Abstract Body (Do not enter title and authors here):
Background
Left atrial appendage strain (LAAS) is a novel echocardiographic parameter that reflects atrial function. Emerging evidence suggests its prognostic relevance in atrial fibrillation, heart failure, and structural heart disease. However, its role in guiding procedural strategies and evaluating atrial appendage remodeling remains underexplored.

Objective
To assess whether reduced LAAS is associated with adverse atrial remodeling and increased energy requirements during direct current (DC) cardioversion.

Methods
A total of 62 patients were enrolled in the study, who underwent transesophageal echocardiography to exclude the presence of a clot. Afterward, patients underwent DC cardioversion using escalating biphasic energy levels of 100 joules, 200 joules, and 360 joules to restore a sinus rhythm. Left atrial appendage strain was studied, including reservoir (LAASr), conduit (LAAScd), and contraction strain (LAASct). Patients were stratified into two groups based on LAA reservoir strain (LAASr): Low LAASr <5% (n = 36) and high LAASr ≥5% (n = 26). Clinical and echocardiographic characteristics were compared between the two groups.

Results
Patients with LAASr <5% required significantly higher cardioversion energy (172 Joules vs. 121 Joules, p = 0.01), and demonstrated significantly reduced conduit -4.4% and contraction strain 2.6% ( p < 0.05). There was no significant difference in LA size, LV end diasolic volume and LV ejection fraction between groups.

Conclusions
The study showed atrial fibrillation patients with low left atrial appendage strain require higher energy levels for successful DC cardioversion, suggesting that LAASr may serve as a predictor of energy requirement in DC cardioversion for restoring sinus rhythm in AF patients.