Abstract
BACKGROUND: Atrial fibrillation (AF) is classified according to the amplitude of fibrillatory waves (f) into fine waves (fAF) and coarse waves (cAF). OBJECTIVES: To correlate the amplitude of f waves with clinical, laboratory, electrocardiographic, and echocardiographic variables that indicate a high risk of thromboembolism and to assess their impact on the success of electrical cardioversion (ECV). METHODS: Retrospective, observational study that included 57 patients with persistent non-valvular AF who underwent ECV. The maximum amplitude of f waves was measured in lead V1. cAF was defined when f ≥ 1.0mm and fAF when f < 1.0mm. The findings were correlated with the indicated variables. Values of p < 0.05 were considered statistically significant. RESULTS: cAF (n = 35) was associated with greater success in ECV (94.3% vs. 72.7%, p = 0.036) even after adjusting for variables such as age and BMI (p = 0.026, OR = 11.8). Patients with fAF (n = 22) required more shocks and more energy to revert to sinus rhythm (p = 0.019 and p = 0.027, respectively). There was no significant association between f-wave amplitude and clinical, echocardiographic, and laboratory parameters. CONCLUSIONS: The amplitude of f wave was not associated with echocardiographic, clinical and laboratory parameters that indicate a high risk of thromboembolism. cAF was associated with a higher chance of success reverting to sinus rhythm employing ECV. A greater number of shocks and energy were required for reversion to sinus rhythm in patients with fAF.