Types of valves
Types of valves
Surgeons can choose from a wide variety of rigid prosthetic heart valves which can be divided into two broad categories
a ) The ball – valve prostheses and
b) The low profile disc valves .
Mitral valve
All prosthetic valves in the mitral position are normally imaged first in the parasternal long axis view . (122) Mitral valve surgery began in the twenteeth century at the pater bent brigham Hospital in 1923 and was developed further after world war II by Harken Etal .
The first successful prosthetic mitral valve replacement was a device implanted by at the national institutes of health in 1959, this was a home made device with artificial chord made of polyurethane . (113)The mitral annulus is an elliptical ring which is composed of dense collagenous tissue surrounded by musle .The circumference of the mitral annulus ranges from 8 to 12 cm during systole , due to annular contraction, the annular circumference (123).
