By Steven Lome
Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT) is a rare genetic ventricular tachycardia which can result in sudden cardiac death and/or syncope in young individuals with structurally normal hearts. CPVT is triggered by catecholamine serges as can occur during exercise or emotional upset. The two genes linked to CPVT include the cardiac ryanodine receptor (autosomal dominant) and the calsequestrin 2 protein gene.
The diagnosis is made clinically when a young person with a structurally normal heart has syncope or cardiac arrest during exercise or emotional upset. The ECG would show a wide-complex QRS with a ventricular rate of at least 200 and frequently around 300 beats per minute (see ECG review of ventricular tachycardia). Genetic testing is also available.
Vigorous exercise should be strictly avoided. Beta-blockers can block the catecholaminergic surge that triggers the polymorphic VT. Implantable cardioverter defibrillators (ICDs) are recommended for symptomatic patients. Flecainide or verapamil have been used with success as well. Surgical left sympathetic denervation has been quite successful in small case series to treat refractory cases. This involves the surgical removal of the left stellate ganglion as well as the first 4-5 thoracic ganglia. This frequently results in a Horner's syndrome.