How does the heart works?
The heart is a muscle that pushes blood through the body to deliver oxygen and nutrients. The heart also removes waste products. It works by pumping blood through a network of vessels called the circulatory system. The circulatory system includes arteries to send blood with oxygen away from the heart into the body and veins to bring blood without oxygen blood back to the heart.
The heart is also responsible for maintaining a standard heart rate and blood pressure. Its electrical system, made up of specialized cells called pacemaker cells, helps control the heart rate and ensure that blood pumps effectively.
Basic anatomy of the heart
The human heart is an organ located in the chest, behind the breastbone (sternum) and between the lungs. The heart is divided into two halves, right and left, that work together to oxygenate blood and pump it to the body. Each half is made up of two chambers, atria and ventricles, that direct blood flow.
This section should include an image and brief description of the blood flow through each chamber.
The heart’s four chambers include the left and right atria and the left and right ventricles. The atria are the heart’s two upper chambers that push blood to the ventricles, while the ventricles are the two lower chambers that push blood out of the heart.
- The right atrium: receives blood without oxygen from the body and pumps it into the right ventricle.
- The right ventricle: pumps the blood into the lungs, where it is oxygenated.
- The left atrium: receives blood with oxygen from the lungs and pumps it into the left ventricle.
- The left ventricle: the strongest chamber of the heart, the left ventricle pumps oxygenated blood to the rest of the body.
The heart has four valves that help direct blood flow within it, the tricuspid valve, the pulmonic valve, the mitral valve and the aortic valve.
- Tricuspid valve: found between the right atrium and ventricle. It prevents blood from flowing back into the right atrium when the right ventricle contracts.
- Pulmonic valve: found between the right ventricle and the lungs. It prevents blood from flowing back into the right ventricle when the lungs expand to receive blood.
- Mitral valve: found between the left atrium and left ventricle. It prevents blood from flowing back into the left atrium when the left ventricle contracts.
- Aortic valve: found between the left ventricle and the aorta. It prevents blood from flowing back into the left ventricle when the aorta expands to distribute blood to the rest of the body.
Each of these valves have flaps called “leaflets” that open and close to direct blood flow within the heart. When the heart contracts, the valves open to allow blood to flow through. When the heart relaxes, the valves close to prevent blood from flowing backward.
What is a normal heartbeat in children?
An average resting heart rate is the number of times the heart beats per minute at rest. A normal heartbeat in children is usually characterized by a regular rhythm and a rate within a specific range, determined by a child’s age.
The following are general guidelines for average resting heart rates by age:
- Newborns: 70 to 190 bpm
- Infants: 80 to 130 bpm
- Children aged 1 to 5 years: 80 to 120 bpm
- Children aged 6 to 15 years: 70 to 110 bpm
- Adults (aged 16 and older): 60 to 100 bpm
It is important to note that these ranges are general guidelines and may vary based on individual differences and other factors, such as activity level and underlying medical conditions.
What is normal blood pressure in children?
Blood pressure is the measure of the force blood creates against artery walls as it pumps through the body. Normal blood pressure in children varies based on the age, size and gender of the child. The following are general guidelines for normal blood pressure in children:
- Newborns: 70/50 mmHg to 95/60 mmHg
- Infants: 70/50 mmHg to 95/65 mmHg
- Children aged 1 to 5 years: 85/50 mmHg to 110/65 mmHg
- Children aged 6 to 11 years: 90/55 mmHg to 120/70 mmHg
- Children aged 12 to 19 years: 95/60 mmHg to 130/80 mmHg
A child’s blood pressure may be higher or lower than the average range for their age.
Types of heart conditions in children.
Heart conditions are among the most common birth defects in the United States, affecting about 1 in every 100 children. Heart conditions can be congenital (present at birth) or acquired (developed after birth). Congenital heart conditions range from mild to severe and are the most common type of birth defect. Acquired heart conditions, on the other hand, can occur at any age and can be caused by various factors, including underlying medical conditions, infections, and lifestyle factors.
