# Left atrial function of patients with atrial fibrillation undergoing thoracoscopic hybrid ablation

## TL;DR

Thoracoscopic hybrid ablation improves left atrial function in patients with atrial fibrillation, mainly due to rhythm restoration and reduced atrial volume.

## Contribution

This study is the first to investigate the effect of thoracoscopic hybrid ablation on left atrial function in patients with complex atrial fibrillation.

## Key findings

- Thoracoscopic hybrid ablation improved left atrial reservoir and contractile strain and reduced left atrial volume.
- Improvements in left atrial function were mainly due to rhythm restoration in patients with persistent atrial fibrillation.

## Abstract

Thoracoscopic hybrid ablation is an effective and safe rhythm control strategy for patients with complex forms of atrial fibrillation. Its effect on left atrial function has not yet been studied.

In a retrospective single-centre analysis of patients undergoing thoracoscopic hybrid ablation, the left atrial emptying fraction was calculated using the biplane modified Simpson method in the apical 2- and 4-chamber views on transthoracic echocardiography. Left atrial strain (reservoir, conduction and contractility) was quantified using dedicated software.

Sixty-seven patients were included (mean age 64 years, long-standing persistent atrial fibrillation in 69%, median atrial fibrillation history duration 64 months). At baseline, left atrial function and contractility were poor. The reservoir and contractile strain improved postprocedure compared to baseline [15 (standard deviation (SD): 8) and 17 (SD: 6); P = 0.013; 3 (SD: 5) and 4 (SD: 4), P = 0.008], whereas the left atrial volume indexed to the body surface area was reduced [51 ml/m2 (SD: 14) and 47 ml/m2 (SD: 18), P = 0.0024]. In patients with preoperative (long-standing) persistent atrial fibrillation and in patients with rhythm restoration, improvements in the emptying fraction, (reservoir and contractile) strain and the left ventricular ejection fraction were observed, whereas the left atrial volume decreased (P < 0.05).

In this cohort of patients with severely diseased left atria, improvement in left atrial contractility and in the emptying fraction after thoracoscopic hybrid ablation for atrial fibrillation in patients with persistent atrial fibrillation is mainly due to rhythm restoration. Interestingly, the procedure itself also results in improved left atrial reservoir strain and reversed left atrial remodelling by reducing left atrial volume.

Recent randomized data have shown that thoracoscopic hybrid atrial fibrillation (AF) ablation yields better rhythm outcomes than catheter ablation, without increasing complication rates [1].