Heart arrhythmia in children is a condition where the heart beats too fast, too slow, or in an irregular pattern. It can range from completely harmless to potentially serious. As a parent, knowing the signs and understanding what to expect can help you act quickly if something seems wrong. This article explains what causes arrhythmias in children, how doctors diagnose them, and what treatment options are available to Canadian families.
What Is Heart Arrhythmia in Children?
A heart arrhythmia is any change to the heart’s normal, steady rhythm. A child’s heart may beat too fast, too slow, or skip beats in an uneven pattern. This can happen because of an underlying heart condition or because of something outside the heart, like a fever or an infection.
Children’s hearts are naturally more sensitive than adult hearts. Even everyday activities like running, crying, or playing hard can sometimes trigger a brief arrhythmia. However, most of these episodes are harmless and pass on their own.
Some arrhythmias are more serious. For example, tachycardia (a very fast heart rate) or bradycardia (a very slow heart rate) can reduce the heart’s ability to pump blood effectively. This affects every organ in the body, so it’s important not to ignore symptoms that keep coming back.
How the Heart’s Electrical System Works
To understand arrhythmias, it helps to know how the heart normally works. The heart runs on a precise electrical system. A small electrical signal travels through a network of pathways and tells the heart muscles when to contract.
The signal starts in a structure called the sinoatrial (SA) node, located in the upper right chamber of the heart. From there, it travels to the left atrium and then down to the atrioventricular (AV) node. The AV node passes the signal to the lower chambers, called the ventricles, which then contract and pump blood to the lungs and the rest of the body.
When this circuit works properly, the heartbeat is steady and regular. However, any disruption to this pathway can cause the rhythm to change. That disruption is what we call an arrhythmia.
Types of Heart Arrhythmia in Children
There are several types of heart arrhythmia in children. Doctors group them into three main categories: supraventricular arrhythmias, ventricular arrhythmias, and bradyarrhythmias.
Supraventricular (Atrial) Arrhythmias
These arrhythmias start in the upper chambers of the heart, called the atria. They include:
Premature atrial contractions: Extra beats that start in the atria earlier than expected. They are usually harmless.
Supraventricular tachycardia (SVT): A fast but regular heartbeat that originates in the atria. SVT is one of the most common arrhythmias seen in children.
Paroxysmal supraventricular tachycardia: A sudden episode of rapid heartbeat caused by an electrical signal looping through the AV node.
Atrial fibrillation: Multiple electrical signals fire from different spots in the atria at once, creating a very irregular rhythm.
Atrial flutter: A rapid but more organised rhythm caused by multiple looping circuits in the atria.
Wolff-Parkinson-White (WPW) syndrome: A condition present from birth where an extra electrical pathway causes the signal to reach the ventricles too quickly.
Ventricular Arrhythmias
These arrhythmias begin in the lower chambers of the heart. They tend to be more serious than supraventricular types. They include:
Premature ventricular contractions (PVCs): Early beats originating in the ventricles. They are more concerning than premature atrial contractions.
Ventricular tachycardia: A fast and irregular rhythm that starts in the ventricles. This is a potentially life-threatening arrhythmia that requires urgent medical attention.
Ventricular fibrillation: A chaotic, disorganised rhythm in the ventricles. This is a medical emergency and can be fatal without immediate treatment.
Bradyarrhythmias
Bradyarrhythmias are arrhythmias where the heart beats too slowly. They can result from a problem with the SA node or from a heart block, where the electrical signal between the atria and ventricles is partially or completely blocked. In children, these can sometimes be linked to congenital heart conditions.
Common Causes of Arrhythmia in Children
Heart arrhythmias in children can come from inside the heart or from factors outside it. Understanding the cause helps doctors choose the right treatment approach.
Internal (cardiac) causes include:
Congenital heart defects (heart problems present from birth)
Cardiomyopathy (disease of the heart muscle)
Previous heart surgery
Inherited electrical abnormalities, such as WPW syndrome
External causes can trigger arrhythmias even in children with otherwise healthy hearts. These include:
Infections and fever
Electrolyte imbalances (low potassium or magnesium levels)
Certain medications
Stimulants, including high amounts of caffeine
Emotional stress or intense physical activity
In many cases, once the external cause is treated, the arrhythmia resolves on its own. Therefore, your child’s doctor will often look for these triggers first before moving on to more complex investigations.
Signs and Symptoms to Watch For
Recognising the symptoms of heart arrhythmia in children depends heavily on the child’s age. Older children can describe what they feel. Younger children and infants can only show signs that something is wrong, so parents need to pay close attention.
Common symptoms in older children and teenagers include:
Palpitations (a fluttering or pounding feeling in the chest)
Dizziness or light-headedness
Fainting or near-fainting (called syncope)
Chest pain or discomfort
Shortness of breath
Unusual fatigue or weakness
Sweating without a clear cause
In infants and very young children, signs may include:
Pale or grey skin colour
Feeding difficulties
Unusual irritability
Rapid breathing
A weak or racing pulse
Reduced alertness or limpness
Furthermore, if your child loses consciousness or you cannot wake them, call 911 immediately. Do not wait to see if it passes on its own.