Congenital Heart Defects
Congenital heart defects are structural abnormalities present at birth that can affect the normal functioning of the heart. They are the most common birth defect, affecting about 1% of newborns. The experts at the CHOC Heart Institute
work with pediatric patients and their families to diagnose, treat and manage congenital heart disease.
Some common congenital heart defects in children include:
- Aortic stenosis: a condition in which the aortic valve, which controls blood flow from the left ventricle to the aorta, becomes narrowed or obstructed, leading to reduced blood flow.
- Atrial septal defect: a hole in the wall between the heart’s two upper chambers, allowing oxygen-rich and oxygen-depleted blood to mix.
- Coarctation of the aorta: a narrowing of the aorta, the main artery that carries blood from the heart to the body.
Acquired Heart Conditions
Acquired heart defects develop after birth and may be caused by other medical conditions, medications and other lifestyle factors.
Some common acquired heart defects in children include:
- Kawasaki disease: inflammation of the blood vessels that can result in damage to the coronary arteries.
- Rheumatic heart disease: the result of rheumatic fever scarring heart valves to the point where they may not function properly.
- Coronary artery disease: coronary arteries, that supply oxygen-rich blood to the heart, become narrowed or blocked, causing reduced blood flow to the organ. This condition is more common in older children and adolescents.
- Cardiomyopathy: the heart muscle becomes damaged or weakened, leading to reduced pumping function.
Congenital or Acquired Heart Conditions
There are cardiovascular conditions in children that can occur either congenitally or be acquired in childhood. Some of these more common heart conditions include:
- Arrhythmias: Abnormal heart rhythms that can range from harmless to potentially life-threatening. They can be caused by various factors, including underlying medical conditions, medications and lifestyle factors.
- Pulmonary Hypertension: Elevated blood pressure in the pulmonary artery, which carries blood from the heart to the lungs, causing the right side of the heart to work harder to pump blood. This can eventually lead to damage of the heart muscle.
How common are heart conditions in children?
Heart conditions are among the most common birth defects in the United States, affecting about 1% of newborns or about 1 in every 100 children (CDC, 2016
). Congenital heart defects
are structural abnormalities present at birth that can affect the normal functioning of the heart. They range from mild to severe and may require surgical or other medical treatment.
Acquired heart conditions are less common in children. Children treated for a congenital heart defect have an increased risk of acquiring heart diseases like cardiomyopathy, endocarditis and arrhythmias during childhood.
Risk factors for heart conditions in children
There are several risk factors that may increase the likelihood that a child will be diagnosed with a heart condition. Some risk factors are present at birth, while others may develop later in life.
Risk factors for congenital heart defects may include:
- Family history of heart defects
- Maternal age (older mothers are at higher risk)
- Maternal diabetes
- Maternal substance abuse (including tobacco, alcohol, and illegal drugs)
- Maternal infections (such as rubella or cytomegalovirus)
- Maternal exposure to certain medications or environmental toxins
- Certain genetic disorders are associated with heart defects.
Risk factors for acquired heart conditions may include:
- Overweight or obesity
- Physical inactivity
- High blood pressure
- High cholesterol
- Family history of heart disease
- Genetic conditions
- Tobacco use
- Alcohol abuse
- Illegal drug use
Having one or more of these risk factors does not mean a child will develop a heart condition. Many children with heart conditions do not have any known risk factors.
Can a child have heart disease?
Yes, children can have heart disease. It can be present at birth or can develop later in life.
The main difference between heart disease and heart conditions is that heart disease is typically used to describe more severe or advanced stages of heart problems. In contrast, heart conditions can refer to any disorder or abnormality affecting the heart. Heart conditions may or may not progress to heart disease.
Can you prevent heart disease in children?
Several steps can be taken to reduce the risk of heart disease in children.
Here are some general recommendations.
- Encourage a healthy diet: A diet rich in fruits, vegetables, whole grains and lean protein and low in saturated and trans fats can help maintain a healthy weight and blood pressure, which can help prevent heart disease.
