Abstract 3063: Evaluation of the Left Atrial Degeneration using Integrated Backscatter Transesophageal Echocardiography for the Prediction of Atrial Fibrillation
Background: It is recognized that one of the causes of atrial fibrillation (AF) is pathological degeneration of the left atrium (LA). However, there has not been an appropriate noninvasive method to evaluate degeneration of the LA in the clinical setting.
Method: IB images were acquired with transesopageal echography (TEE) using a 4 to 7 MHz transducer for all studies. IB values were calculated as the average power of the backscattered signal from regions of interest (ROI). In the pathological study, we measured IB values of 21 left atrial specimens obtained from 5 autopsied hearts. Tissue was stained with hematoxylin and eosin and Masson’s trichrome. Percentages of interstitial degenerated area in ROI were automatically calculated by a personal computer. In the clinical study, we measured IB values of entire free wall of the LA at every 5mm in 32 patients (13 non-AF patients, 10 paroxysmal AF patients and 9 Chronic AF patients). Each IB value was color-corded to construct three dimensional images.
Result: There was a significant correlation between the percentages of interstitial area and IB values (r=0.45, p=0.038). IB values of the LA were significantly higher in the patients with than without AF (27.7 ± 4.2 versus 18.6 ± 6.2, p <0.0001) and also significantly higher in paroxysmal AF patients than non AF patients (27.3 ± 4.7 versus 18.6 ± 6.2, p=0.002), whereas no significant difference between left atrial diameter of paroxysmal AF patients and non AF patients (40 ± 6.3 versus 38.2 ± 5.1, p=0.46).
Conclusion: Using IB-TEE, we can easily and noninvasively identify an increase in interstitial fibrosis in the LA in patients with AF and may predict AF before LA dilation.