Esophageal positions relative to the left atrium; data from 293 patients before catheter ablation of atrial fibrillation

Abstract

Aims: Three-dimensional rotational angiography (3DRA) of the left atrium (LA) and the esophagus is a simple and safe method for analyzing the relationship between the esophagus and the LA during catheter ablation of atrial fibrillation. The purpose of this study is to describe the location of the esophagus relative to the LA and mobility of the esophagus during ablation procedure.

Methods: From 3/2011 to 9/2015, 3DRA of the LA and esophagus was performed in 326 patients before catheter ablation of atrial fibrillation. 3DRAwas performed with visualization of the esophagus via peroral administration of a contrast agent. The positions of the esophagus were determined at the beginning of the procedure, for part of patients also at the end of procedure with contrast esophagography.

Results: The most frequent position is behind the center of the LA (91 pts., 31.9%) The least frequent position is behind the right pulmonary veins (27 pts., 9.4%). The average shift of the esophagus position was 3.36±2.15mm, 3.59±2.37mm and 3.67±3.23mm for superior, middle and inferior segment resp.

Conclusions: The position of the esophagus to the LA is highly variable. The most common position of the esophagus relative to the LA is behind the middle and left part of the posterior wall of the LA. The least frequently observed position is behind the right pulmonary veins. No significant position change of esophagus motion from before to after the ablation procedure in the majority (≥95%) of the patients was observed.

Keywords: 3D rotational angiography of the left atrium and esophagus; Atrioesophageal fistula; Catheter ablation of atrial fibrillation; Image integration; Position of esophagus to the left atrium; Shortterm mobility of the esophagus.

Copyright © 2017 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

Figures

Fig. 1

Acquisition of the 3DRA data and the segmentation of the 3D model of the left atrium and esophagus. A − a reduction in the cardiac output with rapid stimulation of the ventricles (right ventricular pacing at 220/min.) documented by a decrease in saturation and the record from the bedside monitor. B − raw data from the 3D rotational angiography of the left atrium with segmentation of the 3D model. The picture shows a section of raw data in three mutually perpendicular planes and a preview of the resulting 3D model in the left lateral view. The blue color shows the automatic evaluation of the left atrial cavity; the purple color shows the manually segmented esophagus. C and D – examples of an application of the 3D model of the left atrium with visualized esophagus during the isolation of the pulmonary veins (anteroposterior view). The twenty pole circular catheter is introduced into the RSPV, and the tip of the ablation catheter is in sight of the resulting line on the posterior wall of the left atrium. The tip of the ablation catheter is inside the esophagus model. D – for greater clarity, the model of the left atrium is hidden. E – the final model of the left atrium and esophagus in the left lateral view. We can see the left-sided pulmonary veins, base of the auricle and the esophagus (in purple) adjoined to the posterior wall of the left atrium. LA – left atrium, oeso – esophagus, RSVP – right superior pulmonary vein.

Fig. 2

A – methodology of the assessment of the esophageal position, B to F – examples of different positions of the esophagus in posteroanterior view, B – extremely left lateral position (A), C – left lateral position (B), D – middle position (C), E – right lateral position (D), F – extreme right lateral position (E).

Fig. 3

Methodology of the esophageal shift measurement. Measurement of the position of the esophagogram and 3D model of the esophagus. Green arrows show the measurement of the position of the esophagus at the beginning of procedure (3D model of the esophagus) relative to the nearest vertebra. Red arrows show the measurement of the position of the esophagus at the end of procedure (contrast esophagogram) relative to the nearest vertebra. Blue arrows show the measurement of the width of the esophagus at the beginning of the procedure (3D model of the esophagus), yellow arrows show the measurement of the width of the esophagus at the end of the procedure(esophagogram). Picture shows the small shift of the esophagus by 0.8 mm at the top position, by 2.6 mm at the central position and by 2.1 mm at the lower position.

Fig. 4

Graphs of esophageal position frequency.