Hemodynamic findings in severe tricuspid regurgitation.

Tricuspid regurgitation (TR) most commonly occurs in response to right ventricular (RV) dilation with structural abnormalities in the tricuspid valve being rarer. In addition to RV size and valvular integrity, the amount of TR is influenced by RV preload and afterload, the respiratory cycle, left heart function and atrial fibrillation. Hemodynamic changes in right atrial (RA) pressures in severe TR include elevated mean pressures, a large systolic wave called an "s" wave, a prominent 'Y' descent and a blunted 'X' descent. In addition, RV end diastolic pressure is elevated and cardiac output is reduced, especially with exercise. "Ventricularization" of the RA pressure tracing, in which the contour of the RA pressure is similar to, but of lower amplitude than, the contour of the RV pressure is the most specific finding but is found in a minority of patients with severe TR. In summary, alterations in the RA pressure tracing are common in patients with severe TR but specific hemodynamic findings lack sensitivity, which may in part be due to the large effects of RV preload, RV afterload and RA compliance on the amount of TR.