CPVT (catecholaminergic polymorphic ventricular tachycardia) factsheet
Introduction
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare heart rhythm disorder that causes arrhythmias in the ventricles, the lower chambers of the heart. Arrhythmias are fast, irregular heart rhythms.
Arrhythmias can happen when stress hormones are released into the body. Stress hormones increase heart rate and blood pressure when your child is physically or emotionally stressed. This helps their body to get more energy and be more alert.
When a child has CPVT, the stress hormones cause their heart to beat very fast and in an abnormal pattern. This is dangerous because it can limit or stop the flow of blood to the rest of the body.
Signs and symptoms
Children with CPVT will usually have symptoms when they are having strong emotions like stress and excitement or doing physical activity.
They can include:
- feeling faint or dizzy more than usual
- losing consciousness or passing out
- having hard, fast heartbeats
- seizures or fits.
Diagnosis
CPVT can be difficult to diagnose because there are not usually any differences in how the heart looks.
Your local doctor will refer your child to a heart specialist called a cardiologist for testing and diagnosis.
The cardiologist will take a medical and family history for your child and will order tests like:
- an electrocardiogram (ECG) to test the electrical activity of the heart while your child is resting
- an exercise stress test where your child has an ECG done while they are running on a treadmill
- an adrenaline challenge where the stress hormone adrenaline is given while the heart is being monitored
- genetic testing to see if CPVT runs in your family.
Treatment
Medications
CPVT is usually treated with medications called beta-blockers. Beta-blockers stop stress hormones like adrenaline from making the heart beat faster.
Beta-blockers used to manage CPVT include:
- propranolol
- atenolol
- nadolol.
Your child’s doctor will talk to you about different medications and the best one to use.
Lifestyle changes
Lifestyle changes can help lower stress levels for your child. For most children, this means avoiding high-energy activities like competitive sports and swimming.
Implantable cardioverter defibrillator (ICD)
Some children may need an operation to implant a device called an implantable cardioverter defibrillator (ICD). This device sits under your child's skin, underneath either the left collarbone or the ribcage.
The ICD uses electrical pulses to:
- monitor the heart
- keep the heart beating at a normal rate
- get the heart beating normally again if it senses a dangerous rhythm.
An ICD may be needed to manage CPVT if:
- beta-blockers have not worked well
- your child has already had a serious heart episode.
Automatic External Defibrillator (AED)
An AED is a portable device that can check your child's heartbeat and provide an electric shock to restore a normal rhythm. It has sticky pads for the chest and reads out clear emergency instructions.
AEDs are commonly found in public places like:
- shopping centres
- airports
- workplaces
- parks
- community centres.
Speak to your child’s cardiologist about whether it is safe to use this device in an emergency.
Management
CPVT and genetic testing
CPVT can be a genetic condition. This means it can be passed from parents to children.
If your child has the gene that causes CPVT, they may pass it down to any children they might have in the future.
Your child’s cardiologist will offer genetic testing to see if other family members have the gene.
Not all siblings of children with CPVT will inherit the gene or have any heart problems.
Resources and more information
The Heart Centre for Children (at Westmead) is home to The Inherited Arrhythmia Clinic (IAC), a dedicated centre supporting children diagnosed with CPVT and their families. They offer a comprehensive range of services for families with this diagnosis and other arrhythmias.