Wide complex tachycardia differential diagnosis
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor-In-Chief: Rim Halaby
Overview
When wide QRS tachycardia is present on ECG, it is necessary to differentiate whether it is caused by ventricular tachycardia (VT) or supraventricular tachycardia (SVT). In addition to signs on ECG, the clinical history and the age of the patient provide some clues to the nature of the wide QRS tachycardia. While older patients with prior history or myocardial infarction most likely have VT, young hemodynamically stable patients presenting for paroxysmal tachycardias most likely have SVT. Nevertheless, the main differentiating means between VT and SVT relies primarily on ECG findings for which several algorithms have been developed. Examples of these algorithms include Brugada criteria and Vereckei algorithm.[1]
Differential Diagnosis
Differentiating VT from SVT
Brugada Criteria
| Absence of an RS complex in all precordial leads? | Yes? VT (SN=0.21 SP=1.0) | ||||||||||||||||||||||||||||||||||||||||
| No? | |||||||||||||||||||||||||||||||||||||||||
| R to S interval>100 ms in one precordial lead? | Yes? VT (SN=0.21 SP=1.0) | ||||||||||||||||||||||||||||||||||||||||
| No? | |||||||||||||||||||||||||||||||||||||||||
| AV dissociation? | Yes? VT (SN=0.82 SP=0.98) | ||||||||||||||||||||||||||||||||||||||||
| No? | |||||||||||||||||||||||||||||||||||||||||
| Morphology criteria for VT present both in precordial leads V1, V2 and V6? | Yes? VT (SN=0.987 SP=0.965) | ||||||||||||||||||||||||||||||||||||||||
| No? | |||||||||||||||||||||||||||||||||||||||||
| SVT (SN=0.965 SP=0.987) | |||||||||||||||||||||||||||||||||||||||||
Vereckei Criteria
An algorithm has been proposed by Vereckei and colleagues. In addition to to do the traditional criteria, the voltage change on the EKG is used as a final discriminatory criteria. In this method, the voltage change during the initial 40 ms (v(i)) and the terminal 40 ms (v(t)) of the same QRS complex is used to estimate the (v(i)) and terminal (v(t)) ventricular activation velocity ratio (v(i)/v(t)). A v(i)/v(t) > 1 suggests SVT and a v(i)/v(t) ≤ 1 suggests VT.[2]
| AV dissociation present? | Yes? VT | ||||||||||||||||||||||||||||||||||||||||
| No? | |||||||||||||||||||||||||||||||||||||||||
| Initial R wave in aVR present? | Yes? VT | ||||||||||||||||||||||||||||||||||||||||
| No? | |||||||||||||||||||||||||||||||||||||||||
| QRS morphology unlike BBB or FB | Yes? VT | ||||||||||||||||||||||||||||||||||||||||
| No? | |||||||||||||||||||||||||||||||||||||||||
| Vi/Vt≤1? | Yes? VT | ||||||||||||||||||||||||||||||||||||||||
| No? | |||||||||||||||||||||||||||||||||||||||||
| SVT | |||||||||||||||||||||||||||||||||||||||||
Calculation of Vi/Vt
Shown below is an image demonstrating the method used to calculate Vi/Vt. In this tracing, Vi/Vt is < 1 is suggestive of ventricular tachycardia according to Vereckei criteria.
ACC Algorithm
| Wide QRS complex tachycardia (QRS duration greater than 120 ms) | |||||||||||||||||||||||||||||||||||||||||||||||||||
| Regular or irregular? | |||||||||||||||||||||||||||||||||||||||||||||||||||
| Regular | Irregular | ||||||||||||||||||||||||||||||||||||||||||||||||||
| Is QRS identical to that during SR? If yes, consider: - SVT and BBB - Antidromic AVRT | Atrial fibrillation Atrial flutter / AT with variable conduction and: a) BBB or b) Antegrade conduction via AP | ||||||||||||||||||||||||||||||||||||||||||||||||||
| Vagal maneuvers or adenosine | |||||||||||||||||||||||||||||||||||||||||||||||||||
| Previous myocardial infarction or structural heart disease? If yes, VT is likely. | |||||||||||||||||||||||||||||||||||||||||||||||||||
| 1 to 1 AV relationship? | |||||||||||||||||||||||||||||||||||||||||||||||||||
| Yes or unknown | No | ||||||||||||||||||||||||||||||||||||||||||||||||||
| V rate faster than A rate | A rate faster than V rate | ||||||||||||||||||||||||||||||||||||||||||||||||||
| QRS morphology in precordial leads | VT | Atrial tachycardia Atrial flutter | |||||||||||||||||||||||||||||||||||||||||||||||||
| Typical RBBB or LBBB | Precordial leads: - Concordant - No R/S pattern - Onset of R to nadir longer than 100ms | RBBB pattern: - qR, Rs or Rr' in V1 - Frontal plane axis range from +90 degrees to -90 degrees | LBBB pattern: - R in V1 longer than 30 ms - R to nadir of S in V1 greater than 60 ms - qR or qS in V6 | ||||||||||||||||||||||||||||||||||||||||||||||||
| SVT | VT | VT | VT | ||||||||||||||||||||||||||||||||||||||||||||||||
The above algorithm is adapted from the American College of Cardiology.
References
- ↑ http://en.ecgpedia.org/wiki/Approach_to_the_Wide_Complex_Tachycardia
- ↑ Vereckei A, Duray G, Szénási G, Altemose GT, Miller JM (2007). "Application of a new algorithm in the differential diagnosis of wide QRS complex tachycardia". European Heart Journal. 28 (5): 589–600. doi:10.1093/eurheartj/ehl473. PMID 17272358. Retrieved 2012-10-13. Unknown parameter
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