RYR2 and ventricular tachycardia: In particular, the absence of further enhancement of the Ca2+ release by adrenergic stimulation, as observed for CPVT RyR2 mutations, is an interesting topic to elucidate in order to gain an insight into the underlying mechanisms of scTdP RyR2 variants and this type of ventricular tachycardia originating from Purkinje fibres at rest.