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Heart Valves and How They Work

The heart valves play a vital role in the function of the heart

The heart has four heart valves – the aortic, mitral, pulmonary and tricuspid valves. All four valves open and close to help move blood from one area to another. Two of the valves, the mitral and the tricuspid valves, move blood from the upper chambers of the heart (the atria) to the lower chambers of the heart (the ventricles). The other two valves, the aortic and pulmonary valves, move blood to the lungs and the rest of the body through the ventricles. When the heart valves open and close, they create sounds we know as our heartbeat.

Here is an overview of circulation through the heart: First, blood returns from the body to the right atrium. This blood has been depleted of oxygen when the oxygen was delivered to the body tissues, so it is seeking more oxygen to keep the process going. The right atrium, now full of oxygen-depleted blood, pumps the blood through the tricuspid valve into the right ventricle. Then the right ventricle contracts to pump blood through the pulmonary valve into the pulmonary artery. The pulmonary artery brings blood away from the heart to the lungs where the blood receives the oxygen we breathe, becoming oxygen-rich blood.

At the same time the above process is occurring, oxygen-rich blood is returning from the lungs by way of the left atrium. The left atrium then moves the blood through the mitral valve into the left ventricle. When the left ventricle contracts, it moves blood through the aortic valve into the aorta. The aorta then provides blood to the rest of the body.

The job of the valves is to move the blood through the heart. When the two atrium chambers contract, the tricuspid and mitral valves open, which both allow blood to move to the ventricles. When the two ventricle chambers contract, they force the tricuspid and mitral valves to close as the pulmonary and aortic valves open. The blood that is meant to leave the ventricles to travel to the body is supposed to be prevented from flowing in the wrong direction by the parts of the aortic and pulmonary valves called the cusps. The cusps help the valves create a tight seal, which helps blood flow in the correct direction.

Most heart valve disease occurs in the valves on the left side of the heart – the aortic valve and the mitral valve. However, any heart valve can be affected by valve disease.

Valve disorders are categorized by the valve and by the type of dysfunction

Stenosis – When valve openings are narrow or were not formed properly at birth, blood flow can be inhibited. This causes the valve flaps to become stiff, thicken, or fuse together. The heart then must pump harder to help move through the stenotic valves. All valves can experience stenosis.

Regurgitation – When valves do not close all the way, blood can flow backward. This is called regurgitation.

Prolapse – When heart valve leaflets don’t close properly

  • Mitral valve prolapse
  • Pulmonary valve prolapse

Heart valve regurgitation and stenosis can occur together. When blood flow to and from (and in) the heart is affected, the heart can become weak and unable to pump blood effectively. Heart valve disease is one of the main causes of heart failure. It can also lead to dangerous and even deadly arrhythmias.