The tricuspid valve, or right atrioventricular valve, is on the right dorsal side of the mammalian

heart The heart is a muscular Organ (biology), organ found in humans and other animals. This organ pumps blood through the blood vessels. The heart and blood vessels together make the circulatory system. The pumped blood carries oxygen and nutrie ...

, at the superior portion of the

right ventricle A ventricle is one of two large chambers located toward the bottom of the heart that collect and expel blood towards the peripheral beds within the body and lungs. The blood pumped by a ventricle is supplied by an atrium (heart), atrium, an adjace ...

. The function of the valve is to allow

blood Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood is com ...

to flow from the

right atrium The atrium (; : atria) is one of the two upper chambers in the heart that receives blood from the circulatory system. The blood in the atria is pumped into the heart ventricles through the atrioventricular mitral and tricuspid heart valves. ...

to the right ventricle during

diastole Diastole ( ) is the relaxed phase of the cardiac cycle when the chambers of the heart are refilling with blood. The contrasting phase is systole when the heart chambers are contracting. Atrial diastole is the relaxing of the atria, and ventricul ...

, and to close to prevent backflow ( regurgitation) from the right ventricle into the

during right ventricular contraction (

systole Systole ( ) is the part of the cardiac cycle during which some chambers of the heart contract after refilling with blood. Its contrasting phase is diastole, the relaxed phase of the cardiac cycle when the chambers of the heart are refilling ...

Structure

The tricuspid valve usually has three cusps or leaflets, named the anterior, posterior, and septal cusps. Each leaflet is connected via

chordae tendineae The chordae tendineae (: chorda tendinea) or tendinous cords, colloquially known as the heart strings, are inelastic cords of fibrous connective tissue that connect the papillary muscles to the tricuspid valve and the mitral valve in the heart. ...

to the anterior, posterior, and septal

papillary muscle The papillary muscles are muscles located in the ventricles of the heart. They attach to the cusps of the atrioventricular valves (also known as the mitral and tricuspid valves) via the chordae tendineae and contract to prevent inversion or ...

s of the

, respectively. Tricuspid valves may also occur with two or four leaflets; the number may change over a lifetime.

Function

The tricuspid valve functions as a one-way valve that closes during ventricular systole to prevent regurgitation of blood from the right ventricle back into the right atrium. It opens during ventricular diastole, allowing blood to flow from the right atrium into the right ventricle. The back flow of blood is also known as regression or

tricuspid regurgitation Tricuspid regurgitation (TR), also called tricuspid insufficiency, is a type of valvular heart disease in which the tricuspid valve of the heart, located between the right atrium and right ventricle, does not close completely when the right ventr ...

. Tricuspid regurgitation can result in increased ventricular preload because the blood refluxed back into the atrium is added to the volume of blood that must be pumped back into the ventricle during the next cycle of ventricular

. Increased right ventricular preload over a prolonged period of time may lead to right ventricular enlargement (dilatation), which can progress to right heart failure if left uncorrected.

Clinical significance

Infected valves can result in

endocarditis Endocarditis is an inflammation of the inner layer of the heart, the endocardium. It usually involves the heart valves. Other structures that may be involved include the interventricular septum, the chordae tendineae, the mural endocardium, o ...

intravenous drug Drug injection is a method of introducing a drug into the bloodstream via a hollow hypodermic needle, which is pierced through the skin into the body (usually intravenously, but also at an intramuscular or subcutaneous, location). Intravenous ...

users. Patients who inject narcotics or other drugs intravenously may introduce infection, which can travel to the right side of the heart, most often caused by the

bacteria Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micr ...

'' S. aureus''. In patients without a history of intravenous exposure, endocarditis is more frequently left-sided. The tricuspid valve can be affected by

rheumatic fever Rheumatic fever (RF) is an inflammation#Disorders, inflammatory disease that can involve the heart, joints, skin, and brain. The disease typically develops two to four weeks after a Streptococcal pharyngitis, streptococcal throat infection. Si ...

