Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited disease that causes cardiac arrhythmias due to an electrical instability in the hearts pacing system described above. There is no apparent physical problem with the heart muscle.
The origin of the CPVT arrhythmia is considered to be in the right ventricle where QRS morphology (ECG pattern) shows a left bundle branch block pattern, and in the left ventricle when a right bundle branch block pattern is present. The electrical signal that causes the onset of CPVT is mostly single or double origin and usually originates from the right ventricular outflow tract instead of at the sinus node. The following beat tends to originate from within the left ventricle. CPVT is usually characterised by bi-directional polymorphic VT that can be induced during exercise or catecholamine infusion and other events provoking sympathetic nervous system activation. A third of patients suffering from CPVT have a family history of premature sudden death or stress related syncope.
Exercise-induced polymorphic ventricular arrhythmias, syncope occurring during physical activity or acute emotion. Without treatment a patient with CPVT is prone to ventricular tachycardia (VT), this may self terminate or degenerate to ventricular fibrillation which can in some cases cause sudden death.