Introduction

• CPVT is a rare inheritable arrhythmogenic disorder

• Genetic analysis proved mutation of ryanodine receptor gene (RYR2) 

• It can be challenging to diagnose as patients have structurally normal hearts and a normal resting ECG

• However, adrenergic triggers such as physical or emotional stress may trigger a polymorphic ventricular tachycardia or a bidirectional ventricular tachycardia

• Patients with CPVT may present with syncope, cardiac arrest or sudden cardiac death

ECG characteristics

• patients typically have a normal resting ECG

• during exercise stress test atrial arrhythmias and/or bidirectional or polymorphic VT can occur and be used to establish the diagnosis

• bidirectional VT is a rare form of VT in which the axis changes in the frontal plane beat to beat, it can occur in CPVT, digitalis toxicity or herbal aconite poisoning

Management

• exercise restriction

• beta blockers - nadolol in particular is frequently used as a first line therapy

• flecainide may be added in symptomatic patients despite the use of beta blockers

• ICD implantation is currently recommended by guidelines as a secondary prevention in survivors of cardiac arrest (ICD should be programmed with long delays before shock delivery, because painful shocks can increase the sympathetic tone and trigger further arrhythmias, leading to a malignant cycle of ICD shocks and even death)

• ICD implantation in a primary prevention may be considered especially in patients symptomatic despite pharmacotherapy, however risks and benefits should be carefully considered 

• Left sympathetic denervation is less frequent alternative for treatment of recurrent malignant arrhythmias

ECG 1  Bidirectional ventricular tachycardia

ECG 2 Bidirectional couplets

References

1. Silvia G Priori, Carina Blomström-Lundqvist, Andrea Mazzanti et al. ESC Scientific Document Group, 2015 ESC Guidelines for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death: The Task Force for the Management of Patients with Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death of the European Society of Cardiology (ESC) Endorsed by: Association for European Paediatric and Congenital Cardiology (AEPC), European Heart Journal, Volume 36, Issue 41, 1 November 2015, Pages 2793–2867, https://doi.org/10.1093/eurheartj/ehv316
2. van der Werf, Christian, Krystien V Lieve, J Martijn Bos, Conor M Lane, Isabelle Denjoy, Ferran Roses-Noguer, Takeshi Aiba, et al. 2019. European Heart Journal 40 (35). https://doi.org/10.1093/eurheartj/ehz309.
3. Baltogiannis, Giannis G., Dimitrios N. Lysitsas, Giacomo di Giovanni, Giuseppe Ciconte, Juan Sieira, Giulio Conte, Theofilos M. Kolettis, Gian-Battista Chierchia, Carlo de Asmundis, and Pedro Brugada. 2019. “Cpvt: Arrhythmogenesis, Therapeutic Management, And Future Perspectives. A Brief Review Of The Literature”. Frontiers In Cardiovascular Medicine 6 (July). https://doi.org/10.3389/fcvm.2019.00092.
4. https://litfl.com/bidirectional-ventricular-tachycardia-bvt-ecg-library/

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