By Angela Ryan Lee, MD
Published on December 15, 2021
Medically reviewed by Jonathan B. Jassey, DO
Pediatric heart failure is a broad term including any condition in which an infant’s, child’s, or adolescent’s heart is not able to sufficiently fill or pump blood to the body. This results in a range of symptoms due to a backup of blood in some organs and lack of blood flow to others.
This article discusses the symptoms and causes of pediatric heart failure, as well as its diagnosis and treatment.
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Structure and Function of the Heart
The heart is a complex organ that can be thought of as a two-sided pump with four chambers. Its job is to pump blood to supply oxygen to the body.
The two upper chambers, called atria, collect blood from the major veins. In order to prevent mixing of blood, the right and left atria are separated by a membrane known as the interatrial septum.
The two lower chambers, called ventricles, are muscular pumps that squeeze blood out to the major arteries. The ventricles are separated by the ventricular septum to prevent mixing of blood.
The heart also has four valves. The mitral and tricuspid valves separate the atria from the ventricles. The aortic and pulmonic valves separate the ventricles from the great blood vessels.
The Heart: Anatomy, Function, and Conditions
Blood Flow
The path of blood in the body is as follows:
The right atrium collects deoxygenated blood (blue in the diagram below) from the major veins. It passes through the tricuspid valve into the right ventricle.
The right ventricle pumps blood through the pulmonic valve to the lungs to collect oxygen.
From there, the newly oxygenated blood collects in the left atrium (orange in the diagram below) and passes through the mitral valve into the left ventricle.
With each heartbeat, the left ventricle squeezes and pumps the oxygenated blood out through the aortic valve into the aorta, the body’s largest blood vessel.
From the aorta, blood is carried to the entire body, where it delivers oxygen and vital nutrients to tissues.
Verywell / Alex Dos Diaz
Pediatric Heart Failure Symptoms
Symptoms of heart failure in children are related to the backup of blood in the lungs and body, as well as inadequate blood flow to the body’s organs.
The primary symptoms include:1
Rapid breathing or shortness of breath
Feeding and growth problems
Changes in skin color or temperature
Decreased exercise tolerance
Fatigue
Swelling of the legs, ankles, or eyelids
Cold, pale extremities
Abdominal pain, nausea
Palpitations
Symptoms vary depending on the child's age and cause of heart failure.
For example, an infant with a congenital abnormality may have feeding intolerance, rapid breathing, and poor growth in the first few days of life. An adolescent with weakened heart muscle from a viral infection may experience decreased exercise tolerance and fatigue as the main symptoms.
Causes
Most heart failure in children is caused by either congenital abnormalities of the heart or by primary cardiomyopathy. Primary cardiomyopathy is a weakness of the heart due to problems in the heart muscle itself. It may be inherited.
Some heart abnormalities are obvious at birth, but others may go undetected for years before causing symptoms of heart failure.2
Congenital Abnormalities
The heart is a complex organ that undergoes many changes during embryonic development.
Defects of the heart can occur due to problems with fusion of the heart’s walls (or septum) resulting in a “hole in the heart.” Abnormal connections between chambers can form, or chambers and valves may not properly form. These can result in mixing of oxygenated and deoxygenated blood, with less efficient oxygen delivery to the body.
In addition, shunts or abnormal passages can form that overload the heart, since more blood is passing through than otherwise should. This eventually leads to heart failure.
Some congenital abnormalities that can lead to heart failure include:
Atrial septal defect
Ventricular septal defect
Transposition of the great arteries
Tetralogy of Fallot
Single ventricle
Ebstein anomaly
Patent ductus arteriosus
Coarctation of the aorta
Congenital valve disease
Coronary artery abnormalities that impair blood supply to the heart muscle itself
Primary Cardiomyopathies
Cardiomyopathy refers to an abnormal heart muscle. It is another major cause of pediatric heart failure.
A weakened heart muscle does not properly relax to accommodate blood filling the chambers, or it may not properly pump blood out of the heart.
Primary cardiomyopathy is a condition in which the heart muscle itself is abnormal. This can be due to inherited mutations in the heart muscle, disorders of metabolism, and muscular dystrophies.
The following are examples of primary cardiomyopathies:
Noncompaction cardiomyopathy
Hypertrophic cardiomyopathy
Arrhythmogenic right ventricular cardiomyopathy
Neuromuscular disorders such as muscular dystrophies
Glycogen storage disorders (Pompe disease)
Arrhythmias
Arrhythmias, or abnormal heart rhythms, can be the cause of heart failure and a result of heart failure.
Some arrhythmias cause rapid heart rate, or tachycardia. Over time, tachycardia can cause the heart muscle to weaken and lead to heart failure. This type of heart failure is generally reversible when the underlying heart rhythm problem is treated.
Other arrhythmias, like complete heart block, cause abnormally slow heart rate, or bradycardia, that can also cause heart failure in children.2 Treatment involves implantation of a pacemaker.
Infection
Various types of infection can cause heart failure. Viral myocarditis, or heart inflammation due to viral infection, can cause rapid and severe heart failure symptoms.
