Myth: Ventricular Tachycardia must have precordial concordance
When differentiating a regular, wide-complex tachycardia some will look for precordial concordance to rule-in, or more importantly to rule-out ventricular tachycardia.
The absence of precordial concordance is not a reliable method of ruling out ventricular tachycardia:
Although the specificity of concordance for VT is high (>90%), the sensitivity is low (~20%)1.It is generally thought that positive concordance indicates a posteriobasal left ventricular origin and negative concordance indicates an anterioapical left ventricular origin. However, in the case of positive concordance, SVT with a left-posterior accessory pathway is a known cause.
Until recently, negative concordance has been thought to be "virtually diagnostic" of ventricular tachycardia2. Multiple case reports have shown that certain configurations of accessory pathways can also cause negative concordance3,4,5.
The key takeaway is while this criteria is a useful tool to rule-in ventricular tachycardia (i.e. high specificity), it is not a useful tool to rule-out ventricular tachycardia (i.e. low sensitivity).
|Ventricular tachycardia without precordial concordance6.|
|Ventricular tachycardia without precordial concordance. (c) 2011 EMS 12-Lead Blog.|
|WPW and Atrial flutter with positive concordance7.|
- Pellegrini CN, Scheinman MM. Clinical management of ventricular tachycardia. Curr Probl Cardiol. 2010; 35(9):453-504. [PubMed]
- Goldberger ZD, Rho RW, Page RL. Approach to the Diagnosis and Initial Management of the Stable Adult Patient With a Wide Complex Tachycardia. Am J Cardiol. 2008; 101:1456-1466. [Full Text]
- Pappas LK, et al. Wide QRS complex supraventricular tachycardia with negative precordial concordance. Am Heart Hosp J. 2009; 7(1):67-8. [PubMed]
- Kappos KG, et al. Wide QRS Complex tachycardia with a negative concordance pattern in the precordial leads: Are the ECG criteria always reliable? Pacing Clin Electrophys. 2006; 29:63-6. [PubMed]
- Volders PGA, et al. Wide QRS complex tachycardia with negative precordial concordance: Always a ventricular origin? J Cardio Electro. 2003; 14:109-111. [PubMed]
- Garmel GM. Wide Complex Tachycardias: Understanding this Complex Condition Part 1 - Epidemiology and Electrophysiology. W J Emerg Med. 2008; 9(1):28-39. [Full Text]
- Ibid. 1, Figure 3.