Catecholaminergic Polymorphic Ventricular Tachycardia
What is CPVT?
Catecholaminergic polymorphic ventricular tachycardia, or CPVT, is a rare condition. It causes an irregular heart rhythm that can be life threatening. It often shows up in childhood, but can show up later in life. The first sign is often fainting or near fainting during exercise or strong emotion.
Your heart has 4 chambers. The 2 upper chambers are called atria. The 2 lower chambers are called ventricles. Normally, the signal to start your heartbeat comes from a group of specialized cells in the heart called the sinoatrial (SA) node. This node is in the upper right chamber of the heart (right atrium).
People with CPVT can develop a sudden, irregular, and rapid heart rhythm from the ventricles. This is called ventricular tachycardia (VT). With this condition, the heart beats so quickly that it does not have enough time to fill between beats. As a result, not enough blood gets pumped to the body. This abnormal heart rhythm can cause severe symptoms, such as loss of consciousness, collapse, and even death. If untreated, it is very dangerous.
What causes CPVT?
In most cases, CPVT results from an abnormality in one of a few different genes that you get (inherit) from your parents. Genes are part of your DNA, the material passed down from parents to children. Having the abnormal gene leads to the risk of VT. Although CPVT is typically inherited, it can also occur "de novo" which means that it was not inherited.
In some cases, CPVT is autosomal dominant. This means you need an abnormal gene from only one of your parents to have it. In other cases, CPVT is autosomal recessive. This means you need an abnormal gene from both of your parents to get the disease.
Researchers are still trying to understand what other factors may increase the chances of having the disease as well as having symptoms of it. Stress and exercise can trigger episodes. Caffeine may make the episodes worse. Certain medicines, such as catecholamines, can also make it worse.
Who is at risk for CPVT?
Having a relative with CPVT puts you at risk for the disease. If someone in your family has CPVT, you may need to see a healthcare provider to get checked. You may need a genetic test.
There isn’t anything you can do to decrease your risk of CPVT, since it is likely inherited. But you can do certain things to reduce the chance of having episodes. This includes things such as avoiding triggers and taking certain medicines. Your healthcare provider may also recommend an implantable cardioverter defibrillator (ICD). An ICD can detect a problem heart rhythm and give a shock to help stop it.
What are the symptoms of CPVT?
The symptoms typically start with VT. You may faint or feel lightheaded. You may have an unpleasant awareness of your heartbeat. These symptoms tend to occur when you are physically active. It may also happen when you feel emotionally stressed. The VT may cause you to lose consciousness. This is commonly the first sign of the disease. Sometimes the VT goes away, and symptoms stop.
Other times, VT can turn into ventricular fibrillation (VF). This is more dangerous. It causes the ventricles quiver. They are unable to pump blood. This sudden loss of heart function leads to sudden cardiac arrest. A person stops breathing and becomes unresponsive. Unfortunately, sudden cardiac arrest is sometimes the first manifestation of CPVT. Sudden cardiac arrest can lead to sudden cardiac death.
How is CPVT diagnosed?
Diagnosis of CPVT can be challenging. Your healthcare provider will ask about your medical history. They will give you a physical exam. You may also have tests such as:
- Electrocardiogram (ECG), to analyze the heart rhythm (usually normal at rest)
- Exercise stress test with ECG (the most important test to diagnose CPVT; most people with CPVT have VT when their heart rate is high)
- Continuous portable ECG monitoring, to further analyze heart rhythms
- Echocardiogram, to examine blood flow in the heart
- MRI of the heart, cardiac catheterization, or coronary angiography (if more information is needed)
- Genetic testing (only in some cases)
How is CPVT treated?
In the acute setting, if someone is found to be in VT (ventricular tachycardia), treatment typically involves electrical cardioversion/defibrillation (shock) to return the heart rhythm back to normal. For long term management, healthcare providers use a variety of treatments for CPVT such as:
- Avoidance of competitive sports and strenuous exercise
- Medicines to prevent irregular heartbeats, such as beta-blockers and sometimes calcium channel blockers
- Medicines to help prevent abnormal heart rhythms
Some people with CPVT including those who have had a prior cardiac arrest or fainting may also need an implantable cardioverter defibrillator, or ICD. An ICD is a small device put under the skin near the chest. It can detect a problem heart rhythm and provide treatment such as pulses to interrupt a fast heart beat (called anti-tachycardia pacing, or ATP) and get it back to normal rhythm or a shock to help stop it. In some circumstances, a catheter ablation may be recommended.
If you still have symptoms, your healthcare provider may advise sympathetic denervation surgery. This is a surgery to remove the nerves that can signal the heart to beat faster.
If you have VT, you may need an electrical shock to your heart. This helps restore a normal rhythm. VT can also lead to VF. This is a medical emergency and needs treatment right away. Treatment includes a shock to the heart to help restore normal heart rhythm.
How do I manage CPVT?
Your healthcare provider may give you more instructions about how to manage your CPVT, such as:
- Talking with your healthcare provider about what kind of exercise is safe for you.
- Monitoring your symptoms carefully. Make sure you see a healthcare provider regularly, even if you don’t have any symptoms.
- Making sure all your healthcare providers know about your CPVT.
- Limiting caffeine intake.
When should I call my healthcare provider?
See a healthcare provider right away if your symptoms get worse or happen more often.
Key points about CPVT
CPVT is a rare genetic condition. It can cause VT. This is an abnormal heart rhythm. This rhythm sometimes goes away with minimal symptoms. Sometimes it turns into VF. This causes cardiac arrest.
Most people with CPVT need treatment with medicine. Some people need an implantable cardioverter defibrillator. Others may need a procedure called an ablation. Other members of your family may need to be checked and watched for CPVT.
- Follow your healthcare provider’s instructions carefully. This includes any instructions on exercise. Take all your medicines as prescribed.
- See your healthcare provider for regular check-ups. This is important even if you don’t have any symptoms.
- Tell your healthcare provider if your symptoms get worse.
Tips to help you get the most from a visit to your healthcare provider:
- Know the reason for your visit and what you want to happen.
- Before your visit, write down questions you want answered.
- Bring someone with you to help you ask questions and remember what your provider tells you.
- At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.
- Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are.
- Ask if your condition can be treated in other ways.
- Know why a test or procedure is recommended and what the results could mean.
- Know what to expect if you do not take the medicine or have the test or procedure.
- If you have a follow-up appointment, write down the date, time, and purpose for that visit.
- Know how you can contact your provider if you have questions.