- Encourage regular physical activity: Regular physical activity can help maintain a healthy weight, improve cardiovascular health and reduce the risk of heart disease. Children should participate in at least 60 minutes of moderate to vigorous physical activity daily.
- Avoid tobacco and smoke exposure: Tobacco use and exposure to secondhand smoke can increase the risk of heart disease. Children should be encouraged to avoid tobacco products and to stay away from areas where smoking is allowed.
- Encourage healthy habits: Children should be encouraged to brush their teeth twice a day, wash their hands frequently and get plenty of sleep to help maintain good overall health and reduce the risk of heart disease.
Symptoms of heart conditions in children
The symptoms of heart conditions in children can vary depending on the specific disorder and its severity. Some common symptoms of heart conditions in children may include:
- Shortness of breath: Children with heart conditions may have difficulty breathing, especially during physical activity or when lying down.
- Chest pain: Children with heart conditions may experience chest pain ranging from mild to severe.
- Rapid or irregular heartbeat: Children with heart conditions may have an abnormal heart rhythm, which can cause the heart to beat fast, slow or irregularly.
- Dizziness: Children with heart conditions may feel lightheaded or dizzy, especially when standing up or changing positions.
- Fatigue: Children with heart conditions may feel tired or weak, even after resting.
- Swelling: Children with heart conditions may have swollen ankles, feet, legs or abdomen due to fluid buildup.
Can a child have a heart attack?
Although rare, children can have a heart attack, often caused by congenital heart defects or underlying medical conditions, such as Kawasaki disease or rheumatic fever. In rarer cases, children’s heart attacks can be caused by other factors, such as trauma or substance abuse. Symptoms of a heart attack in children may include chest pain, shortness of breath, nausea, vomiting and fatigue.
When to see a doctor for heart condition symptoms
If a child is experiencing any symptoms related to a heart condition, it is important to see a healthcare provider for evaluation and treatment. Some common symptoms of heart conditions in children may include shortness of breath, chest pain, rapid or irregular heartbeat, dizziness, fatigue and swelling.
It is important to seek medical attention if a child is experiencing any of these symptoms, especially if they are severe or persistent. Early diagnosis and treatment of heart conditions can help prevent complications and improve outcomes.
Screening and diagnosis for heart conditions in children.
There are several methods used to screen and diagnose heart conditions in children. The specific screening and diagnostic methods used may depend on the child’s age, symptoms and medical history, as well as their specific heart condition.
Some common screening and diagnostic methods used to evaluate heart conditions in children may include:
- Cardiac catheterization: This test involves inserting a thin tube (catheter) into a blood vessel in the arm or leg. From there, it is threaded it to the heart. Cardiac catheterization helps assess the function of the heart to diagnose a condition.
- Echocardiogram: Sound waves create a detailed image of the heart to help diagnose heart conditions including structural abnormalities and heart valve problems.
- CT scan: A computed tomography (CT) scan that uses x-rays to create detailed images of inside the body to evaluate various conditions in children.
- Cardiac MRI: A cardiac magnetic resonance imaging (MRI) scan is a diagnostic test that uses a magnetic field and radio waves to create detailed pictures of the heart and its surrounding structures.
- Electrocardiogram and cardiac stress testing: An ECG can be used to evaluate various heart conditions in children, including arrhythmias (abnormal heart rhythms) and structural abnormalities. A cardiac stress test is a type of ECG performed while the heart works harder than usual. It evaluates how well the heart functions during physical activity and can diagnose certain conditions.
- Holter monitoring: Holter monitoring is a diagnostic test that records the heart’s electrical activity over time. It is typically used to evaluate heart conditions that may not be detected during a standard electrocardiogram (ECG), such as arrhythmias (abnormal heart rhythms) that come and go or only occur during certain activities.
Heart Institute at CHOC
Children should see a healthcare provider regularly to ensure that their heart is functioning correctly. Visits may include regular check-ups, as well as monitoring and management of any underlying medical conditions that could affect the heart. At CHOC, our highly specialized and board-certified pediatric cardiology team and cardiothoracic surgeons are committed to providing the least invasive, most advanced treatment for heart-related problems in children.