How Doctors Diagnose Arrhythmia in Children
Diagnosing a pediatric heart arrhythmia starts with a careful conversation. Your child’s doctor will ask detailed questions about symptoms, when they happen, and how long they last. It helps to write down observations before the appointment so you don’t forget anything.
After taking a history, the doctor will do a physical examination. They will listen to the heart and look for any visible signs of a problem. Blood tests may also be ordered to rule out external causes like infection or electrolyte imbalances.
Electrocardiogram (ECG)
An electrocardiogram (ECG) is the most important test for diagnosing arrhythmias. It records the heart’s electrical activity quickly and painlessly. Most family doctors and paediatric clinics across Canada can perform a basic ECG. In some cases, a referral to a paediatric cardiologist may be needed.
Holter Monitor
If the ECG looks normal but symptoms continue, the doctor may recommend a Holter monitor. This is a portable device the child wears for 24 to 48 hours. It records a continuous ECG and can catch arrhythmias that only happen occasionally or during sleep.
Other Tests
In addition, depending on the suspected cause, further tests may include:
An echocardiogram (ultrasound of the heart) to check for structural problems
An exercise stress test to see how the heart behaves during physical activity
Electrophysiology studies, which map the heart’s electrical pathways in detail
These tests are typically done at a paediatric heart centre. In Canada, referrals to paediatric cardiology are covered under provincial health plans, though wait times vary by province.
Treatment Options for Heart Arrhythmia in Children
The good news is that many arrhythmias in children do not require any treatment at all. When treatment is needed, the approach depends on the type of arrhythmia, its cause, and how much it affects your child’s daily life.
Treating the Underlying Cause
When an external factor is responsible, treating that factor often resolves the arrhythmia. For example, fever-related arrhythmias improve with fever-reducing medication. Arrhythmias caused by electrolyte imbalances improve when those levels are corrected.
Medications
Some children need anti-arrhythmic medications to control their heart rhythm. These are prescribed and carefully monitored by a paediatric cardiologist. The type of medication depends on the specific arrhythmia. Regular follow-up appointments are essential to make sure the medication is working safely.
Vagal Manoeuvres
For certain types of supraventricular tachycardia, doctors may teach children and parents simple physical techniques called vagal manoeuvres. These stimulate the vagus nerve and can slow the heart rate during an episode. One example is the Valsalva manoeuvre, where the child bears down as if having a bowel movement.
Catheter Ablation
For arrhythmias that keep coming back and don’t respond well to medication, a procedure called catheter ablation may be recommended. A thin, flexible tube is guided to the heart to destroy the small area of tissue causing the abnormal signal. This procedure has a high success rate in children and is considered a long-term solution for conditions like WPW syndrome and SVT.
Pacemakers and Implantable Devices
Children with bradyarrhythmias or life-threatening ventricular arrhythmias may need a pacemaker or an implantable cardioverter-defibrillator (ICD). These devices are implanted under the skin and automatically correct dangerous rhythms. They are used when other treatments are not sufficient.
For more information on heart conditions in children, visit Health Canada’s official health resources. You can also learn more from the Mayo Clinic’s guide to heart arrhythmia or explore additional research through the World Health Organization’s cardiovascular disease resources.
When to See a Doctor
If you notice any of the symptoms listed above in your child, it’s always a good idea to speak with your family doctor first. They can perform an initial assessment and refer your child to a paediatric cardiologist if needed. Most provincial health plans in Canada cover these referrals at no direct cost to families.
If you don’t have a family doctor, a walk-in clinic can be a helpful starting point. Tell the clinic staff about your child’s symptoms clearly. Bring notes about when the symptoms occur, how long they last, and whether anything seems to trigger them.
However, some situations require emergency care right away. Call 911 or go to your nearest emergency department immediately if your child:
Faints or loses consciousness
Has severe chest pain
Has difficulty breathing that does not improve
Has a very rapid or very slow pulse and appears unwell
Becomes limp, pale, or unresponsive
As always, consult your child’s doctor before drawing any conclusions about symptoms. Only a qualified healthcare provider can properly diagnose and treat a heart condition.
Frequently Asked Questions
Can heart arrhythmia in children go away on its own?
Yes, many cases of heart arrhythmia in children are harmless and resolve without any treatment. For example, arrhythmias triggered by fever, infection, or stress often disappear once the underlying cause is treated. However, always have a doctor evaluate recurring or concerning symptoms.
What does a heart arrhythmia feel like for a child?
Older children often describe it as a fluttering, pounding, or racing feeling in the chest. Some children also feel dizzy, short of breath, or unusually tired during an episode. Younger children may simply seem irritable, pale, or unwilling to feed.
Is pediatric heart arrhythmia hereditary?
Some types of heart arrhythmia in children do have a genetic component. Conditions like Wolff-Parkinson-White syndrome and long QT syndrome can run in families. If there is a family history of arrhythmias or sudden cardiac events, tell your child’s doctor so they can assess the risk.
