Catecholaminergic Polymorphic Ventricular Tachycardia

What is CPVT?

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare condition. It causes an irregular heart rhythm that can be life-threatening. It often shows up in childhood, but it 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 two lower chambers are called ventricles. Normally, the signal to start your heartbeat comes from a group of specialized cells in the right upper heart called the sinoatrial (SA) node.

People with CPVT can develop a sudden, irregular, and fast heartbeat from the ventricles. This is called ventricular tachycardia (VT). With this condition, the heart beats so quickly that it doesn't have enough time to fill between beats. As a result, not enough blood gets pumped to the body. This can cause severe symptoms, such as loss of consciousness, collapse, and even death. If untreated, it is very dangerous.

What causes CPVT?

CPVT is caused by a gene defect (abnormal gene). Genes are part of your DNA, the material passed down from parents to children. It can be passed down through families and inherited in different ways (from either one or both parents). But the affected child could be the first case in the family.

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. There is a higher risk if there is a family history of fainting (syncope) or sudden death. If you or someone in your family has CPVT, you and all other family members should 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's 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 ventricular tachycardia (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 sign 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

• Event monitoring (you may need to wear a portable ECG for about 30 days)

• Implantable loop recorder (a heart rhythm recording device inserted over the heart underneath the skin for long-term monitoring)

• Echocardiogram, which is an ultrasound of the heart to examine blood flow in the heart and check the heart's function

• MRI of the heart, cardiac catheterization, or coronary angiography (if more information is needed)

• Genetic testing (in only some cases)

How is CPVT treated?

If someone is found to be in VT (ventricular tachycardia) or ventricular fibrillation, 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:

• Avoiding 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 or just below the armpit. It can detect a problem heart rhythm and provide treatment such as pulses to interrupt a fast heartbeat (called anti-tachycardia pacing, or ATP) and get it back to normal rhythm or a shock to help stop it. In some cases, 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.

Next steps

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 don't 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.