Auto left atrial strain by speckle tracking echocardiography and auto left atrial volumes by 3D transthoracic echocardiography after electrical cardioversion for atrial fibrillation
Authors: Karapedi E , Tsagaropoulos A , Antoniades K , Aqeel I , Koutsogiannaki E , Peteinaki A , Hamodraka E , Tsoukas A 
Published: June 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Introduction
We have evidence that left atrial dysfunction and stunning occur after electric cardioversion for atrial fibrillation (CAF). Additionally, after successful cardioversion to sinus rhythm, a dissociation between electrical and mechanical recovery may be observed. Traditional pulsed Doppler and tissue Doppler imaging parameters demonstrate reduced atrial contractility immediately after cardioversion. Improvement in atrial function occurs within the first 4 weeks after sinus rhythm is restored. Recent advances in the assessment of myocardial function have facilitated the direct measurement of auto left atrial strain using speckle tracking echocardiography, and auto left atrial volumes measurements using dynamic heart model modern 3D transthoracic echo logistics.

Purpose
Aim of this study was to determine whether auto left atrial strain (auto LAs) by speckle tracking echocardiography, and auto left atrial volumes measurements, auto left atrial volume indices calculations (auto LAVI), could be used to evaluate global left atrial function and when a main improvement occurs after electrical cardioversion for CAF.

Methods
Auto LAs was measured from transthoracic echocardiography in 25 patients with CAF who had been cardioverted to sinus rhythm and followed up for 4 weeks, and in a cohort of 25 healthy individuals. Left atrial contractile strain (LACTS), conduit strain (LACDS) and reservoir strain (LARSS) were measured. Conventional measures of atrial function derived from transmitral pulsed wave doppler (PW) and tissue doppler imaging (TDI) of lateral mitral annulus were included, such as A wave velocity, A wave velocity time integral, A' wave velocity and A' velocity time integral.

Results
Immediately after cardioversion all PW, TDI and all three auto LAs parameters were significantly lower than in controls. On the other hand, auto LAVI was significantly higher in patients compared to controls immediately after cardioversion Atrial function was improved over time with maximal change observed 4 weeks after cardioversion and restoration to sinus rhythm. Auto LAs parameters were significantly higher in the group of patients. Auto LA volumes and auto LAVI with dynamic heart model logistics were lower in the same group, but with no statistical significance. Three patients with the lowest auto LAs values immediately after cardioversion, suffered recurrence of atrial fibrillation during the 4 weeks follow up.

Conclusions
Although left atrial electrical function is immediately restored after cardioversion in CAF patients, a persistent degree of atrial dysfunction remains for up to 4 weeks. This difference could explain the increased propensity for these patients to develop recurrent atrial fibrillation. Additional this dysfunction could indicate the longer-term use of antiarrhythmic and antithrombotic medication in the CAF cohort.