Changes in left atrial function in patients undergoing cardioversion for atrial fibrillation: relevance of left atrial strain in heart failure

Background Left atrial (LA) reservoir strain provides prognostic information in patients with and without heart failure (HF), but might be altered by atrial fibrillation (AF). The aim of the current study was to investigate changes of LA deformation in patients undergoing cardioversion (CV) for first-time diagnosis of AF. Methods and results We performed 3D-echocardiography and strain analysis before CV (Baseline), after 25 ± 10 days (FU-1) and after 190 ± 20 days (FU-2). LA volumes, reservoir, conduit and active function were measured. In total, 51 patients were included of whom 35 were in SR at FU-1 (12 HF and preserved ejection fraction (HFpEF)), while 16 had ongoing recurrence of AF (9 HFpEF). LA maximum volume was unaffected by cardioversion (Baseline vs. FU-2: 41 ± 11 vs 40 ± 10 ml/m2; p = 0.85). Restored SR led to a significant increase in LA reservoir strain (Baseline vs FU-1: 12.9 ± 6.8 vs 24.6 ± 9.4, p < 0.0001), mediated by restored LA active strain (SR group Baseline vs. FU-1: 0 ± 0 vs. 12.3 ± 5.3%, p < 0.0001), while LA conduit strain remained unchanged (Baseline vs. FU-1: 12.9 ± 6.8 vs 13.1 ± 6.2, p = 0.78). Age-controlled LA active strain remained the only significant predictor of LA reservoir strain on multivariable analysis (β 1.2, CI 1.04–1.4, p < 0.0001). HFpEF patients exhibited a significant increase in LA active (8.2 ± 4.3 vs 12.2 ± 6.6%, p = 0.004) and reservoir strain (18.3 ± 5.7 vs. 22.8 ± 8.8, p = 0.04) between FU-1 and FU-2, associated with improved LV filling (r = 0.77, p = 0.005). Conclusion Reestablished SR improves LA reservoir strain by restoring LA active strain. Despite prolonged atrial stunning following CV, preserved SR might be of hemodynamic and prognostic benefit in HFpEF. Graphical abstract

Characteristics of left atrial strain in patients with atrial fibrillatio after cardioversion

The aim of the study – to evaluate the parameters of left atrial myocardial strain in patients with atrial fibrillation who underwent electrical and drug cardioversion.Materials and methods. The study included 118 patients of the University Clinical Hospital No 1 of the First Sechenov Moscow State Medical University. The analysis was carried out in three groups of patients: group 1 (n=54) – patients with atrial fibrillation who underwent electrical cardioversion; group 2 (n=31) – patients with atrial fibrillation who underwent drug cardioversion; group 3 (n=43) – patients without a history of atrial fibrillation. The clinical and anamnestic data of the medical history of each patient, as well as ultrasound indicators were evaluated: global strain of the left atrial, the values of negative peaks as a reflection of the left atrial systole and the values of positive peaks as a reflection of the filling of the left atrium, LASI – the left atrial stiffness index.Results. The analysis showed that left atrial strain in patients with atrial fibrillation were reduced in all analyzed parameters: negative strain peaks (-9.00 vs. -12.6 in the control group, p<0.001), positive strain peaks (12.6 vs. 14.6 in the control group, p<0.001), global left atrial strain (21.5 in the atrial fibrillation group vs. 27.3 in the control group, p<0.001). Left Atrial Stiffness Index (LASI) was significantly higher in patients with a stopped episode of atrial fibrillation (0.50 vs. 0.40, p=0.006).Conclusions. The indicators of left atrial strain were significantly reduced, and the left atrial stiffness index was significantly increased both in the group with electrical cardioversion and in the group with drug-induced cardioversion, compared with patients with similar cardiovascular pathologies, but without a history of atrial fibrillation episodes.