What is CPVT?
CPVT is an abnormal heart rhythm (arrhythmia) caused by the body's "fight or flight" response that happens in times of stress or physical exercise/exertion. At these times, the body releases hormones called “catecholamines”, more commonly known as adrenaline, noradrenaline, and dopamine.
In most patients with CPVT, the release of catecholamines, such as with physical exertion during competitive sports, causes an abnormal release of calcium by the heart's cells and can lead to an irregular fast rhythm in the ventricles (bottom chambers of the heart), called polymorphic ventricular tachycardia. This rhythm can result in low blood flow out to the body, including to the heart tissue itself, which can then lead to syncope (fainting) or even sudden death. Patients with CPVT can also have irregular heart rhythms in the atria (the top chambers of the heart). The resting electrocardiogram (ECG) in a person with CPVT is often normal. Signs of this disease are usually only visible with stress or physical activity when there is an increase in catecholamines.
People with CPVT often have episodes of fast heart rates (ventricular tachycardia) that might be combined with periods of normal heart rates. The longer and faster the ventricular tachycardia, the more dangerous the episode.