P-Wave Indices for Risk Assessment of Atrial Fibrillation in Chagas Disease

Abstract

Background: Studies analyzing atrial activation on electrocardiograms (ECGs) have usually highlighted P-wave duration, P-wave dispersion, PR interval, P/PRi ratio, and atrial activation time (AAT). Although these indices can be predictors of atrial fibrillation (AF) in different clinical contexts, no study has analyzed them in the context of Chagas disease (CD). Objectives: To evaluate the following electrocardiographic indices as predictors of AF in CD: P-wave duration, AAT, P-wave dispersion, PR Interval, and P/PRi ratio. Methods: This retrospective study examined ECGs of CD patients who had been monitored for at least 10 years and analyzed the progression of five electrocardiographic indices over time in patients with and without AF.Results: Of the 42 patients with CD included in the study, 13 experienced AF ("with AF" group) and 29 did not ("without AF"). The mean time elapsed between the first and the second ECGs analyzed was 20.55±7.54 years. While the P/PRi ratio was not different between the two groups at the time of the first ECG, it decreased from 0.68±0.11 to 0.57±0.11 in the "with AF" group and was significantly lower than the "without AF" group at the time of the second ECG (p=0.03). There were no statistically significant differences in the other parameters studied.Conclusions: In our study, only the P/PRi ratio was shown to predict the onset of paroxysmal AF, with lower values predicting the occurrence of this arrhythmia.