PREDICTION OF SINUS RHYTHM MAINTENANCE AFTER RADIOFREQUENCY ABLATION IN PATIENTS WITH ATRIAL FIBRILLATION USING SPECKLE TRACKING ECHOCARDIOGRAPHY AND DYNAMICS OF LEFT ATRIAL STRUCTURAL AND FUNCTIONAL PARAMETERS
Aim. To evaluate the dynamics of left atrial volume (LAV), strain (S) during the reservoir phase and strain rate (SR) in patients with paroxysmal and persistent atrial fibrillation (AF), scheduled for catheter radiofrequency ablation (RFA), as well as to compare the predictive value of S and SR as a marker of maintaining sinus rhythm. Material and methods. A total of 19 patients (men, 11; women, 8) aged 62±10,7 years with AF were included in the study, 13 (67%) of whom had persistent AF, while 6 patients (33%) had paroxysmal AF. Two-dimensional and speckle tracking echocardiography (EPIQ 7, Philips) were performed in all patients before ablation and 12 months after RFA. Results. The patients were divided into 2 groups: group 1 - no recurrent AF after RFA (n=12; 63%); group 2 - recurrent AF after RFA (n=7; 37%). According to 2D echocardiography, the baseline values of LAV and LAV index (LAVI) did not significantly differ between groups 1 and 2: 56,0±12,6 ml and 52,0±23,2 ml (p=0,78); 28,0±7,8 ml/m<sup>2</sup> and 25,1±13,6 ml/m<sup>2</sup> (p=0,85), respectively. The initial S values of the LA in the four-chamber (4C-) and two-chamber (2C-) apical views in group 1patients were higher than in those from group 2: 4C-S, 34,3±9,9% and 16,9±4,4% (p=0,0008); 2C-S, 29,2±8,3% and 14,5±4,4% (p=0,0011), respectively. Baseline SR values were higher in group 1 patients compared with group 2 in 4C- and 2C-views: 4C-SR, 2,36±0,37 <sup>s-1</sup> and 1,39±0,50 <sup>s-1</sup> (p=0,0013); 2C-SR 2,09±0,39 <sup>s-1</sup> and 1,4±0,53 <sup>s-1</sup> (p=0,0053), respectively. The LAV in group 1 became significantly less after RFA than its initial levels: 56,0±12,6 ml and 47,0±12,1 ml (p=0,008). The LAVI also significantly decreased 12 months after RFA as follows: 28,0±7,8 ml/m<sup>2</sup> and 22,6±8,3 ml/m<sup>2</sup> (p=0,02). In group 2, there was no decrease in either LAV or LAVI after 12 months: LAV, 52,0±23,2 ml and 54,0±12,1 ml (p=1,0); LAVI, 25,1±13,6 ml/m<sup>2</sup> and 30,9±7,6 ml/m<sup>2</sup> (p=0,3). In group 1, there was no significant change in LA S 12 months after RFA: 4C-S, 34,3±9,9% and 30,3±9,6% (p=0,287); 2C-S, 29,2±8,3% and 28,9±9,1% (p=0,82). In group 2, LA S levels in 4C- and 2C-views did not significantly change depending on the performed RFA procedure: 4C-S, 16,9±4,4% and 17,4±6,2% (p=0,12); 2C-S, 14,5±4,4% and 16,5±6,8% (p=1,0). According to the ROC analysis, the optimal cut-off values for baseline 4C-SR (1,8 <sup>s-1</sup> (AUC=0,958)), 2C-SR (1,75 <sup>s-1</sup> (AUC=0,899)), 4C-S (20,7% (AUC=0,976)), and 2C-S (19,2% (AUC=0,964)) were reliable individual predictors of sinus rhythm maintenance. Conclusion. A stable sinus rhythm 12 months after the RFA was maintained in patients with higher baseline LA S and SR levels. The baseline LA S and SR values have a high predictive value for AF recurrence in patients after RFA. In patients with effective RFA, LAV and LAVI decreased without changing the S and SR. There was no effect of LA reverse remodeling and improvement in LA S values in patients with recurrent AF after RFA.