Valvular Stenosis (Blocked or Narrowed Valves)
Valvular stenosis (heart valve narrowing) occurs when one or more heart valves is narrowed, stiffened, thickened or blocked. When this happens, the heart will have to work hard to pump blood across the narrowed valve. If not treated, this may develop into heart failure.
If a person has valvular stenosis, he or she will experience the following signs:
- Shortness of breath with exertion or while lying down
- Chest pain
- Swelling (oedema) of the legs, arms and other parts of the body
- Dizziness and fainting
- Unproductive cough, sometimes with a tinge of blood in the sputum
- Bluish coloration of skin due to absence of oxygen in the body
Types of valvular stenosis (narrowing)
Tricuspid stenosis - Narrowing of the valve between the right atrium and the right ventricle. This is a very rare condition.
If there is narrowing of the tricuspid valve, the right atrium will become enlarged and there will be back pressure on the veins in the body and the liver. This results in swelling of the legs and abdomen, stomach pain, loss of appetite and shortness of breath. Severe cases may require surgery.
- Rheumatic fever (a childhood illness which occurs after an untreated sore throat)
- Birth defects or tumours of the heart (rare)
- Specific drugs especially appetite suppressants
- Carcinoid syndrome
- Shortness of breath
Pulmonary stenosis – Narrowed valve between the right ventricle and the pulmonary artery. This limits blood flow to the lungs and adds pressure to the right ventricle which will lead to heart thickening and eventually enlargement.
- Congenital heart defect
- Easily gets tired during exercise
- Expanded abdomen due to accumulation of fluid (abdominal distension)
- Shortness of breath
- Chest pain
- Bluish of the skin due to absence of oxygen
Mitral stenosis – Narrowed valve between the left atrium and left ventricle. This reduces the flow of blood to the left ventricle causing the left atrium to get enlarged. Enlargement of the left atrium causes abnormal and irregular heart rhythms such as atrial fibrillation. Poor forward flow of blood into the left ventricle results in insufficient blood getting to the body and severe elevation of blood pressure in the lungs that can become life threatening. Medications can be given to treat the symptoms but if the valve narrowing is severe then a procedure will be required to enlarge the valve. Balloon valvuloplasty using a catheter inserted through the groin to stretch the valve is sometimes the first suitable option. Many people with mitral stenosis will eventually need replacement of the mitral valve to relieve the obstruction thereby improving symptoms and life expectancy. In rare cases the valve can be repaired but due to scarring and calcium build-up this is often not feasible.
- Rheumatic fever
- Age related calcification of the mitral valve
- Cardiac tumors (rare)
Aortic stenosis – Narrowed heart valve between the left ventricle and aorta. Among the four valve dysfunction, this is the most common and most dangerous. Once an adult patient developed symptoms of aortic stenosis their life expectancy is reduced to 1-5 years unless the valve is replaced.
- Shortness of breath
- Chest pain, tightness
- Reduced ability to perform normal activities
Diagnosis and Treatment
The primary approach to diagnose a defective heart valve is by listening to the heart for unusual sounds (auscultation) using a stethoscope. You may be asked to change your position or bear down with your abdominal muscles to check if there are changes to the murmur sounds of your heart. Your GP and Cardiologist will perform a physical exam and may order some blood tests. They may then order some of the following tests:
- Transthoracic echocardiography
- Transesophageal echocardiography
- Cardiac catheterization (also called an angiogram)
- Radionuclide scans
- Cardiac magnetic resonance imaging (cMRI)
Depending on the results of the diagnostic tests (which will show the severity level of the disease and its cause), you may either be treated with medication to control or lessen your symptoms. You may also need to undergo open heart surgery to repair or completely replace malfunctioning valves.
People diagnosed with mild valvular stenosis continue to live a normal life and may not require surgery. However, a plan of treatment may still be given such as:
- Protecting the heart from further damage
- Taking medication to manage the symptoms
- Planning for management, self-care and follow-up care
Patients with symptomatic valve narrowing that is usually severe will often require surgery to relieve symptoms and improve life expectancy. For most narrowed heart valves this requires replacement of the heart valve through an operation involving open heart surgery.
How the valvular heart surgery procedure is done?
The procedure is performed in the operating room by a heart surgeon under general anaesthesia with assistance of the heart-lung machine. Tubes for delivery of oxygen and IV fluids are hooked up and the sternum is opened in the midline to expose the heart. The patient is put on the heart-lung bypass machine (also called cardiopulmonary bypass pump) to ensure continuous oxygenated blood flow to all parts of the body except the heart and the heart (coronary) arteries.
Meanwhile, the heart is stopped beating by lowering its temperature and using blood containing a high potassium solution to cause it to stop temporarily. Repair or replacement of the diseased valve(s) is then performed utilizing any of the specific procedures listed under valve repair and valve replacement above.
The heart then resumes beating by restoration of blood flow through the heart arteries at the completion of the valvular surgery.
When the heart is seen to be beating normally again, the heart-lung bypass pump is withdrawn and excess blood around the operation area is suctioned off and chest drainage tubes are placed. Temporary pacing wires are also sometimes attached to the heart and brought out through the chest wall to control the heart rhythm after the operation.
The chest incision is then closed and dressed, and the surgery is completed. The sternum bone is put back together using stainless steel wires that remain in place as the bone heals. They are inert, do not set off metal detectors and are MRI compatible after 6-8 weeks. The remainder of the wound is closed using absorbable (dissolving) sutures.
After heart surgery, the patient is allowed to recover for a few days in the intensive care unit where vital signs are closely monitored. Once awoken and weaned from the ventilator they are moved to the step down unit and then to the post-operative ward. Most often, pain medication, antibiotics and anti-coagulants are given. Mobility is increased each day with the assistance of the physiotherapist and the patient must work on deep breathing and coughing exercises to clear and expand the lungs in order to prevent pneumonia. When the range and duration of movement and physical activity have increased (usually in 5-7 days), the patient is allowed to go home.
Recuperating at home, the patient needs to consider certain things, such as:
- Medications. You may need to continue certain medications for a lifetime (such as the anti-clotting medicine warfarin)
- Wound care
- Exercise and physiotherapy
- Complications to watch out for
- When to go back to work
- Check ups
- Lifestyle modifications
- Cardiac rehabilitation. Cardiac rehabilitation is a clinically supervised program to help heart patients recover and regain their overall physical and mental functioning. This helps to prevent recurrent heart attacks.Cardiac rehabilitation programs include education about cardiac health, lifestyle modifications, psychological support, nutritional advice and much more.
It is best to have a detailed talk with Dr Orr regarding these before going home. So, make sure that all necessary contact numbers are listed down.
Nowadays, the success rate of open heart surgeries, valve repair and replacement included, is very favourable. More so if the disorder or defect is corrected at a stage before severe irreversible complications have set in. Other determining factors for the success of valve repair and replacement are age (the younger the better), previous lifestyle (those who don’t smoke, drink, and have healthy diets tend to fare well), and, of course, the new lifestyle the patient chooses.