The function of the heart's valves is to prevent blood flowing backwards. Pulmonary valve stenosis is a condition affecting one of the heart's four valves: the pulmonary valve. This article describes how the heart valve works and the symptoms and treatments associated with this condition.
Incidence of Heart Valve Disease
The function of the human heart is to pump oxygenated blood around the body and return deoxygenated blood to the lungs where carbon dioxide can be removed from the blood and exhaled; fresh oxygen inhaled and bound to the blood for transportation around the body, starting the process afresh. It is estimated that some 5 million American adults have heart valve disease, mainly due to age. This article will consider the condition of pulmonary valve stenosis, explain what it is and what options exist for treating it.
The Human Heart
The human heart is a muscle which is designed to pump blood around the body, ensuring that cells are supplied with the oxygen and energy that they need and that waste products can be removed from them. Like any pump, the heart needs to be primed (in this case with blood) and the fluid contained until the muscle contracts, expelling it. The human heart consists of four chambers: the left and right ventricles and the left and right atriums. Oxygenated blood enters the heart through the left atrium and is then pumped into the left ventricle. Blood leaves the left ventricle into the aorta; the body’s largest blood vessel, and circulates around the body. Deoxygenated blood enters the right atrium and is pumped into the right ventricle. Blood returns to the lungs via the pulmonary artery.
The Valves and Valve Disorders
In order to prevent back-flow of blood into the four chambers of the heart, each contains a valve. The heart therefore contains four valves: the mitral valve, the aortic valve, the tricuspid valve and the pulmonary valve. Essentially, the valves are simply flaps which close over the exit of the chamber, preventing blood from returning. The mitral valve consists of two flaps whereas the other valves each have three flaps.
The proper functioning of the heart valves may be affected by one (or both) of two conditions: regurgitation or stenosis.
If a patient is suffering from regurgitation, their valve(s) fail to close completely and allow some blood to return to the chamber when it contracts. A patient who is suffering from stenosis of a valve has the problem that the valve has narrowed or does not form properly and this inhibits the flow of blood out of the chamber.
Stenosis of the Pulmonary Valve
The pulmonary valve is located between the right atrium and the right ventricle. The condition of pulmonary valve stenosis is one in which blood flow from the heart to the lungs (deoxygenated blood) is inhibited by a deformity in the pulmonary valve or just above or below the valve itself.
The majority of people who have pulmonary valve stenosis will have had it as a congenital condition, however it can be produced as a complication of another illness or may result from a heart attack. Stenosis of the pulmonary valve can be mild and symptomless, or it may be severe and debilitating. Symptoms can involve a heart murmur, chest pain, fatigue, shortness of breath (particularly during exercise) or fainting.
Mild forms of the condition do not usually progress, but severe cases will require a surgical intervention.
Treatment of Pulmonary Valve Stenosis
The prognosis for somebody requiring treatment of the condition is generally good and the patient is expected to be able to lead a normal life after treatment. Treatment may involve open heart surgery to repair or replace the valve, but in certain cases, it may be treated using the technique of balloon valvuloplasty. In this case, a balloon is inserted into the valve via a vein in the patient’s leg and is then inflated to help more blood to pass through the valve once the balloon has been removed.
- National Heart Blood and Lung Institute, NIH: http://www.nhlbi.nih.gov/health/dci/Diseases/hhw/hhw_anatomy.html
- Stanford Medicine, Anatomy and Functions of the Heart Valves: http://med.stanford.edu/stanfordhospital/healthLib/greystone/heartCenter/heartIllustrations/anatomyandFunctionoftheHeartValves.html
- Pulmonary Valve Stenosis, Mayo Clinic: http://www.mayoclinic.com/health/pulmonary-valve-stenosis/DS00610