Unusual clinical presentation in a family with catecholaminergic polymorphic ventricular tachycardia due to a G14876A ryanodine receptor gene mutation.

A family was identified, of whom which 11 members were carriers of the G14876A ryanodine 2 receptor mutation. All but 1 were symptomatic at the time of the study. Exercise testing showed bidirectional or polymorphic arrhythmias in 4 patients, whereas in 5 patients, it showed monomorphic or rare minor polymorphic ventricular arrhythmias. Two young patients died suddenly at rest while asleep. This study demonstrates that arrhythmias occurring during exercise stress testing in patients affected by catecholaminergic polymorphic ventricular tachycardia (CPVT) could be minor even in very symptomatic patients. The diagnosis of CPVT must be considered in these patients with a familial history of typical CPVT.