Evaluating Prosthetic Heart Valve Hemodynamics By Doppler Echocardiography

Since the first successful unplants of prosthetic heart valves by Starr in 1960, thousands of patients throughout the world have benefited from valvular prostheses. Today, valve replacement is the best and most frequent treatment for critical valve dysfunction in adults. Echocardiography is universally used to confirm normal function or to detect and quantify dysfunction of the valve. Because of shielding it is more difficult to study artificial valves than native valves and the results are harder to interpret because there is no clear-cut distinction between normal and abnormal function: all valves are stenotic compared with normal native valves. In addition artificial valves have different orifice characteristics, downstream flow profiles, and patterns of physiological regargitation: experience gained with one type cannot necessarily be applied to another. In this study we assessed rest, exercise hemodynamics of prosthetic heart valves by Doppler echocardiography, color Doppler flow-convergence method determination of transmitral flow and orifice area, and Doppler echocardiographic assessment of prosthetic valve hemodynamics in an in vitro pulsatile flow model.In order to determine the standard Doppler hemodynamic characteristics of the Medtronic-Hall, St. Jude, Sorin, Jyros, and GK mitral and aortic prosthesis and the value of the continuity equation to calculate the prosthetic valvular area, we performed Doppler echocardiographic study in 324 stable patients(221 miti'al and 103 aortic valve position) with these prosthesis. We measured maximum and mean Doppler Gradients, prosthetic valvular area using the continuity equation. 1. Mitral valve prosthesis: The maximum gradients /mean gradients /Effective areas were 11 mmHg /4 mmHg/2.24 cm~2 (mean). We found no significant differences between the different valves(p>0.05). PHT was 87ms(mean). 2. Aortic valve prosthesis: The maximum gradients /mean gradients /Effective area were 25 mmHg/11mmHg/1.7cm~2 .We found significant differences between St. Jude...