Approach to the Wide Complex Tachycardia

During wide complex tachycardia (heart rate > 100/min, QRS > 0.12 sec) the differentiation between supraventricular and ventricular origin of the arrhythmia is important to guide therapy. Several algorithms have been developed to aid in this differentiation (below). It is important to keep in mind that a good estimate of VT versus SVT can be made based on the clinical vignette:

• 'Horizontal entrance' into the ER. Older patient with previous myocardial infarction = most likely VT
• Younger patient with known paroxysmal tachycardias and who is hemodynamically stable = most like SVT

The ACC algorithm [1]

File:VT algorithm en.png

SVT vs VT algorhytm. Adapted from [1]

Brugada criteria

Morphological criteria (if the above criteria are inconclusive)
LBBB pattern
Initial R more than 40ms?	Yes => VT
Slurred or notched downwards leg of S wave in leads V1 or V2	Yes => VT
Beginning of Q to nadir QS >60 ms in V1 or V2?	Yes => VT	LR >50:1
Q or QS in V6?	Yes => VT	LR >50:1
RBBB pattern
Monofasic R or qR in V1?	Yes => VT
R taller than R' (rabbit-ear sign)?	Yes => VT	LR >50:1
rS in V6?	Yes => VT	LR >50:1

Vereckei algorithm [2]

If the distance traveled on the Y axis in the initial 40ms of the QRS complex is smaller than that traveled in the terminal 40ms of the QRS complex, a VT is much more likely

Examples

• 

  Wide complex tachycardia. No AV dissociation. RBBB. Resembles sinus rhythm from the same patient. Conclusion: SVT with RBBB

• 

  ECG from the same patient in sinus rhythm. The QRS complex is very similiar.

• 

  Wide complex tachycardia. LBBB configuration. Absence of RS in the chest leads. AV dissociation is present. Conclusion: VT

• 

  Wide complex tachycardia. LBBB configuration. Absence of RS in the chest leads. AV dissociation is present. Conclusion: VT

Referenties

1. Blomström-Lundqvist C, Scheinman MM, Aliot EM, Alpert JS, Calkins H, Camm AJ, Campbell WB, Haines DE, Kuck KH, Lerman BB, Miller DD, Shaeffer CW, Stevenson WG, Tomaselli GF, Antman EM, Smith SC Jr, Alpert JS, Faxon DP, Fuster V, Gibbons RJ, Gregoratos G, Hiratzka LF, Hunt SA, Jacobs AK, Russell RO Jr, Priori SG, Blanc JJ, Budaj A, Burgos EF, Cowie M, Deckers JW, Garcia MA, Klein WW, Lekakis J, Lindahl B, Mazzotta G, Morais JC, Oto A, Smiseth O, Trappe HJ, and European Society of Cardiology Committee, NASPE-Heart Rhythm Society. ACC/AHA/ESC guidelines for the management of patients with supraventricular arrhythmias--executive summary. a report of the American college of cardiology/American heart association task force on practice guidelines and the European society of cardiology committee for practice guidelines (writing committee to develop guidelines for the management of patients with supraventricular arrhythmias) developed in collaboration with NASPE-Heart Rhythm Society. J Am Coll Cardiol. 2003 Oct 15;42(8):1493-531. DOI:10.1016/j.jacc.2003.08.013 |
2. Vereckei A, Duray G, Szénási G, Altemose GT, and Miller JM. Application of a new algorithm in the differential diagnosis of wide QRS complex tachycardia. Eur Heart J. 2007 Mar;28(5):589-600. DOI:10.1093/eurheartj/ehl473 |
3. Brugada P, Brugada J, Mont L, Smeets J, and Andries EW. A new approach to the differential diagnosis of a regular tachycardia with a wide QRS complex. Circulation. 1991 May;83(5):1649-59. DOI:10.1161/01.cir.83.5.1649 |