Children's Hospital Colorado
Heart institute
Heart institute

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About the Healthy Heart

Hearts have a single purpose: to push blood through the lungs so the blood can collect oxygen and to then push that oxygenated blood out to the rest of the body. All of the cells and tissues in the body need oxygen to stay alive.

A blueprint for the heart

Healthy hearts are like a two-story house with walls made of muscles. A healthy heart has four rooms: two small atria stacked on top of two larger ventricles. Doctors refer to the two room stacks (each with one atria and one ventricle) as the left or right side of the heart.

These "rooms" are separated by one-way hallways, called valves, that let blood pass through from one to another, but only in one direction.

How the heart works

Blood without oxygen enters the heart through the chimney of the right atria and fills up the room. Then, with the next heartbeat, blood gets shot downstairs to the right ventricle. That room pumps blood through the pulmonary artery, like a laundry shoot, into the lungs so it can collect oxygen.

When the newly oxygenated blood returns from the lungs, it fills up the left atrium. Then that room dumps it back downstairs to the left ventricle. The left ventricle pumps the oxygen-rich blood out through the aorta, a second laundry shoot, which carries blood to all the small blood vessels in the entire body.

Your heart does this more than 100,000 times a day.

The heart creates your pulse when it contracts its muscles to squirt blood out of your aorta and through all the blood vessels of your body.

When things aren't perfect

Sometimes hearts don't form correctly while a child is developing and growing in the womb. These types of heart conditions are called congenital heart defects because a child is born with them. Some examples of these defects include holes in the walls of the heart or problems with the valves.

While a baby is still in the womb, a congenital heart condition is not dangerous because the baby's heart and lungs function differently than they do after delivery. Until the umbilical cord is cut and the baby takes his first breath, he or she receives oxygen through the placenta, not his or her lungs. After delivery, a baby's lungs will begin to function normally as the passages that allowed your baby to receive oxygenated blood in the mother's womb close.

At Children's Hospital Colorado's Heart Institute, we are experts in treating all types of congenital heart defects. Some of the most common are ventricular septal defects, atrial septal defects and hypoplastic left heart syndrome.

Another type of heart condition we treat at Children's Colorado are acquired heart conditions. These occur when the heart is formed normally in the womb, but something happens after a baby is born that causes the heart to pump poorly or alters the normal beating rhythm of the heart.

Adults are more at risk for acquired heart conditions because they've been using their hearts for a lot longer than kids. Heart disease and high blood pressure are common adult acquired heart conditions. However, sometimes a child can get a viral or bacterial infection that changes their normal heart function and must be treated.

Please look through the list of conditions we treat to find more specific information about the condition that may be affecting your child.

Helpful links

Want to learn more about the heart? Visit: