Left atrial booster-pump function as a predictive parameter for atrial fibrillation in patients with severely dilated left atrium

Abstract

Background: Left atrial (LA) dimension ≥50 mm had approximately four times the risk of developing atrial fibrillation (AF). The aim of this study was to investigate whether the application of clinical and echocardiographic parameters could differentiate between the patients having severely dilated left atrium with and without AF.Methods: This retrospective cross-sectional study enrolled consecutive patients with LA dimension ≥50 mm and divided them into three groups: no AF (no-AF), paroxysmal AF (PAF) and non-paroxysmal AF (non-PAF) groups. For PAF and non-PAF groups, all patients underwent radiofrequency ablation, and the echocardiographic parameters were obtained on the next day after ablation.Results: Our study population comprised 160 patients, including 80, 53, and 27 patients in the non-AF, PAF and non-PAF groups, respectively. The no-AF group had a significantly higher body mass index (kg/m 2 ) (29.31±6.27, 27.58±4.12 and 26.57±2.81, P=0.01), and a higher prevalence of diabetes mellitus (DM)[31 (38.80%), 13 (25.00%) and 4 (14.80%), P=0.01] and hypertension [67 (83.80%), 34 (65.40%), and 19 (70.40%), P=0.04], but a lower prevalence of rheumatic heart disease (RHD) [3 (3.80%), 6 (11.50%) and 5 (18.50%), P=0.02] and sick sinus syndrome [0 (0.00%), 6 (11.50%) and 4 (14.80%), P=0.045].Echocardiographic studies showed that the non-AF group had significantly smaller LA minimal volume index (24.89±9.74, 34.06±19.38 and 42.83±17.44 mL/m 2 , P<0.01), higher LA emptying fraction (51.99%±13.97%, 38.40%±15.96% and 33.89%±10.73%, P<0.01), longitudinal strain (23.87%±7.72%, 17.11%±8.52% and 12.38%±4.28%, P<0.01) and strain rate than the AF groups. The multivariate analysis showed that the late diastolic component of LA strain rate was the only independent factor associated with the presence of AF (odds ratio, 21.69; 95% CI, 9.77-48.13, P<0.01).Conclusions: LA function plays an important role in the absence of AF in patients with LA dimension ≥50 mm; the late diastolic component of LA strain rate was the only independent variable on multivariate analysis.

Đặc Điểm Siêu Âm Tim Đánh Dấu Mô Nhĩ Trái Ở Bệnh Nhân Tăng Huyết Áp Có Rung Nhĩ Cơn

“…Tuy nhiên, nếu rung nhĩ diễn ra quá lâu sẽ dẫn đến những thay đổi mang tính cố định ở cấu trúc cơ của nhĩ trái như xơ hoá, sợi hoá và lâu dần sẽ dẫn đến giãn nhĩ như một cơ chế đáp ứng bù trù. Khi có rung nhĩ thì chức năng trữ máu và dẫn máu vẫn còn duy trì, tuy nhiên chức năng co bóp của nhĩ trái đã bị mất đi [7]. Khi có hồi phục lại nhịp xoang thì chức năng này có thể quay trở lại và có thể suy giảm.…”

Modern methods of echocardiographic assessment of the functional status of the left atrium in atrial fibrillation

“…Достаточно изучено, что определенный сегмент миокарда ЛП имеет свои нормальные значения деформации и скорости деформации. Задняя стенка ЛП подвержена наименьшей деформации, вероятнее всего, это связано с впадением легочных вен и их плотной фиксацией [30], нижняя стен-Рис. 4.…”

From Left Atrial Dimension to Curved M-Mode Speckle-Tracking Images: Role of Echocardiography in Evaluating Patients with Atrial Fibrillation

“…This result suggests that LA dysfunction plays a more pivotal role than LA enlargement in the development of AF. Recently, our group demonstrated that LAEF, , LASr, pLASRr, and pLASRct were associated with the occurrence of AF, and multivariate regression analysis revealed that pLASRct was the only independent factor associated with the absence of AF in those with LAD 50 mm [ 112 ]. Atrial booster pump function represents the inherent contractility of the LA myocardium.…”