Pulmonary Valve Stenosis
Pulmonary valve stenosis narrows the valve between the right ventricle and the lung arteries. This may occur due to stiffening or hardening of the valve that results in reduced flow of blood to the heart through the valve. It is a congenital condition affecting the heart. However, it may occur in adults as a complication of other medical ailments.
The stenosis or narrowing may range from mild to severe, with mild form presenting no clinical symptoms and may be diagnosed on a routine check-up. However, moderate to severe forms of pulmonary valve stenosis may present clinical symptoms and require aggressive treatment options. These include valve repair or replacement procedures.
Symptoms
A mild form of pulmonary valve stenosis shows no symptoms. However, moderate and severe forms vary in clinical presentation depending on the extent of the block of blood flow to the heart. Some signs and symptoms of pulmonary valve stenosis are:
Shortness of breath
Murmurs heard with a stethoscope
Rapid heart rate
Chest pain
Lowered exercise tolerance
Fatigue
Dizziness or fainting
Heavy or rapid breathing
Swelling in the feet, ankles, face, eyelids, and abdomen.
Cyanosis or blue discolouration seen on the lips, fingers, and toes
Younger children or infants may appear cyanotic or blue due to the reduced flow of blood in the body.
Causes
Pulmonary valve stenosis is a congenital heart valve disease usually diagnosed at birth or early childhood. However, it can also be diagnosed later in life, resulting from many factors related to heart disease. In addition, pulmonary valve stenosis occurs in 2-3% of people with other congenital heart defects, such as:
Tetralogy of Fallot: It is a condition in which the normal blood flow to the heart is impaired.
Pulmonary atresia: A defect in the pulmonary valve, due to which the valve does not form, prevents blood from flowing to the lungs.
Truncus arteriosus: The arteries are combined instead of being split into two, allowing oxygen-rich blood to blend with oxygen-poor blood.
Aortic valve stenosis
Atrial septal defect
Ventricular septal defect
Transposition of the major vessels
Patent ductus arteriosus
Other causes of pulmonary artery stenosis include:
Rubella syndrome
Williams syndrome,
Alagille syndrome
Takayasu's arteritis
Problems that compress or apply pressure on the child's pulmonary artery from the outside.
Surgical causes of pulmonary artery stenosis
Some people may get pulmonary artery stenosis as a complication of surgery, such as:
Transplant of the lungs
Surgery to fix the congenital heart issue or to enhance the flow of blood through the patient's heart.
Pulmonary artery banding purposely narrows the child's artery to lower blood flow to the lungs.
Diagnosis
Pulmonary valve stenosis, which often occurs as a congenital disability, is diagnosed at birth or in early childhood. A physical exam and the recording of the medical history and symptoms are done to diagnose pulmonary valve stenosis. In addition, doctors use a stethoscope to listen to the patient's heartbeats and look for a whooshing sound or murmur that is caused by turbulent blood flow across the narrowed valve.
Doctors may advise certain tests to confirm pulmonary valve stenosis and evaluate the heart condition in adults and children alike, which include:
Echocardiogram: An echocardiogram can confirm a diagnosis of pulmonary valve stenosis. In addition, it can help determine the severity of the condition. It is a painless test that records the electrical activity of the heart. Patches or electrodes are attached to various spots on the chest, wrist, and ankles. Its wires are connected to a computer that displays results.
Chest X-ray: This shows the condition of the heart and lungs and helps determine if it has enlarged in size or shows any other damage.
Stress test: Some kinds of tachycardia are triggered by exercise or strenuous physical activity. The heart's activity is monitored during a stress test while walking on a treadmill or riding a stationary bicycle.
Catheterisation of the heart: Cardiac catheterisation allows a catheter to be directed through a blood vessel to the heart. This procedure can help diagnose or treat certain heart conditions, such as embolisms or arrhythmias. In addition, cardiac catheterisation provides essential information about the components of the heart, such as heart valves, heart muscles, and blood vessels.
Other tests include:
Computed tomography (CT): The advanced 3D CT technology provides doctors with an accurate evaluation of any morphological changes in the valve.
Magnetic resonance imaging (MRI): In recent years, MRIs have proven to help evaluate valve pathology owing to the ability of MRI to assess the dynamics of the flow.
Event monitoring: When long-term heart functioning readings need recording, event monitoring is advisable.
Holter monitoring: Continuous monitoring of the heart rhythm can be done using this portable device. It can be used for several weeks.
Pulmonary angiography: This test uses X-rays to examine how the blood flows through the valve and requires injecting contrast material into a vein. Healthcare providers use angiography to locate any structural changes in the valve and the extent of narrowing of the valve.
Perfusion scan: This scan involves injecting a small amount of radioactive material to assess how well blood is flowing through each lung.
Treatment
Mild pulmonary valve stenosis requires only regular check-ups if no symptoms occur. However, intervention may be required to repair or replace the valve for moderate and severe pulmonary valve stenosis.
The type of surgery depends on the valve's condition and the patient's overall health. The heart surgery procedures to treat pulmonary valve stenosis are:
Balloon valvuloplasty
Valvuloplasty improves blood flow through the heart and reduces the symptoms of pulmonary valve stenosis. However, the chances of relapse are high, which means that the valve may narrow again. Hence, in the future, some people will require valve repair or replacement.
Pulmonary valve replacement
If balloon valvuloplasty is contraindicated or cannot be performed, open-heart surgery or a catheter procedure may be done in order to replace the pulmonary valve. If other congenital heart defects prevail, those can also be repaired during the surgery.
People who have undergone pulmonary valve replacement need to take prophylactic antibiotics before any invasive or dental procedures. This prevents chances of infection.
Complications
Some of the possible complications of pulmonary stenosis include:
Infective endocarditis: People with heart valve problems like pulmonary valve stenosis carry an increased risk of developing bacterial infections of the heart, affecting its inner lining.
Irregular heartbeat or arrhythmia: Irregular heartbeats may pose a threat if the valve prolapses, leading to severe regurgitation, followed by swelling of the heart chamber.
Thickening of the heart muscle: The increased strain on the heart causes the heart walls to thicken, leading to right ventricular hypertrophy.
Heart failure: If the right ventricle pumps inadequate blood, the heart eventually fails to function. Some of its symptoms include shortness of breath and swelling of the legs and abdomen.
Pregnancy complications: The risks of complications during parturition and delivery are increased for women with severe pulmonary valve stenosis.
Risk Factors
Many conditions or factors contribute to causing pulmonary valve stenosis. Some of these include:
Rheumatic fever: It is a complication of strep throat that can cause permanent damage to the heart and its valves. Furthermore, it can increase the risk of developing pulmonary valve stenosis later in life.
Noonan syndrome: It is a genetic disorder that damages the heart and its valves and is one of the causes of pulmonary valve stenosis.
Carcinoid syndrome: Carcinoid syndrome is a rare cancerous tumour that releases chemicals into the bloodstream that cause shortness of breath, flushing, and other symptoms. Furthermore, it may damage the valves of the heart when the syndrome spreads and involves the heart.
German measles (rubella): Having rubella during pregnancy adds to the risk of developing pulmonary valve stenosis in the baby since it can be vertically transmitted.
History of radiation therapy to the chest
Prognosis
The prognosis of treating pulmonary stenosis is good. With the advancement in technology, it is possible to prolong a person's life depending on the patient's condition. However, the prognosis is compromised in patients with multiple medical conditions and pulmonary valve stenosis.
Review
Reviewed by Dr. Mily Ray, Consultant - Paediatrics Cardiology, Paediatric (Ped) Cardiology.
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