Paediatric Cardiology

Result from anomalies in the heart’s development during the foetal stage. The most common defects include:

•    Ventricular septal defect (VSD) and Interventricular septal communication (ISC): Abnormal openings between the heart chambers that allow blood to flow between them, which may cause cardiac and pulmonary overload.

•    Patent ductus arteriosus (PDA): Abnormal persistence of the foetal connection between the aorta and pulmonary artery after birth, leading to abnormal blood flow, potentially causing cardiac and pulmonary overload.

•    Tetralogy of Fallot: Complex congenital heart defect comprised of four structural heart changes that compromise blood oxygenation.

•    Coarctation of the aorta: Narrowing of the main artery of the body, which restricts blood circulation and puts extra strain on the heart.

•    Atrioventricular septal defect (AVSD): Congenital cardiac malformations that affect the walls and valves at the centre of the heart, often associated with Down Syndrome.

Genetic heart conditions are a group of cardiovascular disorders caused by inherited anomalies or genetic mutations, which may affect the structure of the heart, the heart muscle, the heart rhythm or major blood vessels. In many cases, these conditions can appear in childhood, adolescence or adulthood, even in people with no apparent symptoms.

The main inherited heart conditions include:

•    Cardiomyopathies: affect the heart muscle and can weaken the heart’s pumping action;

•    Channelopathies: electrical heart diseases that increase the risk of potentially serious arrythmias;

•    Heritable thoracic aortic disease: associated with changes in the aortic wall that require specialised lifelong monitoring.

Some genetic syndromes are also associated with a greater risk of congenital heart defects and other cardiovascular changes. This is the case with Down syndrome, which is often related with congenital heart conditions, and Williams syndrome, which can be associated with changes in blood vessels and circulation.

Identifying these conditions early is vital to enable the right care, guide treatment and reduce the risk of complications.

Paediatric hearts can also be affected by conditions that appear after birth and can impact different structures:

•    Valves: rheumatic fever, endocarditis
•    Myocardium: myocarditis
•    Pericardium: pericarditis
•    Coronary arteries: Kawasaki disease

Unlike adults, whose heart conditions are mostly acquired and associated with risk factors and natural deterioration, children predominantly have congenital heart conditions. However, genetic heart conditions and acquired heart conditions can also emerge during childhood and adolescence.

Transthoracic echocardiogram (TTE) is an imaging test that uses ultrasound to observe the child’s heart and major vessels in real time. TTE is performed by moving a small probe over the chest, applying a conductive gel that ensures clear imaging.

This test helps assess the heart’s anatomy and function, including the heart chambers, valves, the heart muscle and how blood circulates inside the heart. In current clinical practice, transthoracic echocardiogram combines various forms of examination, such as two-dimensional imaging, M-mode and Doppler.

Using the Doppler technique makes it possible to analyse the direction and speed of blood flow, which is essential to identify changes in circulation, constrictions, changes in heart valves, or abnormal communication between heart chambers.

As this is a painless and non-invasive test that does not employ radiation, it is widely used in Paediatric Cardiology to diagnose, monitor or rule out heart disease in babies, children and teenagers.

Foetal echocardiogram is an imaging test that uses ultrasound to provide a detailed assessment of a baby’s heart during pregnancy. This technology enables the heart’s anatomy and function to be examined, as well as an analysis of blood flow using the Doppler technique, to help achieve an early diagnosis of most congenital heart defects.

This test is painless, non-invasive and considered safe for the mother and foetus. It is usually performed between 18 and 24 weeks of pregnancy, the stage that allows a more comprehensive assessment of the heart’s development, although the test can also be carried out earlier or later, depending on the clinical situation.

In some cases, factors such as the baby’s position, the gestational age or the mother’s physical characteristics can create temporary difficulties to visualize the foetus, sometimes making it necessary to repeat the test.

