Valvular Disease Valves

The heart contains four heart valves:

  • mitral valve
  • tricuspid valve
  • aortic valve
  • pulmonary valve.

All four heart valves perform the same basic functions: they keep blood moving in the correct direction, rather than leaking backwards.

Heart Valves and Heart Anatomy

The heart is divided into four chambers. Blood enters the heart through the inferior and superior vena cava veins and fills the upper right heart chamber, the right atrium. The tricuspid valve separates the right atrium from the lower right ventricle. When the right atrium is full of blood, the tricuspid valve opens, and blood flows into the right ventricle.

The right ventricle is separated from the pulmonary artery by the pulmonary valve. When the right ventricle is filled, the tricuspid valve closes and the pulmonary valve opens. Blood then moves through the pulmonary valve into the pulmonary artery and heads towards the lungs.

Blood returning from the lungs passes through the pulmonary veins, which empty into the left atrium. The mitral valve separates the left atrium from the left ventricle, and opens when the left atrium is full of blood. Once the left ventricle fills, the mitral valve closes and the aortic valve opens. The aortic valve separates the left ventricle from the aortic artery, which transports blood to the body. Once the left ventricle empties, the aortic valve closes to prevent backflow.

Heart Valve Construction

The heart valves are composed of thin, strong flaps of tissue, also called leaflets or cusps. The aortic valve, pulmonary valve, and tricuspid valve all have three tissue flaps. The mitral valve is unique among heart valves, as it only contains two leaflets.

When the heart valves function properly, blood flows easily through the heart when the valves are open, and cannot flow backwards when the valves are closed.

Damaged or abnormal heart valves interfere with normal blood flow. Birth defects can produce heart valves that either do not close properly or cannot open fully. Infections such as endocarditis (an infection of the heart lining and heart valves), rheumatic fever and aging can all damage heart valves.

Heart Valve Conditions

Defective heart valves that cannot close properly allow some blood to flow back into the emptying heart chamber. This condition is known as valvular regurgitation or valvular incompetency. In other cases, heart valves may not fully open, and less blood can be pumped through the valve. This type of heart valve damage is called valvular stenosis.

Whether heart valves experience stenosis or regurgitation, the immediate result is the same: The heart must work harder to compensate for the impaired blood flow. Over time, this extra stress damages the heart muscles, eventually causing strokes, blood clots and heart failure.

Heart Valves and Their Disorders

Heart Valves Heart Valve Function Related Heart Valve Disorders
mitral valve The mitral valve connects the left atrium to the left ventricle.
  • hypoplastic left heart syndrome
  • mitral regurgitation
  • mitral stenosis
  • primary mitral valve prolapse
  • secondary mitral valve prolapse.
aortic valve The aortic valve connects the left ventricle to the aortic artery.
  • aortic regurgitation
  • aortic stenosis
  • aortic valve calcification
  • bicuspid aortic valve
  • hypoplastic left heart syndrome.
tricuspid valve The tricuspid valve connects the right atrium to the right ventricle.
  • Ebstein’s anomaly
  • tricuspid atresia
  • tricuspid regurgitation
  • tricuspid stenosis.
pulmonary valve The pulmonary valve separates the right ventricle from the pulmonary artery.
  • peripheral pulmonary stenosis
  • pulmonary atresia
  • pulmonary stenosis
  • Tetralogy of Fallot (TOF).