Elsevier

JACC: Cardiovascular Imaging

Volume 2, Issue 9, September 2009, Pages 1039-1047
JACC: Cardiovascular Imaging

Original Research
Evaluation of Left Atrial Degeneration for the Prediction of Atrial Fibrillation: Usefulness of Integrated Backscatter Transesophageal Echocardiography

https://doi.org/10.1016/j.jcmg.2009.03.021Get rights and content
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Objectives

The purpose of this study was to elucidate the usefulness of integrated backscatter (IBS) transesophageal echocardiography (TEE) for the evaluation of atrial degeneration and clarify whether atrial degeneration predicts the occurrence of atrial fibrillation (AF).

Background

One of the causes of AF is pathological degeneration of the left atrium (LA). However, there is no appropriate method to evaluate degeneration of the LA in the clinical setting.

Methods

The IBS images were acquired with TEE with a 4- to 7-MHz transducer. The IBS values were calculated as the average power of the backscattered signal from regions of interest (ROI). In the pathological study, we measured IBS values of 21 left atrial specimens obtained from 10 autopsied hearts. Relative interstitial area in the ROI was automatically calculated by a personal computer. In the clinical study, we measured IBS values of the entire LA wall at 5-mm intervals (except the posterior wall) in 42 patients (18 non-AF patients, 14 paroxysmal AF patients, and 10 chronic AF patients). Each IBS value was color-coded to construct 3-dimensional maps.

Results

There was a weak correlation between the relative interstitial area and IBS values (r = 0.45, p = 0.038). Average corrected IBS values of total voxels in color-coded maps in the AF group (24.4 ± 6.4 dB) and the paroxysmal AF group (23.9 ± 9.6 dB) were significantly greater than those in the non-AF group (15.6 ± 7.4 dB, p = 0.007), whereas there was no significant difference in LA diameter between the paroxysmal AF group (39.4 ± 6.5 mm) and the non-AF group (36.7 ± 5.5 mm).

Conclusions

With IBS-TEE, we can identify an increase in atrial degeneration that might predict the occurrence of AF before LA dilation.

Key Words

atrial fibrillation
integrated backscatter
tissue characterization
transesophageal echocardiography

Abbreviations and Acronyms

AF
atrial fibrillation
ANP
atrial natriuretic peptide
BNP
brain natriuretic peptide
cIBS
corrected integrated backscatter
IBS
integrated backscatter
LA
left atrium
LAA
left atrial appendage
PAF
paroxysmal atrial fibrillation
ROI
region-of-interest
TEE
transesophageal echocardiography

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