What is the tricuspid valve?
The tricuspid valve, at times called the right atrioventricular valve, is the heart valve that divides the right ventricle and the right atrium. It is called the tricuspid valve because it consists of three flaps (aka cusps or leaflets) and it is known as the right atrioventricular valve because of where it lies in relation to the atria and ventricles. The bicuspid valve is also an atrioventricular valve. The tricuspid valve is sometimes also referred to as the “forgotten” or “lost” valve because much more academic focus is placed on the other three cardiac valves.
What does the tricuspid valve look like?
The average size of the tricuspid valve in humans is 5 cm². The three flaps (the septal, posterior and anterior leaflets – called that due to where they are located) of the valve protect its opening—which is bordered by a fibrous ring, the tricuspid annulus—and give the valve a saddle-like shape. Connected to each leaflet is a series of taut, string-like tendons of variable thickness (chordae tendineae) that attach to three papillary muscles in the right ventricle wall. These cords or “heart strings” cause the cusps to join neatly and tightly (coapt) while the valve closes during right ventricular contraction, preventing prolapsing of the valve and blood regurgitation (backflow).
What is the tricuspid valve’s function? How does it work?
The tricuspid valve plays an important role in the heart; it regulates blood flowing between the right atrium (the top right chamber) and ventricle (the bottom right chamber), preventing it from flowing backwards into the atrium. Normally, de-oxygenated blood enters from the inferior vena cava and superior vena cava and accumulates in the right atrium. As it fills up, the three tricuspid flaps are forced open, blood passes through to a relaxed right ventricle and then the right atrium contracts, pushing more blood into the ventricle. Next, the right ventricle contracts, the tricuspid valve closes and blood pushes through the pulmonary valve into the pulmonary artery.
What happens when the tricuspid valve doesn’t function properly?
When the tricuspid valve and/or its structures are defective, damaged or abnormal somehow, it can malfunction, causing a number of symptoms and complications. The deformity may occur due to a congenital defect or a disease, or degeneration that comes with age. Tricuspid regurgitation and tricuspid valve stenosis (less frequently) are two relatively common types of heart valve disease that affect the tricuspid valve, while tricuspid atresia occurs less often. People with valvular disease can be treated successfully, to a large degree. The outcome for patients, however, depends largely on the severity and underlying cause of the problem and one’s personal circumstances.