Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT)
An inherited rhythm disorder triggered by exercise or strong emotion
Quick Facts
- Type: Inherited heart rhythm disorder
- Triggers: Exercise, strong emotion, adrenaline
- Typical age: Children and young adults
- Key risk: Fainting and sudden cardiac arrest
Overview
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare, inherited disorder of the heart's electrical system. In people with CPVT, surges of adrenaline (catecholamines) during exercise or strong emotion can trigger a fast, chaotic rhythm from the ventricles, the heart's lower chambers. This can cause fainting and, in some cases, sudden cardiac arrest.
Unlike many heart conditions, the heart usually looks structurally normal on standard imaging, and the resting electrocardiogram is often normal too. CPVT typically first appears in childhood or adolescence, frequently as fainting during exertion. Because it carries a risk of life-threatening rhythms, early diagnosis and treatment are very important, and family members should also be evaluated.
Symptoms
Symptoms are usually brought on by physical activity or emotional stress rather than occurring at rest.
- Fainting (syncope) during or just after exercise or strong emotion
- Lightheadedness or dizziness with exertion
- Palpitations or a sensation of a racing, fluttering heart
- Seizure-like episodes caused by the brief loss of blood flow during an abnormal rhythm
Sudden cardiac arrest can be the first sign in some people. Any fainting that occurs during exercise or intense emotion should be evaluated urgently, because in CPVT it can signal a dangerous rhythm. Collapse with no pulse or no breathing is an emergency requiring CPR and emergency services.
Causes
CPVT is caused by inherited changes (mutations) in genes that control how calcium moves inside heart muscle cells. This calcium handling is essential for normal, coordinated heartbeats.
- Genetic mutations: The most common changes affect a calcium-release channel in heart cells; other related genes can also be involved.
- Adrenaline surges: During exercise or emotion, adrenaline causes abnormal calcium release in affected cells, triggering extra beats that can escalate into a dangerous rhythm.
The condition is usually inherited from a parent, though it can sometimes arise as a new mutation. Because it runs in families, relatives of an affected person should be screened.
Risk Factors
- A family history of CPVT, unexplained fainting, or sudden death at a young age
- Carrying a known CPVT-related gene mutation
- Young age, as symptoms often begin in childhood or adolescence
- Intense physical activity or competitive sports
- Situations that cause strong emotional stress or adrenaline surges
Diagnosis
Because resting tests are often normal, diagnosis usually requires provoking the heart under controlled conditions and considering the family history.
- Exercise stress test: A key test, as the abnormal rhythm typically appears as the heart rate rises with exertion.
- Holter or event monitoring: To capture rhythms during everyday activity and exercise.
- Genetic testing: Can identify the responsible mutation and guide screening of relatives.
- Family screening and history: Evaluating relatives, especially after unexplained fainting or sudden death in the family.
A resting electrocardiogram and echocardiogram are often normal, which is part of the diagnostic picture.
Treatment
Treatment aims to prevent dangerous rhythms and protect against cardiac arrest. It is directed by a heart rhythm specialist.
- Beta-blockers: The mainstay of treatment, taken regularly to blunt the effect of adrenaline on the heart.
- Additional medication: Other antiarrhythmic medicines, such as flecainide, may be added when beta-blockers alone are not enough.
- Activity restriction: Avoiding intense or competitive exercise and other strong triggers, as advised.
- Implantable defibrillator (ICD): Considered for people who have survived cardiac arrest or who continue to have dangerous rhythms despite medication.
- Specialized procedures: In selected severe cases, additional procedures may be considered.
Lifelong follow-up and consistent medication use are essential, and family members should be evaluated and treated if affected.
Prevention
CPVT cannot be prevented because it is inherited, but the risk of dangerous events can be greatly reduced:
- Take prescribed beta-blockers and other medicines consistently
- Avoid intense or competitive sports and known triggers as advised
- Attend regular follow-up with a heart rhythm specialist
- Have family members screened, since early diagnosis can be lifesaving
- Ensure people close to you know how to perform CPR and call emergency services
When to See a Doctor
Seek urgent medical evaluation for any fainting that occurs during exercise or strong emotion, or for unexplained fainting in a child or young adult, especially with a family history of sudden death. Call emergency services immediately if a person:
- Collapses and is unresponsive, not breathing, or has no pulse — begin CPR
- Has a seizure-like episode during exertion
- Has fainting followed by an irregular or very fast heartbeat
Frequently Asked Questions
What triggers a CPVT episode?
Episodes are typically triggered by surges of adrenaline during physical exercise or strong emotion. These surges cause abnormal calcium handling in heart cells, leading to a dangerous fast rhythm. Episodes rarely occur at rest, which is why exercise testing is central to diagnosis.
Is CPVT inherited?
Yes. CPVT is usually caused by an inherited gene change affecting calcium handling in heart cells, most often passed from a parent. Because it runs in families, relatives of an affected person should be evaluated, as early diagnosis can be lifesaving.
Can people with CPVT exercise?
People with CPVT are usually advised to avoid intense or competitive sports because exertion can trigger dangerous rhythms. Specific activity limits are set individually by a heart rhythm specialist based on the person's risk and treatment.
How is CPVT treated?
Treatment centers on beta-blocker medication taken consistently to blunt adrenaline's effect on the heart, sometimes with additional antiarrhythmic drugs. Avoiding triggers is important, and an implantable defibrillator may be recommended for those at highest risk.
Why is a resting ECG often normal in CPVT?
In CPVT the heart structure is usually normal and the resting electrocardiogram frequently appears normal because the abnormal rhythm only emerges with adrenaline. This is why an exercise stress test, which raises the heart rate, is often needed to reveal it.
References
- National Institutes of Health (NIH), Genetic and Rare Diseases Information Center. Catecholaminergic polymorphic ventricular tachycardia.
- MedlinePlus, U.S. National Library of Medicine. Catecholaminergic polymorphic ventricular tachycardia.
- American Heart Association (AHA). Inherited Arrhythmias.