Can children or young adults get atrial fibrillation or SVT, and how is it treated? 

While heart rhythm disorders are often associated with older age, they can and do occur in children and young adults. In younger populations, the ‘cause’ of an arrhythmia is often very different from that of an older adult. While an older person’s arrhythmia might be due to decades of high blood pressure or wear and tear, a young person’s issue is frequently related to a ‘congenital’ (born-with) electrical quirk. Supraventricular Tachycardia (SVT) is the most common significant arrhythmia in the young, often caused by a tiny piece of ‘extra wiring’ that creates an electrical loop. Atrial Fibrillation, while much rarer in children, can also occur, particularly in those with underlying heart structures or inherited conditions. In the UK, paediatric cardiology focuses on providing treatments that allow children to remain active, social, and physically fit. This article explores how these conditions manifest in the young and the modern, effective ways they are managed. 

What We’ll Discuss in This Article 

• The clinical difference between SVT and Atrial Fibrillation in younger populations. 

• Why ‘extra wiring’ in the heart is the most common cause of SVT in children. 

• Recognising symptoms in infants and non-verbal children. 

• Diagnostic tools for young hearts: From ‘Patch’ monitors to ECGs. 

• Treatment options: Vagal manoeuvres, medication, and the ‘curative’ role of ablation. 

• The psychological impact of a heart rhythm diagnosis on young people. 

• Emergency safety guidance for sudden or severe cardiac symptoms. 

1. SVT in Children and Young Adults 

Supraventricular Tachycardia (SVT) is a ‘blanket term’ for several types of fast heart rhythms that start in the top chambers of the heart.³ 

• Wolff-Parkinson-White (WPW) Syndrome: This is a common cause in the young. It involves an extra electrical pathway (an ‘accessory pathway’) that acts like a shortcut, allowing the heart’s signal to race around in a circle. 

• AVNRT: This is the most common type of SVT in teenagers and young adults. It involves a tiny ‘re-entry’ loop within the heart’s natural gatekeeper (the AV node). 

• The Sensation: Younger patients often describe it as their heart ‘jumping’ or feeling like a ‘motor’ is running in their chest. It typically starts and stops suddenly, like a light switch. 

2. Atrial Fibrillation (AF) in the Young 

AF is rare in children but becomes more common in the late teens and twenties. 

• Triggers in Young Adults: In otherwise healthy young people, AF is often ‘paroxysmal’ (comes and goes) and can be triggered by binge drinking (‘Holiday Heart Syndrome’), extreme stress, or certain stimulants. 

• Underlying Causes: In children, AF is usually linked to congenital heart disease (issues with the heart’s structure from birth) or specific inherited ‘channelopathies’ that affect how heart cells handle minerals. 

3. Recognising Symptoms by Age 

A teenager can explain their palpitations, but a baby cannot. Parents and carers should look for these subtle signs: 

• In Infants: A baby with a fast heart rate (which can reach over 200 bpm during SVT) may become pale, unusually sleepy, irritable, or lose interest in feeding. Their breathing may seem faster or more ‘laboured’. 

• In Young Children: They might complain of a ‘tummy ache’ or say their ‘chest feels funny’. They may suddenly stop playing and sit down, appearing pale or breathless. 

• In Teens/Young Adults: Symptoms include sudden racing, chest ‘fluttering’, dizziness, and a feeling of anxiety or ‘doom’ during an episode. 

4. Diagnosis and Treatment Options 

In the UK, suspected arrhythmias in the young are referred to a specialist Paediatric Electrophysiologist. 

Diagnostic Tools 

Tests like the ECG and Echocardiogram (ultrasound) are standard. Because episodes are often brief, your doctor may use a ‘Patch’ or ‘Event’ monitor that the child wears for a week or more to ‘catch’ the rhythm when it happens. 

Treatment: The ‘Reset’ and the ‘Cure’ 

1. Vagal Manoeuvres: For SVT, children can be taught to ‘reset’ their heart by blowing into a blocked syringe or putting an ice-cold cloth on their face. These stimulate the vagus nerve to slow the heart. 

2. Medication: Beta-blockers (like Propranolol) are frequently used to prevent episodes. They are well-tolerated and allow most children to continue with sports and school. 

3. Catheter Ablation: This is often the preferred ‘cure’ for older children and young adults with recurrent SVT. A specialist uses a thin tube to ‘freeze’ or ‘burn’ the tiny piece of extra wiring. In the UK, this has a very high success rate (over 95%). 

Differentiation: SVT vs. AF in the Young 

This table highlights the key differences in how these two conditions typically present in younger patients. 

Feature	SVT in Children/Young Adults	AF in Children/Young Adults
Typical Cause	Extra ‘shortcut’ wiring (WPW/AVNRT).	Structural heart issues or lifestyle triggers.
Heart Rhythm	Very fast but regular (like a drum).	Fast and irregular (chaotic).
Frequency	Common paediatric arrhythmia.	Very rare in children.
Treatment Goal	Often ‘cured’ via ablation.	Managed via lifestyle and meds.
Exercise Impact	Can be a trigger; safe once treated.	Usually safe to continue light activity.

5. Living with an Arrhythmia as a Young Person 

A heart diagnosis can be frightening for a child and their family, but it should not be a barrier to a normal life. 

• School Support: In the UK, it is helpful to provide the school with an ‘Individual Healthcare Plan’. This ensures teachers know what to do if an episode happens and where the child’s medication is kept. 

• Sports and Activity: Most children with SVT or AF are encouraged to stay active.¹¹ Physical fitness actually helps regulate the heart’s nervous system.¹² Your cardiologist will provide specific guidance based on the ‘type’ of arrhythmia. 

• Psychological Wellbeing: It is normal for young people to feel anxious about their heart. Connecting with charities like ‘C-R-Y’ (Cardiac Risk in the Young) can provide peer support and reassurance. 

Conclusion 

While a heart rhythm disorder in a child or young adult is a significant medical event, the outlook is overwhelmingly positive. Most paediatric arrhythmias are caused by simple electrical ‘glitches’ that can be managed effectively with medication or permanently corrected with a procedure. By recognising the symptoms early, whether it’s a baby refusing to feed or a teenager feeling a sudden ‘thump’, parents can ensure their children receive the specialist care needed to protect their heart health. In the UK, the goal of paediatric cardiology is to ensure that a heart rhythm diagnosis remains a manageable part of a young person’s life, never standing in the way of their play, their education, or their future ambitions. 

If a child collapses, loses consciousness, or struggles to breathe, call 999 immediately. 

Authority Snapshot (E-E-A-T Block) 

This article was written by Dr. Stefan Petrov, a UK-trained physician with an MBBS and professional certifications in Advanced Cardiac Life Support (ACLS). Dr. Petrov has managed acute cardiac presentations across emergency departments and intensive care units, where he has treated patients of all ages for rhythm disturbances. This guide follows the standards of the NHS and the British Heart Foundation (BHF) to provide accurate, age-appropriate information on paediatric and young-adult cardiology.