Understanding Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT) (Child)
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare genetic condition. It causes a very serious fast abnormal heart rhythm or irregular heartbeat (arrhythmia).
How to say it
What happens during CPVT?
A heartbeat usually starts in the upper right chamber of the heart (right atrium). In people with CPVT, a sudden, fast heartbeat may start in the lower chambers of the heart (ventricles). This causes an abnormally fast heart rhythm. This is called ventricular tachycardia (VT). With CPVT, the heart beats so fast it doesn't have enough time to fill between beats. As a result, less blood is pumped to the body and brain. This causes symptoms like dizziness, lightheadedness, heart beating harder or faster, fainting (syncope), and other symptoms. If untreated, sudden cardiac death may occur.
What causes CPVT?
CPVT is a genetic condition. It is caused by an abnormal change in a gene (mutation). It can be passed down through families and inherited from either 1 or both parents). But a child could be the first case in the family. This is called a “de novo" mutation. There is a higher risk if there is a family history of syncope or sudden death. If you or any family member has have CPVT, all other family members should have genetic testing and heart testing. These tests can diagnose CPVT in other family members.
What are the symptoms of CPVT?
Symptoms of CPVT usually occur at a young age. But they sometimes don't happen until later in life. Your child may have fainting (syncope), or near fainting. This happens most often during exercise, excitement, or when feeling strong emotions. Your child may also have symptoms such as:
The episode of ventricular tachycardia may go away on its own. Or it may turn into a very irregular and very fast heartbeat. This is called ventricular fibrillation (VF). This is a life-threatening heartbeat that can cause the heart to stop (cardiac arrest) and death. The person loses consciousness and stops breathing. In some cases, an episode of CPVT with cardiac arrest may be the first time the condition is found.
How is CPVT diagnosed?
CPVT is often diagnosed at a young age. This usually happens when a child has fainted from physical or emotional stress. The healthcare provider will ask about your child’s health history and symptoms. He or she will also ask about your family health history. Your child will have a physical exam. Your child may need to see a heart doctor (cardiologist). He or she may advise tests such as:
Electrocardiography (ECG). This is to check your child’s heartbeat and rhythm. Resting ECG results are usually normal in people with CPVT.
Exercise stress testing. This is to check how the heart works when stressed, such as during exercise. It also looks at the heart rhythm during exercise.
Medicine challenge. A medicine is given that makes the heart work harder. This simulates exercise. This may be done if your child can’t exercise.
Event monitoring. Your child wears a portable ECG monitor for about 30 days. This device records heart activity.
Holter monitoring. Your child wears a portable ECG monitor for 1 or more days.
Echocardiography. This is an ultrasound of the heart. It is done to check for problems in the heart's structure and function. It shows problems in the heart's muscle, wall motion, and valves.
MRI of the heart. This test gives a more detailed view of the structures in and around the heart.
Heart catheterization. This is also called an electrophysiology (EP) study. This test is done to study the physical and electrical workings of the heart.
Genetic testing. This is to check for gene defects.
What is the treatment for CPVT?
CPVT is most often treated with medicines called beta blockers. Two examples of these are nadolol and propranolol. Your child may also be given a medicine called Flecainide. This helps control the heart rhythm. Some children may need an implantable cardioverter defibrillator (ICD). This is a small device put under the skin of the chest. It has wires that lead to the heart. The device can reset the heart rhythm when needed.