Bidirectional Ventricular Tachycardia

Bidirectional ventricular tachycardia


  • Bidirectional ventricular tachycardia (BVT) is a rare ventricular dysrhythmia characterised by a beat-to-beat alternation of the frontal QRS axis.
  • In the example above, 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).



Multifocal ectopy and bidirectional VT secondary to digoxin poisoning

Another example of bidirectional VT due to digoxin toxicity

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

Further Reading

Author Credits


  • 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. Spanish [PMID: 16053836] [Full text – English]
  • Murray L, Daly F, McCoubrie D, Soderstrom J, Pascu O, Armstrong J, Cadogan M. Toxicology Handbook, Second Edition. Churchill Livingstone (2010).
  • 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) [PMID: 20301466]
  • Richter S, Brugada P. Bidirectional ventricular tachycardia. J Am Coll Cardiol. 2009 Sep 22;54(13):1189. [Full text].
  • 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 [Full text]
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