Introduction: The tricuspid valve is an atrioventricular valve located on the right side of the heart, which consists of the fibrous tricuspid annulus (TA), three valvular leaflets and a supporting apparatus, the papillary muscles and the tendinous chords. The TA is an oval-shaped three-dimensional (3D) fibrous structure with a complex spatial movement during the cardiac cycle. Three-dimensional echocardiography (3DE) could help during "en-face" assessment of TA dimensions and related functional properties featuring its "sphincter-like" function. TA plane systolic excursion (TAPSE) is a displacement of the lateral edge of the TA toward the apex in systole measured in apical long-axis using M-mode echocardiography (MME). The aim of this study was to determine potential relationships between TA size and its "sphincter-like" and "longitudinal" functions in healthy adults with no functional tricuspid regurgitation.
Methods: The present study consisted of 119 healthy patients (age: 34.6 ± 11.5 years, 70 men) who underwent routine echocardiography with M-mode-derived TAPSE measurement and 3DE. Two subgroups of healthy subjects were compared with each other. A total of 29 subjects with TAPSE between 17 and 21 mm were compared with 90 cases with TAPSE ≥ 22 mm.
Results: Subjects with TAPSE of 17-21 mm had tendentiously dilated TA dimensions compared with subjects with TAPSE ≥ 22 mm. Significant differences could be detected in the end-systolic TA area (5.85 ± 1.90 cm2 vs. 3.70 ± 1.22 cm2, p < 0.05), leading to impaired TAFAC (24.8 ± 9.0% vs. 35.1 ± 9.1%, p < 0.05) in subjects with lower TAPSE (17-21 mm) compared with subjects with TAPSE ≥ 22 mm. TAPSE did not show correlations with any TA size or "sphincter-like" functional parameters as determined using 3DE.
Conclusions: Three-dimensional echocardiography is capable of measuring TA dimensions and functional "sphincter-like" properties, which are associated with MME-derived TAPSE, suggesting a sensitive and harmonic TA function in healthy adults without functional tricuspid regurgitation.
Keywords: echocardiography; healthy; speckle tracking; three-dimensional; tricuspid annulus.