Arterial valve is a general term occasionally used to describe either of the two valves that control the outflow of blood from the heart’s ventricles into the arterial circulation. These are the aortic valve (between the left ventricle and the aorta) and the pulmonary valve (between the right ventricle and the pulmonary artery). They are more precisely described as semilunar valves, named for the crescent shape of their three cusps.
Both valves open when the ventricles contract during systole, allowing blood to be ejected into the circulation, and close when the ventricles relax during diastole, preventing backflow. Their proper function is essential for maintaining efficient cardiac output. Disease affecting the arterial valves takes two main forms: stenosis (narrowing, which restricts forward flow and increases the work the heart must do) and regurgitation (leaking, which allows blood to flow backwards and reduces the volume of blood reaching the circulation with each beat).
The aortic valve is the most clinically significant for adults, as calcific aortic stenosis becomes increasingly common with age and is a recognised cause of sudden cardiac arrest in severe cases. The pulmonary valve is more commonly affected in congenital heart disease. Both valves can be assessed by echocardiography, and when significantly diseased, can be repaired or replaced surgically or, for the aortic valve, via a transcatheter approach (TAVI).
For more detail, see the individual entries for Aortic Valve and Pulmonary Valve.
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