CPVT is the perfect occult killer of young people. The first symptom can be sudden cardiac death, and warning symptoms can be easily misinterpreted. Misdiagnosis of CPVT as epilepsy is common, and near drownings overlooked. Genetic investigation of sudden death of teenagers by screening the RyR2 gene reveals that CPVT is as common as a cause of death as long QT syndrome. Yet it is much rarer that Long QT, declaring that it tends to be a highly malignant condition.
Diagnosis is made clinically by a classic history of sudden unheralded collapse triggered by exercise, particularly swimming, or startle. The resting ECG and echocardiogram are typically normal, though uncommonly there may be a cardiomyopathy or mitral valve prolapse. The family history may be positive for young sudden death, but at least 30% occur denovo, with neither parent affected.
A sprint exercise test typically reveals bidirectional VT, or other polymorphic VT. Management begins with beta blockade, but mortality remains high. Flecainide is a useful adjunct as well as and cardiac sympathectomy. Defibrillator pacemakers whilst sometimes essential can bring significant risks of their own.