Remodeling of the Left Atrium and the Possibility of Predicting Recurrences of Atrial Fibrillation in Various Variants of Sinus Rhythm Restoration

Abstract

OBJECTIVE: to compare the dynamics of left atrial remodeling in patients with AF with various CP recovery options and to identify the most reliable predictors of AF recurrence.
 MATERIALS AND METHODS: 153 patients with non-valvular AF lasting from 24 hours to 6 months were examined. All patients were divided into 3 groups depending on the type of cardioversion: the 1st group included 49 patients whose CP was restored against the background of drug therapy; the 2nd group included 57 patients after electro-pulse therapy (EIT); the 3rd group included 47 patients who underwent radiofrequency isolation of the pulmonary veins (RFI LV). All patients underwent ECHO-cardiographic examination (ECHO KG) at the time of AF, as well as on 1, 3, 5, 15 days and 6 months after CP recovery with an assessment of indexed indicators of linear left atrium size (LP), LP volume, LP function recovery time by the rate of peak A transmittal flow (TMF) and LP filling pressure in relation to E/E with the help of a fabric Doppler imaging.
 RESULTS: it was revealed that the absence of AF paroxysms in any variant of cardioversion for 2 weeks is a reliable predictor of maintaining CP after 6 months (p 0.001) and reducing the number of AF paroxysms for 6 months (p 0.001). Accordingly, relapses of AF during the first 2 weeks indicate an increase in their probability within 6 months [OR (risk ratio) = 15.37]. A significant relationship was found between the timing of recovery of LP function (peak A 0.5 m/sec) and recurrence of AF during 2 weeks and 6 months of follow-up (p 0.05). In patients after LV RF, the linear size and volume of LP significantly decreased in dynamics while maintaining CP in comparison with those who had AF relapses for 6 months (p 0.05). In patients after conservative cardioversion and RF ILV, LP filling pressure (E/E) significantly decreased after 14 days (p 0.05) in the absence of AF relapses and did not change significantly by 6 months of follow-up (p 0.05).While in the presence of repeated paroxysms of AF, this indicator did not change significantly by 6 months of follow-up. In the EIT group, no reliable dynamics of the estimated parameters of LP remodeling was found.
 CONCLUSIONS: The peak A 0.5 m/s measured by TMF on 1 day after the rhythm restoration is a reliable predictor of CP retention for 6 months in any variant of cardioversion (p 0.001). The absence of AF paroxysms within 2 weeks after CP recovery reduces the likelihood of their occurrence also within 6 months with any choice of cardioversion (p 0.001). In patients with CP recovery on the background of drug therapy and after RF ILV, the absence of recurrence of arrhythmia for 6 months is associated with a significant decrease in the size of LP (ILP and IOLP), (p 0.05). A decrease in LP filling pressure (E/E) 2 weeks after conservative cardioversion and LV RFI can be considered a reliable predictor of maintaining sinus rhythm by 6 months (p 0.05).