The tricuspid valve annulus: study of size and motion in normal subjects and in patients with tricuspid regurgitation.

The tricuspid valve leaflets and their annular attachments were recorded by two-dimensional echocardiography from a view of the right ventricular inflow tract obtained by placing the transducer at an intermediate position between the left ventricular apex and the left lower sternal border. The transducer was rotated, and recordings were made at 30 degrees rotational intervals around the circumference of the tricuspid valve annulus. The cyclical pattern of variations in tricuspid annular size was studied with 12 measurements made during the cardiac cycle in five normal subjects. Annular areas and circumferences were measured. The overall motion pattern was similar to that reported in normal mitral valve annular study. Subsequently, in 16 normal subjects and 18 patients with tricuspid regurgitation, the maximum and minimum tricuspid annular sizes and their percent reduction were measured. The mean maximum annular circumference and area were 11.9 +/- 0.9 cm (mean +/- SD) and 11.3 +/- 1.8 cm2 in normal subjects. They were significantly greater in tricuspid regurgitation (14.0 +/- 0.7 cm and 15.8 +/- 1.8 cm2, respectively). The mean minimum annular sizes were much larger in tricuspid regurgitation (12.5 +/- 0.6 cm and 13.0 +/- 1.4 cm2) than in normal subjects (9.6 +/- 0.9 cm, 7.6 +/- 1.4 cm2). Thus, the percent reduction of annular circumference and area were significantly decreased in tricuspid regurgitation. For anatomic correlations, measurements of the tricuspid annular circumference were made at autopsy in 18 hearts without underlying valvular disease. The annular circumference was measured in the fresh and fixed states. The measurement in the fresh state was 13.5 +/- 0.8 cm and in the fixed state was 12.0 +/- 0.8 cm. The values measured in the fixed hearts were more similar to measurements obtained by echocardiography in a group of normal subjects. Thus, tricuspid annular reconstruction by the new two-dimensional echocardiographic method provides additional information about normal and abnormal size and function of the tricuspid valve annulus.