Following the foetal echocardiogram, the results are explained to the pregnant mother and shared with the attending physician. If any change is identified, the monitoring process is coordinated with the Paediatric Cardiology team.

Prenatal diagnosis makes it possible to plan for antenatal care, childbirth and care for the newborn, ensuring that, if necessary, the baby is born in a centre with specialised care in Paediatric Cardiology and Paediatric Cardiac Surgery.

Electrocardiogram (ECG) is a non-invasive diagnostic test that allows the child’s heart’s electrical activity to be assessed, identifying changes in rhythm and cardiac conduction.

This is one of the most common tests used for pre-participation sports screening, as part of the clinical assessment of children and teenagers that participate regularly in sports activities. ECG is able to identify heart disorders associated with a greater risk of sudden death during exercise and which justify further investigation.

The test is simple, quick and painless. Small electrodes are attached with adhesive patches to the child’s chest, wrists and ankles, to detect the electrical signals produced by the heart. The signals are recorded by the ECG device and converted into a visual graph (waves) that allows the physician to analyse the heart’s electrical activity.

A 24-hour Holter Monitor is a test that allows continuous monitoring of the baby, child or adolescent’s heart’s electrical activity during an extended period, usually 24 hours, although it can be continued for longer when clinically indicated. This device is used to assess the heart rhythm throughout the day and night, at different times during the child’s daily routine.

The test is carried out by placing small electrodes on the chest, connected to a portable monitor that records the heart rhythm throughout the day and night, including during physical activities, rest and sleep.

Unlike an Electrocardiogram (ECG), which only records the heart’s electrical activity for a few seconds, the Holter monitor allows continuous recording over several hours. This extended assessment increases the likelihood of identifying changes in heart rhythm or cardiac conduction that may only occur sporadically.

This is a painless, non-invasive and safe test, and it is especially helpful to investigate palpitations, dizziness, fainting spells or suspected arrhythmias.

A Stress Test (Exercise ECG) is a diagnostic test that assesses the child’s cardiovascular response to controlled physical exercise.

It involves continuous Electrocardiogram (ECG) recording and regular blood pressure monitoring while the child performs a standardised exercise, usually on a treadmill, with a gradual increase in speed and inclination.

This test is particularly useful to investigate symptoms related to physical exertion, allowing the heart’s electrical activity to be analysed before, during and after exercise, identifying changes that may not be detected at rest.

This is a non-invasive test that lasts around 20 to 30 minutes. The child should wear comfortable clothing and shoes, suitable for walking, and does not need to fast beforehand, unless otherwise advised by the physician.

A Cardiac Event Monitor is a complementary diagnostic test that employs a portable device to record the child’s heart’s electrical activity, only when symptoms occur or when the device is automatically activated by certain alterations in the heart rhythm. The test takes between 7 and 14 days and is performed on an outpatient basis.

It is especially indicated to study sporadic symptoms with a likely cardiac origin, namely:

• Palpitations, with suspected paroxysmal arrhythmias

• Syncope, presyncope or lipothymia spells (fainting and dizziness)

• Sporadic complaints of chest pain or discomfort

This type of extended monitoring increases the chances of detecting changes in heart rhythm that may not occur during shorter tests, such as a simple electrocardiogram or 24-hour Holter monitor.

Paediatric Ambulatory Blood Pressure Monitoring (ABPM) is a test that automatically measures the child’s blood pressure over a 24-hour period, while they perform their daily activities and also during sleep.

This test is performed using a portable device connected to an arm cuff that inflates and takes regular measurements automatically, namely every 15 minutes during the day and every 20 minutes at night. This makes it possible to obtain a comprehensive record of fluctuations in blood pressure throughout the day and night.

ABPM provides a more thorough diagnosis of paediatric hypertension, helping:

• Confirm or rule out hypertension

• Assess suspected “White coat hypertension” (when high blood pressure readings only occur during medical visits)

• Monitor the effectiveness of treatment for hypertension

• Study the blood pressure pattern throughout the day and night