, which can cause

tricuspid stenosis Tricuspid valve stenosis is a valvular heart disease that narrows the opening of the heart's tricuspid valve. It is a relatively rare condition that causes stenosis (increased restriction of blood flow through the valve). Cause Causes of tricuspi ...

or tricuspid regurgitation. Some individuals are born with

congenital A birth defect is an abnormal condition that is present at childbirth, birth, regardless of its cause. Birth defects may result in disability, disabilities that may be physical disability, physical, intellectual disability, intellectual, or dev ...

abnormalities of the tricuspid valve. Congenital apical displacement of the tricuspid valve is called

Ebstein's anomaly Ebstein's anomaly is a congenital heart defect in which the septal and posterior leaflets of the tricuspid valve are displaced downwards towards the apex of the right ventricle of the heart. Ebstein's anomaly has great anatomical heterogeneity tha ...

and typically causes significant

. Certain carcinoid syndromes can affect the tricuspid valve by producing fibrosis due to

serotonin Serotonin (), also known as 5-hydroxytryptamine (5-HT), is a monoamine neurotransmitter with a wide range of functions in both the central nervous system (CNS) and also peripheral tissues. It is involved in mood, cognition, reward, learning, ...

production by those tumors. The first endovascular tricuspid valve implant was performed by surgeons at the

Cleveland Clinic Cleveland Clinic is an American Nonprofit organization, nonprofit Academic health science center, academic Medical centers in the United States, medical center based in Cleveland, Ohio. Owned and operated by the Cleveland Clinic Foundation, an O ...

Tricuspid regurgitation

Tricuspid regurgitation Tricuspid regurgitation (TR), also called tricuspid insufficiency, is a type of valvular heart disease in which the tricuspid valve of the heart, located between the right atrium and right ventricle, does not close completely when the right ventr ...

is common and is estimated to occur in 65–85% of the population. In the

Framingham Heart Study The Framingham Heart Study is a long-term, ongoing cardiovascular cohort study of residents of the city of Framingham, Massachusetts. The study began in 1948 with 5,209 adult subjects from Framingham, and is now on its third generation of partic ...

presence of any severity of tricuspid regurgitation, ranging from trace to above moderate was in 82% of men and in 85.7% of women. Mild tricuspid regurgitation tends to be common, benign, and in structurally normal tricuspid valve apparatus can be considered a normal variant. Moderate or severe

is usually associated with tricuspid valve leaflet abnormalities and/or possibly annular dilation and is usually pathologic which can lead to irreversible damage of

cardiac muscle Cardiac muscle (also called heart muscle or myocardium) is one of three types of vertebrate muscle tissues, the others being skeletal muscle and smooth muscle. It is an involuntary, striated muscle that constitutes the main tissue of the wall o ...

and worse outcomes due to chronic prolonged

right ventricular volume overload Volume overload refers to the state of one of the Heart#Structure, chambers of the heart in which too large a volume of blood exists within it for it to function efficiently. Ventricle (heart), Ventricular volume overload is approximately equival ...

Additional images

File:Slide14bek.JPG, Tricuspid valve. Deep dissection. File:Tricuspid valve * Válvula tricúspide.svg, Tricuspid valve marked in yellow. File:MitralInsufficiency.jpg, Diagram of tricuspid insufficiency/regurgitation. Marked in black arrow.

References

External links

* * Photo of model
circulation/tricuspidvalve04
at

Waynesburg College Waynesburg University is a private Christian university in Waynesburg, Pennsylvania, United States. It was established in 1850 and offers undergraduate and graduate programs in more than 70 academic concentrations. The university enrolls aroun ...

Cardiac Valve Animations - Perioperative Interactive Education Group
{{DEFAULTSORT:Tricuspid Valve Cardiac anatomy Heart valves