While rare in the United States, parasitic infection and rheumatic heart disease are more common causes of heart failure in other parts of the world.
For example, a parasitic infection in Central and South America causes Chagas disease and leads to heart failure and heart rhythm problems. Rheumatic fever is caused by bacterial Streptococcus infection.
Nutritional Deficiency
Severe deficiency of Vitamin B1, also known as thiamine, is a well-documented cause of cardiomyopathy that is exceedingly rare in children in the United States. Severe protein deficiency and carnitine deficiency can also cause cardiomyopathy.3
While nutritional deficiency is a rare cause of heart failure in the United States, malnutrition is not uncommon in children who have heart failure due to poor appetite and nutrient absorption.4
Toxins
Exposure to certain drugs or medications can cause direct toxicity to the heart. For example, a class of chemotherapy medication called anthracycline can damage the heart muscle and cause heart failure.
Diagnosis
Diagnosing heart failure in children is accomplished through a combination of medical and family history, symptom review, physical examination, and multiple complementary tests.
Chest X-Ray
Chest X-ray is often the first test a healthcare provider will order to evaluate shortness of breath. The heart may appear enlarged, and signs of congestion in the blood vessels in the lungs, or fluid in the lungs, can be seen.
Certain congenital abnormalities can also be indicated through a chest X-ray. Follow-up tests are necessary for further diagnosis.
Echocardiogram
The main test for diagnosing heart failure is a type of ultrasound called a transthoracic echocardiogram. An ultrasound probe is guided over the chest to obtain images of the heart and information about blood flow.
An echocardiogram provides a great deal of information about the heart’s structure and function. It can diagnose a weak heart muscle, heart valve problems, abnormal connections between the heart’s chambers, and other congenital abnormalities.
Laboratory Tests
Cardiac biomarkers can be tested in the blood and, if elevated, help to differentiate heart failure from other causes of shortness of breath.
Lab tests for blood counts, electrolytes, kidney and liver function, and thyroid tests are routinely done to evaluate for complications or causes of heart failure.
When cardiomyopathy is discovered, genetic tests can be done to look for the specific cause. This is especially helpful when heart failure occurs in several family members over generations. If a genetic mutation is discovered, testing other relatives is recommended.
Electrocardiogram
Electrocardiogram (ECG) is a test performed to evaluate the heart’s rhythm and can give clues about the cause of heart failure.
ECG is a quick, noninvasive test in which electrodes are placed on the chest. A printout of the heart’s electrical activity provides information about the heart’s rhythm. In addition, certain patterns on the ECG can suggest particular causes of heart failure.
Sometimes ambulatory heart monitoring is necessary to evaluate the heart’s rhythm over a longer period of time. A Holter monitor is one such example; it uses electrodes attached with wires to a small box that can be worn for a couple of days. Another type of monitor uses a patch that can stay on for up to two weeks.
Cardiac MRI
Cardiac MRI is a special imaging test that uses a strong magnet to create images of the heart.
MRI does not require any radiation and is not painful or invasive, but some people feel claustrophobic in the MRI scanner. Sedation may be given in some cases.
MRI can provide diagnostic information about some cardiomyopathies, as well as give information about abnormal shunting of blood in certain congenital abnormalities.
Cardiac Catheterization
Cardiac catheterization is an invasive test in which catheters are guided to the heart through blood vessels. This test provides information about pressure in the heart’s chambers and the cardiac output.
X-rays and special dye called iodinated contrast are used to visualize structures, including the coronary arteries that feed the heart.
The information gained from cardiac catheterization is helpful in surgical and transplant planning.
Endomyocardial Biopsy
Sometimes diagnosing heart failure in children requires taking a tissue sample. Endomyocardial biopsy is a procedure in which a small piece of heart tissue is removed during a cardiac catheterization. It is then viewed under a microscope by a pathologist.
This procedure carries some risk, but can provide valuable information to arrive at a definitive diagnosis and treatment plan.
Treatment
Treatment of pediatric heart failure involves correcting the underlying cause, optimizing the heart’s function, addressing heart failure symptoms, and delaying the progression of heart failure.
Many congenital abnormalities that cause heart failure can be corrected with surgery. In the last several decades, we have seen amazing progress in surgical techniques, and some conditions that were previously fatal are now able to be treated surgically.
Some cardiomyopathies, on the other hand, are not reversible and lead to longstanding heart failure. In these cases, medications are given to help optimize the heart’s function, control symptoms, and delay progression of heart failure.
While the promising effects of heart failure medication are not as well-defined for children as they are in adults with heart failure, newer medications have shown some promise, specifically for children with heart failure.35
Implantable cardiac devices such as a pacemaker or defibrillator may be recommended for select children with heart failure to treat complete heart block or prevent sudden cardiac death, respectively.
Heart Transplants
Heart transplant may be considered for severe, irreversible heart failure. A team of healthcare providers will evaluate and provide support every step of the way in this process.
Summary
Pediatric heart failure is a serious condition in which the heart is not able to adequately perform its function in supplying blood to the body. This can lead to a range of symptoms. Congenital heart disease is the most common cause of pediatric heart failure in the United States, followed by primary cardiomyopathy.
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