Normal Heart Part II

Many centuries ago, people believed that their emotions came from their hearts, because the heart beats faster when the person is excited or scared. We now know that our emotions originate in the brain, and in this case, the brain tells the heart to speed up. So, what is the heart up to? What does it look like? Let's find out.

The heart is composed of cardiac muscle, which is found only within this vital organ. The human embryonic heart begins beating at around 21 days after conception. At that point, it will keep beating, without a break, for a lifetime. Is that not amazing? A child's heart beats about 150,000 times each day.

The Heart Is A Pumping Organ

The heart is a pumping organ that intakes non-oxygenated blood through the major veins, delivering it to the lungs for oxygenation, and then pumping it into the body through the main artery, the aorta. In children, the heart is about the size of a small fist that delivers a very powerful punch. It could be a knockout in round one. Luckily for us, it contains a buffer zone to decrease its force or we would be shaking with each heartbeat. The heart is enclosed by a sac known as the pericardium and is surrounded by the lungs. In most children, the heart is usually situated in the middle of the chest, with the largest part of it being slightly offset to the left, underneath the breastbone (sternum). The heart is usually felt to be on the left side of your chest because the left heart (left ventricle) is pumping much stronger than the right.

Heart Sounds

When someone listens to your heart with a stethoscope, the sound is often described as lub-dub, lub-dub. The first heart sound (lub) is caused by the acceleration and deceleration of blood and a vibration of the heart at the time of the closure of the tricuspid and mitral valves. The second heart sound (dub) is caused by the same acceleration and deceleration of blood and vibrations at the time of closure of the pulmonary and aortic valve.

You Have A Pulse

Even though your heart is inside your chest, there is an easy way to know that it is working from the outside. It is your pulse. You can find your pulse by lightly pressing on the skin anywhere there is a large artery running beneath your skin. It is easy to check your pulse on the side of your neck at its mid-portion. You may also check it inside of your wrist, just below the thumb. You will know that you have found your pulse when you feel a small beat under your skin. Each beat is caused by the pumping of your heart. In children, the heart usually beats between 60-160 beats per minute, while the child is awake. If a child is running, it could go as fast as 210 beats per minute and will gradually go down as soon as they stop exercising. In adolescents who are asleep, the heart may slow down to 45 beats per minute. In well-trained athletes, it could slow down to 35 beats per minute or even slower during sleep.

Blood Circulation

The human body has about six quarts of blood that circulate through the body three times every minute. In one day, the blood travels about 12,000 miles. That is four times the distance across the United States from coast to coast. The heart pumps about one million barrels of blood during an average lifetime, which would be enough to fill more than three supertankers.

Keep Your Heart Healthy

Children are born with a healthy heart and it is important to keep it in good shape. There are some things that can be done to keep your heart healthy.

  • The human heart is a pump compiled of cardiac muscle. If you want it to be strong, you need to exercise it. Biking with a helmet, swimming, and walking uphill are excellent healthy activities. You should try to be active every day for at least 30-45 minutes.
  • Eat healthy. Avoid soft drinks, sweets (simple sugars), white bread, and fast food. Try to eat plenty of vegetables and add fruit to your diet. If you are overweight, you may use a salad plate instead of a full sized plate. Do not add too much salt to your diet. One to two teaspoons per day may be enough for most of us. You need to eat food rich in potassium such as bananas, tomatoes, broccoli, etc...
  • Please do not smoke, as it damages your heart, blood vessels, and lungs. Your lungs will turn from a pink color to a dark gray or black color (just like tar).

A Normal Heart

Our Mission

Children's Heart Specialists, PSC is committed to provide comprehensive pediatric cardiac services to infants, children and young adults. We strive to insure the highest quality in non-invasive cardiovascular testing. Our medical staff is committed to being board certified in pediatric cardiology and adult congenital heart disease.

Our goal is to provide the highest quality of care with compassion and respect to our patients and their families.

Accredited in Echocardiography


We do not give any medical advice or recommendations about you or your child's health in this website. The medical information that appears on this website is to be used as a general guide about heart defects and symptoms. Medical advice is discussed at the time of your consultation with Dr. Villafañe.