Catecholaminergic polymorphic ventricular tachycardia associated with sinus node dysfunction and junctional rhythm: Case report and literature review

We report the case of a 38-year-old woman with history of syncope and polymorphic ventricular tachycardia; tachycardia was inducible at exercise stress test, not at electrophysiologic study. Phases of QT prolongation were found at ambulatory electrocardiogram monitoring. The woman came to our attention for periodic control of implantable loop recorder. Rest electrocardiogram at admission unexpectedly showed sinus bradycardia, junctional rhythm, and ventricular premature beats. Furthermore, loop recorder control revealed a short run of bidirectional tachycardia, not associated with syncope. Final diagnosis was catecholaminergic polymorphic ventricular tachycardia, and the patient was implanted with an ICD. We therefore report an unusual case of bidirectional ventricular tachycardia associated with sinus node dysfunction and junctional escape rhythm. We hypothesize that a diffuse dysfunction of cardiac conduction system, presumably based on diffuse disorder of calcium handling, may be responsible for both sinus node failure and ventricular tachycardia.