Comments Surgery:

• Caged-ball valve, historical valve, worse hemodynamics and thrombogenicity than modern mechanical valves
• Available 1961-1965

Comments Echocardiography:

• No EOAi calculator available 

References:

1. Rosenhek et al. Normal Values for Doppler Echocardiographic Assessment of Heart Valve Prostheses. Journal of the American Society of Echocardiography, November 2003
2. Vincent L. Gott el al. Mechanical Heart Valves: 50 Years of Evolution. Ann Thorac Surg 2003; 76:S2230-9