphic VT) and implantation of an implantable cardioverter-defibrillator in the other. Three patients (18.8%) died during follow-up, and the fatalities were concentrated among the dilated and mixed-restrictive subtypes. Pathogenic variants were detected in two of the three cases that underwent genetic testing: PLEKHM2 in two cases and RYR2 in one. The RYR2 carrier had catecholaminergic polymorphic VT. Acetylsalicylic acid and beta-blockers formed the basis of medical management; antiarrhythmics and advanced interventions were applied in selected cases. Conclusion: This single-center pediatric series shows that the isolated form is relatively dominant, but clinical risk changes depending on the phenotype. Arrhythmias are common, and dilated and mixed-restrictive forms have a less favorable course. Confirming the TTE-based diagnosis with CMR and closely monitoring pediatric cases based on phenotype-rhythm findings may facilitate accurate classification and risk management.