This acute situation is exemplified by the condition of catecholaminergic polymorphic ventricular tachycardia (CPVT), associated with cardiac ryanodine receptor (RyR2) mutations that result in episodic atrial arrhythmias, including sinus bradycardia, junctional rhythms and AF, in addition to ventricular tachyarrhythmias. Here, RYR2 is linked to catecholaminergic polymorphic ventricular tachycardia.