Effect of flecainide on complex ventricular arrhythmogenesis: insights from the prospective UNIFLECA study
S Kotoulas, D Tsiachris, I Doundoulakis, A Kordalis, P Tsioufis, A Laina, M Botis, E Kallergis, G Leventopoulos, C TsioufisAbstract
Background
Persistent high burden of premature ventricular contractions (PVCs) may lead to myocardial dysfunction and symptomatic deterioration. Although catheter ablation is the therapy of choice for high-burden or symptomatic PVCs, antiarrhythmic drugs remain an essential treatment alternative, particularly for patients who decline catheter ablation. The occurrence of duplets and non-sustained ventricular tachycardia (NSVT) is associated with an increased risk of arrhythmogenic cardiomyopathy and often indicate an unstable ventricular substrate.
Purpose
To assess the impact of flecainide on the complexity and progression of ventricular ectopy, focusing on changes in duplets and NSVT occurrence before and after therapy.
Methods
This subanalysis included 97 consecutive patients from the prospective multicenter UNIFLECA study, all declining catheter ablation and treated with flecainide for idiopathic PVCs and documented high ectopic burden (>5%). Patients with structural heart disease were excluded after complete evaluation, including cardiac magnetic resonance imaging (CMR). The presence of duplets and NSVT was recorded by 24-hour Holter monitoring before and after initiation of slow-release flecainide. Changes were expressed as categorical variables, and transitions from NSVT to duplets were also documented.
Results
At baseline, 48 patients (58.5%) exhibited ventricular duplets and 19 patients (23.2%) had NSVT. After flecainide initiation, the number of patients with duplets decreased to 29, with 26 patients (27%) showing complete resolution. The number of patients with NSVT fell to 6, corresponding to a 68.4% reduction. Among those with baseline NSVT, 10 patients (52.6%) achieved full suppression, and 2 patients (10.5%) demonstrated conversion from NSVT to isolated duplets, reflecting a marked simplification of arrhythmic complexity. Overall, 28 patients (28.9%) experienced complete or partial resolution of complex ventricular ectopy under flecainide therapy.
Conclusions
Flecainide therapy led not only to a reduction in PVC burden but also to a significant decrease in arrhythmia complexity, suppressing NSVT and duplets and simplifying the ventricular ectopic pattern. The above support its use as a safe and effective therapeutic option for patients without structural heart disease that decline catheter ablation even in the context of complex idiopathic ventricular arrhythmias.Flecainide on Complex Arrhythmogenesis