Left atrial pathological degeneration assessed by integrated backscatter transesophageal echocardiography as a predictor of progression to persistent atrial fibrillation: Results from a prospective study of three-years follow-up

We measured IBS values of the entire LA wall at 5？mm intervals (except the posterior wall) in 27 patients with paroxysmal AF and evaluated progression to persistent AF for three years. IBS values were acquired with transesophageal echocardiography (TEE) using a 4–7？MHz transducer. IBS values were calculated as the average power of the backscattered signal from regions of interest (ROI). Each IBS value was color-coded to construct three dimensional maps.Average IBS values of total voxels in color-coded maps in the persistent AF group were significantly greater than those in the non-persistent AF group (25.8？±？5.0？dB vs. 17.4？±？10.2？dB, p？=？0.047), whereas there was no significant difference in LA diameter between the persistent AF and the non-persistent AF group. There was significant difference in persistent AF-free survival after the baseline measurements in the subjects stratified by IBS value (<20？dB versus ≥20？dB) (univariate Cox regression analysis: hazard ratio: 8.74, p =0.046).Using IBS values measured by TEE, we can identify an increase in atrial degeneration that may predict the occurrence of persistent AF before LA dilation.Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and is associated with increased mortality and morbidity [1,2]. Left atrial (LA) structural, functional and pathological remodeling occurs in response to conditions such as tachycardia, volume and/or pressure overload, diastolic dysfunction, ischemia and valvular disease [3]. Risk stratification for the development of AF based on LA remodeling may have a major public health impact. Parameters that reflect LA size such as LA dimension (LAD) and LA volume (LAV) are markers of elevated left ventricular filling pressure and have been proposed as predictors of AF [4-6]. However, there have been few studies that examined whether LA pathological degeneration predicts the risk of AF, because assessment of LA function has been limited by the lack of appropriate methods. An