Congenital LQTS – Clinical Practice in Children’s Clinical University Hospital of Latvia

Objectives* Long QT Syndrome (LQTS) is a congenital cardiac channelopathy with a broad spectrum of manifestations, ranging from asymptomatic cases to syncope, life-threatening ventricular arrhythmias, and sudden cardiac death. This study highlights the prevalence of LQTS, genetic variants, family history, clinical test results and the therapies administered in the pediatric population of Latvia Materials and Methods From January 2010 to November 20, 2024, cases with a genetic or clinical diagnosis of LQTS were reviewed. The analysis included demographic and clinical data, family history, electrocardiographic (ECG) and echocardiographic findings, and treatment modalities. Results In our centre 31 cases with proven LQTS mutation, 4 more patients with high suspicion and clinical diagnosis of LQTS, waiting for genetical testing results were selected to this study. Demographic data: 12 ( 34.3 %) females, 23 ( 65.7%) males. Median age at the first cardiologist visit was 10 years ( SD 4.7). Genetical testing showed 62.9 % ( N – 22) patients has LQTS type 1, 8.6 % ( N- 3 ) diagnosed with type 2 LQTS, 1 – with type 3. Also more rarer types : 5 and 6 were found – 1 patient of each. 2 patients refused of genetical testing, 1 got VUS. Median longest registered QTc was 490 ms ( SD 36.1 ms) with interval 447 – 600 ms. 40 % (14) patients presented with cardiac symptoms: syncope ( 9), sudden cardiac death ( 4). Almost everyone recieve beta blocker treatment, except for those who refuses of any kind therapy. Conclusions Although LQTS is a rare disease, in the Latvian population, which includes only 356,000 children, these patients are identified, recognized, and successfully treated. Importantly, we also encounter very rare types, described in the literature as occurring in < 1% of cases. Over recent years, diagnostics for these patients have improved, with more cases being identified annually