Abstract 12030: The Process of Left Atrial Appendage Dysfunction Evaluated by 3D Transesophageal Echocardiography

Abstract

Introduction: Left atrial appendage (LAA) dysfunction progressively evolves in atrial fibrillation (AF) patients. LAA transesophageal echocardiographic (TEE) parameters can predict thrombotic tendencies and AF treatment outcomes. However, the process of LAA dysfunction remains to be elucidated. Methods: Eighty-four persistent AF patients (64men, age 68±10) that underwent TEE were enrolled. We obtained three-dimensional full-volume LAA data from these patients and reconstructed two-dimensional LAA cross sectional images at the orifice and mid-portion level of the LAA. The maximum and minimum cross-sectional LAA areas were measured at each position and the area change ratio at the orifice (ACR-O) and mid-portion (ACR-M) were calculated. We defined low contractility as a decreasing area change ratio (ACR) of <30% at each position and evaluated the associations between the ACR-O, ACR-M, and continuous AF duration. Results: The patients were categorized into three groups based on the ACR-O and ACR-M: those that maintained both ACR-Os and ACR-Ms (n=48, Group 1), those with reduced ACR-Os and maintained ACR-Ms (n=17, Group 2), and those with both reduced ACR-Os and ACR-Ms (n=19, Group 3). There were no patients with maintained ACR-Os and reduced ACR-Ms. The mean continuous AF durations of each group were 29±42, 54±40, and 88±87 months, respectively. In Group 3, the LAA emptying flow velocity was significantly decreased compared to that in Group 1 and Group 2 (38±19, 31±14, 22±11,cm/s) and LAA thrombi were detected more frequently (0%, 12%, 58%). Conclusions: This study suggested that LAA dysfunction occurred from the orifice and progressed toward the mid-portion. When LAA dysfunction extended over the mid-portion, the LAA flow velocity decreased and LAA thrombi were detected more frequently. Even though anticoagulant drugs were administrated in all patients, 58% of patients had thrombi in Group 3. These patients should be considered for additional therapeutic approaches.