Abstract 16726: Dynamic Analysis of the Tricuspid Annulus -Does Non Planarity of the Annulus Matter?

Abstract

Introduction: Surgical decision-making on the tricuspid valve (TV) hinges on accurate measurements of the tricuspid annulus (TA). 3D echocardiography is more accurate than 2D for dynamic measurement of TA size due to TA non-planarity. Multiplanar reconstruction (MPR) of 3D datasets is easily performed on ultrasound machines but results in inconsistent measurements of minimum and maximum TA size. We developed an alternative method for dynamic TA measurement that accounts for TA non-planarity, to determine if this approach would yield different annulus sizes compared to the MPR method. Methods: 51 normal subjects underwent 3D TTE of the TA (Philips). MPR measurements of the TA were made on a plane passing through 2 pairs of hinge points identified in orthogonal apical views (QLAB, fig.A). The alternative approach used custom software (CS) that initialized TA hinge points in mid-systole (MS) in multiple rotated planes, following the non-planar shape of the TA (fig. B); these were then tracked throughout the cardiac cycle. TA area, antero-posterior and septal-lateral dimensions were measured at end-diastole (ED, TV closure), MS and end-systole (ES, prior to TV opening), and compared between approaches. Results: MPR measurements showed minimum TA size at ED or MS. In contrast, the CS approach resulted in significantly larger measurements and showed minimum TA size at ES (Table). Careful review revealed that in many patients the annular plane in which MPR measurements were made cut through parts of the right atrial (RA) walls. Conclusions: MPR-based TA size may be underestimated because this approach does not account for TA non-planarity, partially identifying RA walls as annular boundary, resulting in a minimum at ED, when the RA is smallest. Alternative software approaches that account for TA non-planarity should be explored with surgical validation and are required to accurately assess TA size and dynamics. This may have implications on TV annuloplasty planning.