Why 'healthy' children may suffer sudden cardiac arrest

The deaths of two schoolchildren within days have brought an unsettling medical concern into focus: could children who appear perfectly healthy be living with undetected heart conditions that can trigger sudden cardiac death?

In the latest incident, a 13-year-old Class 8 student in Lucknow reportedly collapsed shortly after entering his classroom and died. His death came days after a nine-year-old girl died following a similar collapse at a school in Delhi.

The causes of the two deaths need to be established through medical investigations. But cardiologists say an underlying heart rhythm disorder, congenital abnormality or inherited heart condition can sometimes cause a child to collapse without any obvious warning.

These incidents also draw attention to a crucial difference not many understand – sudden cardiac arrest in children is not necessarily a conventional heart attack. It can result from an electrical malfunction in the heart that causes its rhythm to become dangerously abnormal, leaving it unable to pump blood effectively.

Some inherited heart conditions can remain undetected for years. A child may have no symptoms, participate in everyday activities and appear healthy, even while carrying an abnormality that increases the risk of a potentially fatal rhythm disturbance.

Clinician-scientist Dr Vinod Scaria points out that around one-fifth of sudden cardiac deaths in young people have a definite genetic cause. He identifies three important groups: cardiac channelopathies, cardiomyopathies and familial hypercholesterolaemia.

Channelopathies are disorders affecting the electrical channels that regulate the heartbeat. They can trigger dangerous rhythm disturbances, sometimes without any preceding symptoms.

Cardiomyopathies affect the heart muscle, causing it to become abnormally thick, enlarged or weakened and potentially interfering with its pumping function.

Familial hypercholesterolaemia is an inherited condition that causes extremely high LDL, or bad cholesterol, levels from childhood. If left undiagnosed and untreated, it can accelerate cardiovascular disease and increase the risk of premature heart complications.

Dr Anshul Kumar Jain, director of cardiology at CK Birla Hospital, Delhi, said an underlying rhythm disorder can cause the heart to beat abnormally fast, slow or irregularly. This can abruptly reduce blood supply to the brain and, in severe cases, lead to cardiac arrest.

"Certain congenital heart conditions, abnormalities of the heart muscle and previously undiagnosed electrical disorders can also increase this risk," he says.

Importantly, such events are not restricted to children playing sports or undertaking strenuous exercise. A dangerous rhythm disturbance can also occur during routine activities, including sitting in a classroom.

According to Dr Danish Hasan Kazmi, head of cardiology at Max Super Speciality Hospital in Lucknow, without immediate intervention, in case of a cardiac arrest, the brain and other vital organs are deprived of oxygen.UNDERSTANDING THE WARNING SIGNS

Although some inherited conditions produce no obvious symptoms, certain warning signs warrant medical attention. Unexplained fainting, particularly during physical activity, chest pain, palpitations, breathlessness and unusual fatigue should not be dismissed. A seizure-like episode can also sometimes accompany a cardiac event.

Family history is another important clue. Sudden unexplained deaths among young relatives, or a known inherited heart condition in the family, should prompt a medical assessment.

Dr Kazmi argues that schools should collect information about students' family medical histories, particularly instances of sudden unexplained death.

Children with concerning histories should be referred for cardiac evaluation, including an electrocardiogram (ECG), echocardiogram (ECHO) and paediatric cardiology consultation where indicated.

An ECG records the heart's electrical activity and can help identify certain rhythm abnormalities. An ECHO uses ultrasound to examine the heart's structure, muscles and pumping function. Depending on the suspected condition, doctors may recommend further tests such as Holter monitoring, exercise testing or genetic evaluation.

However, not every sudden collapse is cardiac.

As Dr Jain cautions, seizures, severe infections, metabolic disturbances and other medical emergencies can produce similar symptoms. A detailed medical assessment and, where appropriate, post-mortem findings are necessary before attributing a death to cardiac arrest.

There is also an immediate need to improve emergency preparedness in schools. Cardiac arrest requires rapid intervention. Staff trained in cardiopulmonary resuscitation (CPR) and access to an automated external defibrillator (AED) can improve the chances of survival. CPR helps maintain blood circulation, while an AED can deliver an electrical shock to restore an effective heart rhythm when indicated.

Also, experts say, the two deaths do not, by themselves, establish that sudden cardiac deaths among children are becoming more frequent. Nor does every child require routine ECG and ECHO screening.

Mass testing can produce false positives, while some inherited electrical disorders may not be detected through a single examination. The priority, therefore, should be to recognise warning symptoms, identify children with a concerning family history, ensure timely specialist assessment and make schools better equipped to respond when a child collapses.- Ends