Tricuspid valve: Tricuspid valve is the valve between the right atrium (upper chamber) and the right ventricle (lower chamber). It prevents backflow of blood from the right ventricle to the right atrium when the latter contracts. Tricuspid valve, as the name implies, has three leaflets. The leaflets are held taut when the right ventricle contracts, by thread like structures attached to the leaflet tips known as ‘chordae tendinae’. These in turn are connected to the sides of right ventricle by small muscles known as ‘papillary muscles’. It is the valve with largest diameter of the four heart valves.
What are the important diseases which can affect the tricuspid valve?
In regions of the world where rheumatic fever is prevalent, rheumatic heart disease is the commonest cause for tricuspid valve disease. But it is seldom involved alone. Mitral valve is usually involved before this valve is involved.
The valve can be infected in main line drug abusers, producing infective endocarditis. Another important disease which can involve the valve is carcinoid syndrome. In this a chemical mediator is secreted by the carcinoid tumour, which travels through the blood and damages the valve.
Can tricuspid valve be involved by birth defects?
The valve can be leaky as a part of birth defects known as endocardial cushion defects. In this condition it is usually associated with defects in the partition between the ventricles (ventricular septal defect) and the atria (atrial septal defect).
Another birth defect of the valve is known as Ebstein’s anomaly. In Ebstein’s anomaly, the valve position is more downwards and the leaflets may be deformed to produce a leaky valve or a partially obstructed valve. It may be associated with an atrial septal defect through which deoxygenated blood from right atrium can mix with the oxygenated blood in the left atrium. This results in bluish discoloration of the body (cyanosis). Ebstein’s anomaly is one cyanotic congenital heart disease (birth defect with bluish discoloration of lips and nails) in which survival to adulthood without surgical treatment is common.
What treatment can be offered to tricuspid valve disease?
Milder varieties do not need any specific treatment. If there is severe leakage of the valve (tricuspid regurgitation), the vale diameter can be reduced using a ring sewed to its base (tricuspid annuloplasty). If the valve is severely damaged, it can be replaced. While replacing, it is better to use a biological valve than a mechanical artificial valve. This is because a mechanical valve has a high risk of clotting in this location as the circulation in the right side of the heart is at low pressure and velocity. Fore the same reason, long term damage to biological valve is lesser and they have a better longevity than on the left side of the heart where the pressures and velocities are higher.
Apart from surgery, many with tricuspid valve disease can be managed with medications.