CAGED-BALL prostheses have been widely employed to replace diseased mitral and tricuspid valves, and information concerning the relations of pressure and flow through such prostheses has gradually become available. In both man and experimental animals, however, previous hemodynamic evaluations have of necessity been limited to measurements of right or left atrial and ventricular pressures, heart rate, and mean blood flow. Instantaneous flow patterns through prosthetic valves have been recorded with prostheses mounted in pulse duplicators, but in any such model, the observed patterns of flow can at best be only gross approximations of those which obtain in life. Thus, such important factors as the presence or absence of atrial contraction, changes in velocity of ventricular contraction, and abnormalities of cardiac rhythm and conduction cannot be reproduced accurately.
In the present study, the instantaneous relations of pressure and flow across a ball-valve prosthesis in the tricuspid position were assessed in calves.