What are Heart Valves?
The heart contains four valves that help ensure blood flows in one direction through the heart and into the arteries. The four valves are the mitral valve, tricuspid valve, aortic valve and pulmonary valve. Heart valves have flaps called leaflets or cusps that open and close with each heartbeat to let blood pass through the heart and keep it flowing in the proper direction.
What is Heart Valve Disease?
Heart valve disease occurs when one or more of the heart’s valves no longer function properly. There are two main types of valve disease – stenosis and regurgitation. Stenosis occurs when a valve does not open fully, obstructing blood flow. Regurgitation, also called insufficiency, occurs when a valve does not close properly and allows blood to leak backwards. Valve disease can be congenital (present from birth) or acquired later in life due to causes like rheumatic fever, calcification or age-related degeneration of the valve tissue. Untreated, heart valve disease can lead to heart failure or other serious cardiovascular complications.
When are Prosthetic Heart Valves Needed?
Prosthetic or mechanical heart valves are often required to replace a diseased heart valve that no longer functions properly. A prosthetic valve is indicated in the following situations:
– Severe stenosis or regurgitation that causes symptoms like chest pain, fatigue, irregular heartbeat, fainting spells or heart failure despite medical treatment. Surgical repair or replacement is needed.
– Infective endocarditis, where bacteria have infected a heart valve, often requiring valve replacement to treat the infection effectively.
– Rheumatic heart disease that has caused extensive damage to multiple valves necessitating replacement.
– Congenital heart defects present from birth where one or more valves do not form properly and need replacement later in life.
Types of PHV
There are two main types of PHVs – mechanical valves and bioprosthetic or tissue valves.
– Mechanical valves are made of metal materials like titanium and carbon and have moving parts that open and close. Examples are bileaflet valves, tilting disc valves. They last longer but require long-term blood thinning medication.
– Bioprosthetic or tissue valves are made from animal tissue like cow or pig pericardium or valves. They do not require blood thinners but their durability is less and they may need replacement after 10-20 years. Examples are porcine or tissue valves.
Within these groups, valves differ in design, size and technology used which allows surgeons to select the best replacement option based on the patient’s age, lifestyle, risk factors and preferences. Some newer valve designs aim to combine benefits of both groups.
Prosthetic Valve Surgery and Recovery
Replacing a diseased valve with a prosthetic one is generally done through open-heart surgery where the chest is opened and the patient is placed on a heart-lung bypass machine. The procedure takes 2-4 hours.
After surgery, patients are monitored closely in the intensive care unit for a few days. Pain medications and sometimes a temporary pacemaker may be required. Activity levels are gradually increased over 6-8 weeks and follow up visits help monitor valve function and any new medications needed like blood thinners. Lifelong cardiac monitoring and periodic medical checkups are required based on valve type. With rehabilitation, most people can return to normal daily routines within a few months.
Prognosis and Life Expectancy with Prosthetic Valves
Prosthetic heart valve replacement improves quality and length of life for patients with severe valve disease. When cared for properly as directed by the healthcare team, newer valve designs can last 15-20 years or even longer. However, complications can occur like valve thrombosis, bleeding from anticoagulant medication, endocarditis or structural valve deterioration requiring reoperation.
With regular medical follow up and management of associated risks, patients implanted with prosthetic valves can return to a good functional status and an active lifestyle. Prognosis depends on several factors including age, overall health status and access to healthcare services. While a heart transplant may be needed for some, prosthetic valves provide an excellent treatment option with survival rates of over 90% at 10 years Post surgery.
In summary, prosthetic heart valves play an invaluable role in restoring valve function and extending lives of patients with heart valve disease. Ongoing advancements aim to design safer, long-lasting valve replacements with improved patient outcomes. Following medical guidelines is key to maximizing prosthetic valve durability and preventing serious health issues.