Pediatric Cardiology

Pediatric cardiology is the branch of medicine concerned with the diagnosis and treatment of heart diseases and, to some extent, circulatory system disorders in children from the prenatal period up to 18 years of age. It also aims to prevent heart diseases in high-risk groups. The heart and vascular system are among the first organs to develop in the womb; they begin forming as a tube in the third week and, by about the second month, take on a shape very similar to that at birth, entering into continuous function. This process does not always proceed perfectly, and certain problems can occur. These structural and rhythm-related issues affect approximately 1 in every 100 live births (0.8–0.9%). With technological advances, it has become possible to detect such problems, even in the womb. Diagnosing and managing these conditions prenatally is a team effort between the obstetrician and the pediatric cardiologist. After birth, the management of each condition varies from patient to patient, and treatment is highly individualized. While some cases resolve spontaneously, others require serious intervention. The causes of heart disease in children vary greatly—from genetic factors, infections, negative environmental influences, chemicals, and medications—though in many cases, the cause cannot be determined.

Common Heart Diseases in Children

The most common heart diseases in children are congenital, such as holes in the heart, narrowing of valves and vessels, abnormalities in the number, position, or shape of the chambers, and arrhythmias. Acquired heart diseases also occur, including rheumatic heart disease, pericardial effusion, cardiomyopathies, and diseases of the coronary arteries (such as Kawasaki disease). In recent years, COVID-19 has also been seen to affect all layers of the heart and its rhythm at a relatively significant rate.

Signs and Symptoms of Heart Disease in Children

Because the causes and types of heart diseases are so varied, the symptoms can differ greatly in timing and severity. Some conditions present only with subtle findings detectable during a medical examination, while others cause life-threatening symptoms requiring urgent intervention, such as cyanosis. Common signs include:

• Fatigue
• Sweating
• Cyanosis (bluish skin)
• Failure to gain weight
• Edema
• Rapid breathing
• Labored breathing or shortness of breath
• Frequent illnesses
• Heart murmur
• Palpitations
• Dizziness
• Fainting
• Chest pain
• High blood pressure
• Growth delay

Causes of Heart Disease in Children

Childhood heart diseases can be broadly divided into congenital and acquired. Congenital heart diseases are more common in children, whereas acquired heart diseases predominate in adults.

Congenital Heart Diseases and Their Causes

These include malposition of the heart (e.g., located on the right), abnormal arrangement or connection of chambers, holes in the septa, absent, narrowed, or insufficient valves, narrowing, dilation, absence, or abnormal opening of vessels, abnormal heart-lung connections, myocardial or pericardial abnormalities, and arrhythmias. Possible causes include:

Genetic Factors – Around 0.8–0.9% of newborns are born with heart disease, and about 10% of these are due to genetic problems. Down syndrome is the most common genetic condition, with about half of affected children having heart disease. Advances in genetics have identified many other syndromes (DiGeorge, Williams, Noonan) with chromosomal defects (microdeletion, translocation, duplication) responsible for heart disease. Genetic counseling is often provided before or during pregnancy.

Metabolic Disorders – Maternal diabetes or gestational hyperglycemia accounts for 1–2% of all newborn heart diseases. Babies of diabetic mothers have a 2–6% risk of heart defects. Maternal weight gain and blood sugar during pregnancy can also affect the baby’s future risk for hypertension, diabetes, and cardiovascular disease.

Infections – Maternal infections during pregnancy, such as rubella, CMV, toxoplasmosis, and herpes, can harm the fetal heart. COVID-19 has also been shown to negatively affect fetal heart health.

Teratogenic Factors – Smoking, alcohol, drug use, radiation, exposure to chemicals, and certain medications during pregnancy can cause congenital heart disease. Environmental pollution and maternal diet/air quality also play a role.

Medications – Some medications taken before or during pregnancy may cause heart-related problems in the baby.

Diagnostic Methods in Pediatric Cardiology

Echocardiography (ECHO) – The most common, non-invasive method, essentially an ultrasound of the heart. Can be performed transthoracically or via transesophageal probe. Modern devices include color Doppler, and 2D, 3D, and 4D imaging options.

Electrocardiography (ECG) – Records the heart’s electrical activity through electrodes placed on the chest. Useful for assessing rhythm and function; painless and quick.

Holter ECG – A 24-hour continuous ECG recording for detecting intermittent rhythm problems, syncope, or unexplained fatigue and shortness of breath.

Cardiac Catheterization and Angiography – Invasive procedures used both for diagnosis and treatment (e.g., closing septal defects, opening narrowed valves/vessels).

Telecardiography – Chest X-ray assessment of heart size, position, and pericardial conditions; less commonly used today.

Electrophysiology Studies – Used to diagnose and treat arrhythmias by recording intracardiac electrical signals.

Exercise (Stress) Testing – Uses treadmill or bicycle to assess the heart’s response to increased workload, diagnose certain conditions, or evaluate treatment effectiveness.

When Should a Child See a Pediatric Cardiologist?

If a pediatrician suspects a heart problem during an exam, if any of the above symptoms are present, if prenatal ultrasound shows abnormalities, if there’s a family history of early heart disease or sudden death, or if the child has syndromes linked to heart defects (e.g., Down syndrome).

Common Reasons for Referral

• Known or suspected heart disease
• Detection of a murmur
• Cyanosis, chest pain, fainting, palpitations
• Risk factors for heart disease

Murmur - Abnormal heart sounds heard with a stethoscope. May be “innocent” (no structural defect) or “pathologic” (due to septal defects, vessel narrowing, or valve disease). ECHO is used for definitive diagnosis.

Chest Pain - Common in children but rarely cardiac in origin. Cardiac causes include hypertrophic cardiomyopathy, valve disease, pericardial effusion, coronary anomalies, and myocarditis. COVID-19 has been linked to cardiac chest pain in some cases.

Infective Endocarditis - Infection of the heart’s inner lining, more common in children with structural defects or previous heart surgery. Prevention focuses on oral hygiene and prophylactic antibiotics before certain procedures.

Evaluation of Children in Sports

Most heart-related problems occur when the heart is under increased load, such as during exercise. Risk assessment before sports participation is essential, especially for high-risk groups (family history of early heart disease or sudden death, structural heart disease, arrhythmias, cardiomyopathy, Kawasaki disease). Evaluation includes ECHO, and if needed, stress testing and Holter monitoring. Annual cardiology check-ups are recommended for children engaged in intensive sports.