Bidirectional Ventricular Tachycardia (BVT)

• In the example below, you can see the QRS axis shifts 180 degrees from left to right with each alternate beat
• Another possible pattern is alternating left and right bundle-branch block (see Figure 2 in the paper by Smith et al)

Causes

• This rhythm is most commonly associated with severe digoxin toxicity
• It may be the presenting rhythm in patients with familial catecholaminergic polymorphic ventricular tachycardia (CPVT)
• BVT has also been reported with herbal aconite poisoning

ECG Examples

Example 1

• Multifocal ectopy and bidirectional VT secondary to digoxin poisoning

Example 2

• Bidirectional VT due to digoxin toxicity

Example 3

Exercise stress test in a patient with CPVT:

• Progressively worsening ventricular arrhythmias are observed during exercise
• Typical bidirectional VT develops after 1 minute of exercise with a sinus heart rate of approximately 120 beats per minute
• Arrhythmias rapidly recede during recovery

Related Topics

• Digoxin toxicity

References

• Menduiña MJ, Candel JM, Alaminos P, Gómez FJ, Vílchez J. Bidirectional ventricular tachycardia due to digitalis poisoning. Rev Esp Cardiol. 2005 Aug;58(8):991-3.
• Smith SW, Shah RR, Hunt JL, Herzog CA. Bidirectional ventricular tachycardia resulting from herbal aconite poisoning. Ann Emerg Med. 2005 Jan;45(1):100-1
• Richter S, Brugada P. Bidirectional ventricular tachycardia. J Am Coll Cardiol. 2009 Sep 22;54(13):1189.
• Napolitano C, Priori SG, Bloise R. Catecholaminergic Polymorphic Ventricular Tachycardia. 2004 Oct 14 [updated 2009 Jul 7]. In: Pagon RA, Bird TC, Dolan CR, Stephens K, editors. GeneReviews [Internet]. Seattle (WA): University of Washington, Seattle (1993)

Advanced Reading

Online

• Wiesbauer F, Kühn P. ECG Mastery: Yellow Belt online course. Understand ECG basics. Medmastery
• Wiesbauer F, Kühn P. ECG Mastery: Blue Belt online course: Become an ECG expert. Medmastery
• Kühn P, Houghton A. ECG Mastery: Black Belt Workshop. Advanced ECG interpretation. Medmastery
• Rawshani A. Clinical ECG Interpretation ECG Waves
• Smith SW. Dr Smith’s ECG blog.

Textbooks

• Zimmerman FH. ECG Core Curriculum. 2023
• Mattu A, Berberian J, Brady WJ. Emergency ECGs: Case-Based Review and Interpretations, 2022
• Straus DG, Schocken DD. Marriott’s Practical Electrocardiography 13e, 2021
• Brady WJ, Lipinski MJ et al. Electrocardiogram in Clinical Medicine. 1e, 2020
• Mattu A, Tabas JA, Brady WJ. Electrocardiography in Emergency, Acute, and Critical Care. 2e, 2019
• Hampton J, Adlam D. The ECG Made Practical 7e, 2019
• Kühn P, Lang C, Wiesbauer F. ECG Mastery: The Simplest Way to Learn the ECG. 2015
• Grauer K. ECG Pocket Brain (Expanded) 6e, 2014
• Surawicz B, Knilans T. Chou’s Electrocardiography in Clinical Practice: Adult and Pediatric 6e, 2008
• Chan TC. ECG in Emergency Medicine and Acute Care 1e, 2004

LITFL Further Reading

• ECG Library Basics – Waves, Intervals, Segments and Clinical Interpretation
• ECG A to Z by diagnosis – ECG interpretation in clinical context
• ECG Exigency and Cardiovascular Curveball – ECG Clinical Cases
• 100 ECG Quiz – Self-assessment tool for examination practice
• ECG Reference SITES and BOOKS – the best of the rest