Heart Valve Replacement

Heart valves are membranous structures separating the four chambers of the heart. Each chamber has a valve in order to facilitate the flow of blood in the right direction. The mitral and tricuspid valve separates the atria and the lower ventricles whereas the aortic valve and the pulmonic valve are situated between the ventricles and the major blood vessels of the heart. The mitral and tricuspid valve have two leaflets and the aortic and pulmonic valve have three leaflets, which along with the annulus play a significant role in maintaining the shape of the heart.

When the valves, especially the aortic valve is not functioning properly, the blood flow through the body is obstructed, causing pressure on the heart to work harder in order to pump blood. This is quite dangerous and can lead to several conditions which can be fatal. It is often accompanied by symptoms like shortness of breath, fatigue, chest pain, loss of consciousness, irregular heartbeat (arrhythmia), heart failure and sudden cardiac death. In order to restore normalcy of the blood flow, tone down the symptoms and preserve the functioning of the heart, there may arise a need for the replacement of the heart valves.

 

A person suffering from heart valve problems need not necessarily show symptoms indicating its presence and may require treatment. The progress of this disease is usually very slow and the symptoms may appear at a later stage. Some of the symptoms associated with this condition are shortness of breath, fatigue, chest pain, loss of consciousness, irregular heartbeat (arrhythmia), heart failure and sudden cardiac death. It is also accompanied by several other symptoms such as dizziness, palpitations,  discomfort in the region of the chest, rapid weight gain and swelling of ankles, feet or abdomen.

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.

A significant number of studies over a period of time has estimated that 89.7% of the treated patients survive for at least two years following the surgery. About 78.4% survive for a period of five years and around 57.0% survive for around ten years. It has also been observed that the five-year survival rate declined by 31.2 % for the patients who are aged above 85 years.

The surgery performed for the replacement of the heart valve is usually considered to be safe. However, every surgical procedure is associated with a minimum number of risk factors or possible complications. Some of them include:

• Bleeding during or after treatment due to damage of blood vessels
• Blood clots leading to heart attack, stroke, or lung problems
• Infection at the incision site
• Infection in the new valve (endocarditis), which is more common with valve replacement
• Pneumonia
• Breathing problems
• Arrhythmias (abnormal heart rhythms)
• Valve failure
• Bad reaction to anaesthetics

It has been observed that when mechanical valves are used for the procedure, they may last for as long as twenty five years and when tissue valves are utilised, they may last for as long as fifteen years. Both these valves have not shown any signs of problems.

A leaky heart valves usually tends to go unnoticed. However, it may sometimes result in death. This entirely depends upon the extent with which it interferes with the normal blood flow of the heart.

A significant number of studies over a period of time has estimated that 89.7% of the treated patients survive for at least two years following the surgery. About 78.4% survive for a period of five years and around 57.0% survive for around ten years. It has also been observed that the five-year survival rate declined by 31.2 % for the patients who are aged above 85 years.

The most common type of heart valve replacement is the aortic valve replacement for aortic stenosis, or the narrowing of the aortic valve. Another common approach is for mitral stenosis, which requires the replacement of the mitral valve. The pulmonary and tricuspid valve replacement are usually not very common and may be recommended by your doctor in extreme cases.

Heart valves are a membranous structure separating the four chambers of the heart. Each chamber has a valve in order to facilitate the flow of blood in the right direction. The mitral and tricuspid valve separates the atria and the lower ventricles whereas the aortic valve and the pulmonic valve are situated between the ventricles and the major blood vessels of the heart. The mitral and tricuspid valve have two leaflets and the aortic and pulmonic valve have three leaflets, which long with the annulus play a significant role in maintaining the shape of the heart.

A valve replacement surgery in India may range in between 2.5 to 2.75 lakhs in the common private hospitals.

A surgical procedure done to replace one or more of the four valves of the heart is called heart valve replacement surgery.

There are four valves in the heart, namely the aortic valve, mitral valve, tricuspid valve, and pulmonary valve. These valves help the blood flow in the right direction through the heart. 
A heart valve replacement surgery is needed when either of the valves of the heart is scarred, fragile, or too damaged to repair.
The valves consist of flaps, called leaflets or cusps. These flaps should ideally open and close once per heartbeat. But when these valves cannot open or close properly, the blood flow through the heart and to the body is interrupted.

The following could be the possible causes of a heart valve disease:

• Congenital condition (present at birth)
• Prolapse (when the heart valves have floppy flaps)
• Increased age
• Presence of holes in the flaps
• Endocarditis (infection of the heart valves)
• Rheumatic fever (a kind of bacterial throat infection)
• Hypertension (high blood pressure)
• Aortic aneurysm (a condition in which there is a dilation of the aorta, which is the main blood vessel of the heart)
• Tumors
• Use of certain types of medications
• Chronic (long-term) inflammatory disorders
• Radiation therapy (a type of cancer treatment using high-speed energy beams to kill the cancer cells)

The following are the symptoms associated with heart valve diseases:

• Shortness of breath
• Chest pain
• Fatigue
• Lightheadedness
• Dizziness
• Retention of fluid, especially in the legs

The different types of valves used for a heart valve replacement surgery are:
1. Mechanical valves: These valves are made up of man-made materials like titanium and carbon. These valves last for a long period of time. A person with a mechanical valve will need to take blood-thinning medications for the rest of his/her life.
2. Biological valves: These valves are made up of human or animal tissue. These valves have a shelf life of approximately 15 to 20 years. Blood-thinning medications are usually not required by a person having this type of valve.

