How Important Are Heart Valves?

how heart valves workMr. Blum, a 78-year-old man with a history of heart disease couldn’t walk very far without feeling short of breath. He scheduled an appointment with his cardiologist. His cardiologist checked his heart function, in particular his aortic valve, which had been replaced before. The cardiologist thought Mr. Blum might be having symptoms indicating his heart may not be functioning properly.

The heart is important because it pumps blood around your body, delivering oxygen and nutrients to your cells and removing waste products. The heart has four chambers: two upper chambers called the right and left atria (singular: atrium) and two lower chambers called the right and left ventricles. There are valves between the atria and ventricles that make sure blood flows in one direction through your heart.

Valves are also located at the “exits” or “doorways” of the heart for this same reason—to make sure blood flows in one direction. The valves located at these points are called the pulmonary and aortic valves. These are one-way valves that prevent blood from flowing through the heart in the reverse direction when the heart is at rest.

Valves in the heart open and close passively, not through muscle contraction. They open when a forward pressure pushes against them and close when a backward pressure pushes against them. The valves are attached to muscles, called papillary muscles, which are attached to the wall of the ventricle and contract when the heart muscle contracts. Although the papillary muscles contract, they do not open or close the valves. Instead, contraction of papillary muscle pulls on the leaflets of the valve during contraction of the ventricle, limiting the movement of the valve, preventing it from bulging into the atria and potentially leaking. The closing of the valves in your heart makes the classic ‘lub’ (AV valve closure) ‘dub’ (aortic/pulmonary valve closure) sound you hear when you use a stethoscope to listen to your heartbeat.

When your valves do not work properly, adequate amounts of blood are not be able to circulate around your body and you may feel very tired. The most common problems with heart valves are either stiffness or leaky. When valves become stiff or narrowed, which is called stenosis, blood cannot freely flow through the valve. Leaky valves result in blood flowing in the opposite direction through your heart, which is called regurgitation.

Indeed, Mr. Blum learned his aortic valve was not functioning properly and was scheduled for a re-operative aortic valve replacement.

Next Steps: