What Are The Causes And Risk Factors Of Tricuspid Valve Regurgitation?

Tricuspid valve regurgitation is a heart disorder where blood flows backward into the right atrium from the right ventricle. This backflow occurs because the tricuspid valve between the right atrium and ventricle does not close tight enough. The regurgitation occurs as the left ventricle contracts to pump blood to the lungs. Healthy valves in the heart open up just enough for blood to flow through them, and then they quickly close tightly so blood doesn't move backward.

A mild case of tricuspid valve regurgitation may not manifest with any symptoms, but moderate to severe cases can manifest with symptoms of fatigue, swelling, weakness, neck vein pulsing, and reduced urine output. Diagnosis is made using a Doppler echocardiogram and or cardiac catheterization. The severity of a patient's tricuspid valve regurgitation and the underlying cause of the disorder will determine the method used to treat it.

Carcinoid Syndrome

Carcinoid syndrome is a complication of a rare kind of tumor called a carcinoid tumor. This condition occurs when the patient's carcinoid tumor releases certain chemicals in the body that have adverse effects on various organs throughout the body. These tumors usually develop in a patient's lungs or within their gastrointestinal tract. Most often, carcinoid syndrome occurs in individuals who already have a metastasized advanced-stage carcinoid tumor. The substances of which the carcinoid tumor may secrete include histamine, prostaglandins, 5-hydroxytryptamine, and tachykinins. 

These substances are known to cause a reaction in the tissues of the heart where endocardial plaques and dense fibrous tissue build up on the parts of the heart valves. Not only are the leaflets of the valves affected, but also the papillary muscles and the tendinous chord parts of the heart valves. The plaques cause the tricuspid valve to become distorted or abnormally shaped, which results in functional impairment of the valve. The impairment causes the regurgitation of blood through the tricuspid valve.

Endomyocardial Biopsy

An individual who undergoes an endomyocardial biopsy is at an increased risk of having tricuspid valve regurgitation. An endomyocardial biopsy is a rather invasive procedure used as a diagnostic tool in individuals with some cardiovascular diseases or to collect small samples of heart muscle tissue for analyzation. It is most often performed in patients who need monitoring for organ rejection after undergoing a heart transplant. The complication of tricuspid valve regurgitation is relatively common in individuals who have undergone this procedure. 

This complication can be explained by the inability of visual assistance tools like fluoroscopic guidance and two-dimensional transthoracic echocardiography to provide the operating surgeon with a sufficient visualization of the tricuspid valve chordae and tendineae attachments. This complication even occurs in individuals who are operated on by highly experienced and specialized surgeons, because contact with the tricuspid valve apparatus during this procedure is nearly impossible.

Ebstein's Anomaly

Ebstein's anomaly is an uncommon congenital heart defect where abnormalities are present in certain parts of the tricuspid valve of an individual's heart. Individuals affected by Ebstein's anomaly have a tricuspid valve in their heart muscle that separates the right atrium and the right ventricle at a lower position than it does in individuals who do not have this defect. The three leaflets that make up the tricuspid valve in patients with this defect are often considerably larger than they are in a healthy individual. 

The tricuspid valve often functions poorly because of how these two combined abnormalities affect the normal flow of blood through the individual's heart. A poorly functioning tricuspid valve allows the blood in the heart to flow backward into the right atrium instead of forward into the pulmonary artery. When this defect is left untreated, a severe case of tricuspid valve regurgitation will develop, and the patient will experience heart failure from an enlarged heart. Ebstein's anomaly is the most prevalent congenital heart disease that causes tricuspid valve regurgitation.

Congenital Heart Disease

Congenital heart disease is a group of birth defects related to the structure of a patient's heart. Congenital heart disease can involve the veins and arteries near the heart, the valves of the heart, and or the walls of the heart. Most individuals with congenital heart disease will have more than one defect present in their heart. An individual may be born with irregularly shaped tricuspid heart leaflets that allow the valve to leak blood in the wrong direction. 

Their tricuspid valve may be located in the wrong position or at the wrong angle between the right atrium and right ventricle. The tricuspid valve may even be absent altogether in some patients. In addition, an individual could be born without enough tendons or too many tendons that attach the tricuspid valve to the heart muscle. Furthermore, any congenital heart defects that put abnormally high pressure on the right ventricle can cause the tricuspid valve to become damaged or weakened, allowing for the regurgitation of blood..

Marfan Syndrome

Marfan syndrome is a genetic disorder that involves the connective tissue or the tissue that supports and anchors the organs, cells, and other types of tissue within the body. This disorder is progressive or gets worse with aging. Marfan syndrome is caused by a gene mutation that results in absent or abnormal production of a protein responsible for the elasticity and strength of the body's connective tissues. Marfan syndrome most commonly affects the skeleton, eyes, blood vessels, and heart. The most prominent manifestation of this disorder is the faulty connective tissue that causes any affected organ components to become weak and impaired as well. 

Marfan syndrome can have detrimental effects on the heart and large arteries. The tissue that makes up the aorta can be very fragile and may result in an aortic tear or rupture. The tissue that makes up the valves of the heart can be weaker and thinner than normal in individuals affected by Marfan syndrome. This weakness causes the valve tissues to stretch out abnormally and function incorrectly. The leaflets of the tricuspid valve often resemble thin floppy membranes instead of firmly anchored, healthy valve segments. This weakness of the valve results in the inappropriate backflow of blood.