The Heart, and How it Works

Did you know that your heart is actually a muscle? It’s true. Your heart is just about the size of two fists. This incredible organ is responsible for pumping 5.6 liters of blood from your heart to your feet and back again all in about 20 seconds. Each day, your blood travels about 12,000 miles. To pump the body’s entire supply of blood a very powerful muscle is needed.

Heart function is incredibly complex, yet can be stated quite simply. The heart pumps blood through your entire body. In the lungs, the hemoglobin molecule in your blood grabs onto oxygen. Blood also contains other nutrients necessary for cell function . As the oxygenated blood is pumped out, oxygen is delivered to the body’s cells and organs. The de-oxygenated blood is pushed through the closed circulatory system back to the heart to pick up more oxygen in the lungs. And don’t forget, on the way back to the heart, blood travels through the liver and kidney, where is gets rid of waste and harmful substances. To accomplish this, your heart beats about 100,000 times every day.

The valves control blood flow by a set of flaps. These are sometimes called leaflets or cusps. The heart valves should open and close fully. Sometimes, the heart valves don't work correctly. When valve problems are noticed at birth, they are called congenital heart defects. Valves can become damaged later on by rheumatic fever, infections such as endocarditis, or by damage over time as seen in the elderly. Damaged valves can be leaky if they do not close completely. This is called regurgitation. If the valve is abnormally narrowed, limiting normal flow, it is called stenotic.

A heart attack occurs when the blood supply to the heart muscle is cut off. Portions of the heart are damaged and cannot pump. This can cause a disorganized hearth rhythm, or pumping to stop altogether. Immediate medical care can prevent devastating damage to the heart, so it's vital that you know the warning signs of a heart attack.

If you or someone you are with has any of these symptoms, medical care should be sought immediately.

• Chest discomfort: usually in the center of the chest. It is often described as an unbearable pressure, squeezing, or fullness; “like an elephant is sitting on my chest.” This pain lasts for more than a few minutes, and may come and go.


• Upper body pain: Usually the left arm, but also may include one or both arms, the back, neck, jaw, or stomach. Sometimes described as “tingling”


• Shortness of breath: Usually occurs at the same time as chest pain. May precede chest discomfort.


• Other symptoms: cold sweat, nausea, dizziness or light-headedness.