A heart valve replacement surgery is done in the following cases:
1. Regurgitation: When the valves of the heart leak it leads to the valve remaining slightly open, instead of tight closure. This causes the backward flow of blood. This condition is called regurgitation.
2. Stenosis: When the blood vessels become narrow, it leads to a lesser amount of blood flowing to the heart. This condition is called stenosis. The muscles have to work harder in such cases.

The following tests may be performed before a heart valve replacement surgery:
1. Physical examination: The doctor will examine the patient physically. The patient’s symptoms, medical history, and family history are noted.
2. Blood tests and urine tests: These tests help to diagnose any underlying medical condition or infection that may be present.
Imaging tests: Imaging tests like chest x-ray, CT scans, and MRI scans help to obtain images of the heart.
3. Echocardiogram: Sound waves are used in this test to create images of the heart while it is working. This helps the doctor to check the blood flow through the heart and heart valves.
4. Electrocardiogram (ECG or EKG): This test helps to measure the electrical activity of the heart.
5. Stress test: The changes in the heart parameters of a person are noted during some physical activity, or by taking a medication given by the doctor in this test.
6. Cardiac catheterization: A flexible, thin tube, known as a catheter, is inserted through a blood vessel in the arm or groin area, and guided to an artery in the heart. The surgeon injects a dye through the catheter to make the artery more visible on an x-ray. This helps the doctor in obtaining a clear image of the arteries in the heart, and checking how well the heart is functioning. The pressure inside the chambers of the heart can also be measured using this test.

The following preparation may be needed before a heart valve replacement surgery:

• The patient should inform the doctor if he/she had any pre-existing medical conditions.
• If the patient is allergic or sensitive to any medications, anesthetic agents, iodine, latex, or tape, the doctor should be informed about the same.
• If the patient is currently taking any herbs, medications, or supplements, the doctor should be told about the same.
• Quit smoking as soon as possible.
• Inform the doctor if you are pregnant, or are planning to get pregnant.
• The doctor should be informed about any cardiac implanted device, such as a pacemaker, that a patient may be having.
• The patient may be told to stop taking blood-thinners like warfarin and aspirin a few days before the procedure.
• The patient is instructed to not eat or drink anything eight hours before the procedure.

A heart valve replacement surgery can be performed in the one of following ways:
1. Open heart surgery:

• This type of surgery is usually performed under general anesthesia (the patient is put to sleep during the surgery).
• The surgeon makes a long incision or cut, about 6 to 8 inches in length,  in the chest region.
• The surgeon then splits open the breastbone.
• The heart function is now stopped and a heart-lung bypass machine is now attached to the patient to take over the heart function of pumping blood to the rest of the body.
• The damaged valve is removed by the surgeon and replaced by a mechanical or biological valve.
• The heart function is then restarted.
• The chest incision is then closed by the surgeon using sutures (stitches).
• The procedure takes about two to four hours to complete.

2. Minimally invasive procedure:

• In this type of surgery, the surgeon makes small incisions of approximately 2 to 4 inches in the chest area without opening the chest entirely.
• The incisions are made by the surgeon in a J-shaped pattern.
• The damaged heart valve is then removed and replaced by the surgeon.
• This procedure involves less trauma, bleeding, and pain compared to open surgery. The recovery rate is also quicker compared to open surgery.

The post-procedure steps following a heart valve replacement surgery are as follows:

• The patient is usually allowed to go home from the hospital three to ten days after the procedure.
• It is normal to have some bleeding, pain, and swelling following the procedure.
• The doctor prescribes pain killer medications to relieve the pain and discomfort after the surgery.
• Follow-up appointments with your doctor include check-ups and lab tests like x-rays, ECG, and echocardiogram to check the healing.
• If the procedure involves the placement of a mechanical valve, one may need to take blood-thinning medications for the rest of their life. 
• The breastbone takes approximately 6 to 8 weeks to heal.
• Complete recovery may take approximately 3 months.
• The doctor may suggest mild to moderate exercises to help in a rapid recovery.
• Avoid heavy lifting and strenuous physical activities for a few weeks following the procedure.
• If the patient has a desk job, he/she can return to work within 6 to 8 weeks of the procedure. 
• In the case of a job that requires more physical activity, the patient can resume work only three months after the procedure.

The complications associated with a heart valve replacement surgery could include:

• Bleeding
• Infection
• Blood clot formation
• Heart attack
• Stroke (a condition of interrupted blood supply to the brain)
• Arrhythmias (irregular heart rhythms)
• Lung disorders
• Pneumonia
• Dysfunction of the replaced valves
• Death