Background: Radiofrequency ablation (RFA) of atrial fibrillation (AF) has become an effective treatment. Despite of constant improvement of diagnostic and treatment technology of AF, the recurrence of AF after RFA is still ongoing problem. Prediction of recurrence after RFA for AF is important for establishment of treatment strategies. The aim of this study was to assess clinical usefulness of LA vortex flow analysis for predicting of AF recurrence after RFA. Methods: A total of 21 patients of AF scheduled RFA underwent 2D transthroacic and transesophageal echocardiography with intravenous unfusion of Definity® and imaged at a mechanical index of 0.4 - 0.6 in the horizontal, longitudinal, and long cardiac views before RFA. The two component of the velocity vector were estimated by particle image velocimetry using Omega flow®. We identified the morphology and pulsatility of the LA vortex flow from all patients. Six months later after RFA, 10 patients with recurrence of AF (recurrence group) and 11 patients without recurrence (non-recurrence group) were classified into two groups. The LA vortex flow parameters were compared between two groups.
Results: There were no significantly different in baseline characteristics and conventional echocardiographic parameters. In LA vortex flow analysis, vortex length (VL), vortex width (VW), and vortex relative strength (VRS) at long cardiac view were significantly higher in recurrence group than non-recurrence group (VL, 0.677 ± 0.159 vs. 0.548 ± 0.119, p = 0.013; VW, 0.414 ± 0.079 vs. 0.319 ± 0.053, p = 0.005; VRS, 0.366 ± 0.065 vs. 0.301 ± 0.068, p = 0.043). Relative strength was not significantly different between two groups but tended to be lower in recurrence group (1.650 ± 0.336 vs. 1.760 ± 0.393, p = 0.086).
Conclusions: This study showed feasibility of clinical usefulness of LA vortex flow analysis for predicting of AF recurrence after RFA, which has the potential benefit for establishment of treatment stratiges in patients with AF.
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