Mayoclinic.org states that heart valves are vital to the proper functioning of the circulatory system as their function is to prevent the blood from regurgitating. Several diseases can destroy or damage valves. When the heart valve's function is severely reduced something has to be done to ensure that blood circulates and is pumped by the heart in the right direction. This usually means either heart valve repair, or complete valve replacement.
Blood Clots
According to Mayoclinic.org, mechanical prosthetic or artificial valves are foreign bodies, with a rough surface, which increase the chance of blood clots being formed over them. This process is known as thrombosis. If a blood clot breaks loose and travels in the patient's blood, it could lodge in the cerebral vessel and cause a stroke, or enter the coronary vessels and cause a heart attack. To reduce the risk of blood clotting, patients with mechanical artificial valves are required to take anticoagulants or medications known as blood-thinners, such as warfarin or Coumadin for the rest of their lives.
Bleeding
According to the Harvard Medical School Patient Education Center, every year approximately 1.3 to 2.7 percent of patients with mechanical valves suffer from a severe bleeding episode. Due to the continuous intake of blood-thinners, patients who receive mechanical heart valve replacements are at a higher risk for these serious life-threatening bleeding episodes. And in order to reduce that risk, mechanical heart replacement patients need close follow-up and monitoring of their bleeding time to ensure that they are not over medicated.
Valve Failure
Valve failure is when a prosthetic valve degenerates and stops functioning causing the patients' original symptoms to reappear. The Harvard Medical School Patient Education Center also notes that tissue valves have the disadvantage of not being as durable as the mechanical valves. They last for a shorter time and may need to be replaced in a revision procedure years down the road. In fact, according to Harvard Medical School Patient Education Center, 50 percent of the patients with biological tissue valves experience valve failure and require replacement within 15 years.
Infection
MayoClinic.com notes that having a prosthetic heart valve is a predisposing factor for infection of the inner lining of the heart---known as endocarditis, because bacteria can readily attach themselves to prosthetic valves and proliferate. These bacteria gain access to the bloodstream through the mouth, the intestines or a skin cut. Patients with prosthetic valves always receive antibiotics for prevention before undergoing any medical, surgical or dental procedure. Infection of prosthetic heart valves usually first presents by fever, chills and shortness of breath. It is a serious condition that is treated via massive intravenous antibiotics. If antibiotics fail, surgical removal of the prosthetic valve may be necessary.
References
- Harvard Medical School Patient Education Center: Heart Valve Replacement
- Mayoclinic.org : Heart Valve Surgery
- New England Journal Of Medicine: Prosthetic Heart Valves
- New England Journal Of Medicine: A Comparison of Outcomes in Men 11 Years after Heart-Valve Replacement with a Mechanical Valve or Bioprosthesis
- MayoClinic.com: Endocarditis
