A person with an aortic valve that is diseased leading to its non-functioning,  is an ideal candidate for a heart valve replacement. The necessity of a heart valve replacement is determined by the ability of the valve to open or close completely. The primary function of the heat valves is to regulate the flow of blood in the right direction facilitated by the opening and closing of the valves.If the valves do not open up properly, then sufficient amount of blood as required by the body is not pumped out of the body causing a strain of the heart. Similarly, if the valves do not close properly, then the blood may tend to leak backwards which again is an obstruction to the flow of blood. Another decisive factor for the need of a heart valve replacement is if the dysfunctionality hinders the normal or day-to-day activities of the person such as breathing, physical exercise etc.