aortic valve

Examples of aortic valve in the following topics:

• Operation of Semilunar Valves

  • The aortic valve separates the left ventricle from the aorta and has three cusps .
  • When ventricular systole ends, pressure in the left ventricle drops rapidly, and the aortic pressure forces the aortic valve to close.
  • Similar to the aortic valve, the pulmonary valve opens in ventricular systole, when the pressure in the right ventricle exceeds the pressure in the pulmonary artery.
  • This anterior view of the heart indicates the semilunar valves, the aortic and pulmonary valves.
  • Describe the operation of the semilunar valves, the aortic and pulmonary valves

• Heart Valve Disorders

  • Valvular heart disease is any disease process involving one or more of the valves of the heart (the aortic and mitral valves on the left and the pulmonary and tricuspid valves on the right).
  • Valvular heart disease includes aortic and mitral valve disorders, and pulmonary and tricuspid valve disorders.
  • Both tricuspid and pulmonary valve diseases are less common than aortic or mitral valve diseases due to the lower pressure those valves experience.
  • The center of the image shows an aortic valve with severe stenosis due to rheumatic heart disease.
  • The aorta has been removed to show the thickened, fused aortic valve leaflets.

• Heart Sounds

  • The two major heart sounds are 'lub' (from the closure of AV-valves) and 'dub' (from the closure of aortic and pulmonary valves).
  • It is caused by the closure of the semilunar (aortic and pulmonary) valves following ventricular systole.
  • S2 is split because aortic valve closure occurs before pulmonary valve closure.
  • During inspiration (breathing in) there is slightly increased blood return to the right side of the heart, which causes the pulmonary valve to stay open slightly longer than the aortic valve.
  • Due to this, the naming convention is to divide the second sound into two second sounds, A2 (aortic), and P2 (pulmonary).

• Fibrous Skeleton of the Heart

  • The aortic ring: encircles the aortic valve.
  • It provides support for the aortic valve so that it is open, yet does not have backflow.
  • The pulmonary ring: encircles the pulmonary valve.
  • Similarly to the aortic ring, the pulmonary ring provides structural support for the pulmonary valve.
  • The left fibrous ring: encircles the bicuspid valve.

• Systemic and Pulmonary Circulation

  • The blood is then pumped through the tricuspid valve into the right ventricle.
  • Once entering the left heart, the blood flows through the bicuspid valve into the left ventricle.
  • From the left ventricle, the blood is pumped through the aortic valve into the aorta to travel through systemic circulation, delivering oxygenated blood to the body before returning again to the pulmonary circulation.
  • The blood is then pumped through the mitral valve into the left ventricle.
  • From the left ventricle, blood is pumped through the aortic valve and into the aorta, the body's largest artery.

• Ascending Aorta

  • The ascending aorta is the first portion of the aorta; it includes the aortic sinuses, the bulb of the aorta, and the sinotubular junction.
  • The aortic root is the portion of the ascending aorta beginning at the aortic annulus, the fibrous attachment between the heart and the aorta, and extending to the sinotubular junction.
  • Just above the aortic valve are three small dilatations called the aortic sinuses, the two anterior sinuses give rise to the coronary arteries, the third posterior sinus does not usually give rise to any vessels and so is known as the non-coronary sinus.
  • The sinotubular junction is the point in the ascending aorta where the aortic sinuses end and the aorta becomes a tubular structure.
  • At the junction of the ascending aorta with the aortic arch, the caliber of the vessel is increased, owing to a bulging of its right wall.

• Heart Murmurs

  • Heart murmurs are pathologic heart sounds indicative of valve and blood flow abnormalities.
  • Yet most heart problems do not produce any murmur and most valve problems also do not produce an audible murmur.
  • Anatomical sources of heart murmurs include stenosis of the bicuspid aortic valve which tends to appear between 40 and 70 years of age, and stenosis of the tricuspid aortic valve where symptoms more likely to appear after 80 years of age.
  • The first heart sound is caused by the atrioventricular valves--Mitral (M) and Tricuspid (T)--and the second heart sound is caused by the semilunar valves--Aortic (A) and Pulmonary/Pulmonic (P).
  • Heart murmurs are often the result of leaky valves.

• Great Vessels of the Heart

  • The venae cavae are not separated from the right atrium by valves.
  • Blood is pumped from the left ventricle through the aortic valve, into the aorta.
  • When the left ventricle contracts to force blood through the aortic valve into the aorta, the aorta expands.
  • It breaks off into the aortic sinuses, some of which form the coronary arteries.
  • Blood first passes through the pulmonary valve as it is ejected into the pulmonary arteries.

• Blood Supply to the Lungs

  • The vena cava fills the right atrium with blood, which then ejects blood into the right ventricle by passing through the tricuspid valve.
  • After blood fills in the right ventricle, it contracts and pumps the blood through the pulmonary valve, and into the pulmonary arteries.
  • This blood then enters and fills inside the left atrium, which pumps it through the mitral valve (also called bicuspid) into the left ventricle.
  • The blood fills inside the left ventricle and is then pumped through the aortic valve into the aorta, which marks the beginning of systemic circulation.

• Marfan Syndrome

  • The most serious complications are defects of the heart valves and aorta.
  • The most serious symptom of Marfan's is a dilated aorta or an aortic aneurysm.
  • Sometimes, no heart problems are apparent until the weakening of the connective tissue in the ascending aorta causes an aortic aneurysm or aortic dissection; a surgical emergency.
  • The goal of treatment is to slow the progression of aortic dilation and damage to heart valves by eliminating arrhythmias, minimizing the heart rate, and minimizing blood pressure.
  • If the dilation of the aorta progresses to a significant diameter aneurysm, causes a dissection or a rupture, or leads to failure of the aortic or other valve, then surgery becomes necessary.