Frequency of Idiopathic Left Ventricular Tachycardia in Patients with Narrow Complex Tachycardia at a Tertiary Care Hospital: A Cross-Sectional Study

Objectives: To assess the frequency of idiopathic left ventricular tachycardia (ILVT) among patients presenting with narrow complex tachycardia at a tertiary care hospital. Methodology: This cross-sectional descriptive study was conducted at the Cardiac Electrophysiology Department, Hayatabad Medical Complex, Peshawar, from August 1, 2022, to August 1, 2023. A total of 1200 consecutive patients with narrow complex tachycardia were included in the analysis. Data were collected on demographic characteristics, clinical presentation, electrocardiographic findings, and results from electrophysiological studies. ILVT was diagnosed based on characteristic electrocardiogram (ECG) features, including right bundle branch block (RBBB) and left axis deviation (LAD), with confirmation from a positive response to verapamil administration. Results: Out of 1200 patients presenting with narrow complex tachycardia, 40 (3.33%) were diagnosed with ILVT. The majority of ILVT patients were male (75%), with a mean age of 34.8 ± 10.2 years. Among the ILVT cases, 95% presented with the posterior fascicular form. All ILVT patients exhibited narrow complex tachycardia with a QRS duration of less than 140 ms. Verapamil therapy was effective in all patients, with 35 (87.5%) undergoing successful catheter ablation. No recurrences were observed during a 12-month follow-up period. Conclusion: ILVT was identified in 3.33% of patients with narrow complex tachycardia, with a notably higher prevalence among younger males. The posterior fascicular variant was the most commonly observed form. Both verapamil and catheter ablation proved to be highly effective in managing ILVT, leading to favorable short-term outcomes. Further research is necessary to explore the long-term prognosis and investigate potential genetic factors that may contribute to the pathophysiology of ILVT.