Assessment of tricuspid valve annulus size, shape and function using real-time three-dimensional echocardiography

Tricuspid annulus (TA) evaluation continues to be a major problem in the surgical decision-making process. Obviously, 2-dimensional transthoracic echocardiography (2D TTE) is limited in TA visualization due to its complex 3D shape. The study aimed to determine TA morphology, size and function with real-time three-dimensional echocardiography (RT3DE) in 40 patients divided into two equal groups (I: normal TA and II: dilated). 2D TTE measurements included TA diameter (TAD) at apical 4-chamber (AP4CH) and parasternal short axis (PSAX) views. RT3DE measurements included TA area (TAA), major TAD and minor TAD. TA fractional shortening (TAFS), and TA fractional area change (TAFAC) were calculated from end-systolic and end-diastolic measurements. RT3DE allowed visualization and measurement of the entire oval-shaped TA in all patients irrespective of its size (normal or dilated). 2D TTE measurement of TAD at both AP4CH and at PSAX views was significantly smaller than the major TAD measured by RT3DE (P<0.0001) and nearly matched with the minor TAD in all patients. Calculation of TAFS was comparable with both techniques. TAFAC was significantly higher than TAFS (P<0.0001). So, RT3DE could be relied on more accurately than 2D TTE in the assessment of TA size and function which may aid in decision-making and selection of proper surgical procedure when indicated.