1. APPROACH TO WIDE QRS COMPLEX TACHYCARDIA
Dr HA TUAN KHANH
Dr DAVID TRAN

2. Content Definition Causes of WCT Diagnosis criteria Clinical history
Physical examination
ECG criteria: Brugada criteria, other criteria, findings favoring SVT, VT vs AVRT criteria
Management
Unstable hemodynamic
Stable hemodynamic

3. Stewart RB. Ann Intern Med 1986
Definition
Wide QRS complex tachycardia is a rhythm with a rate of more than 100 b/m and QRS duration of more than 120 ms
SVT (20%)
VT (80%)
Stewart RB. Ann Intern Med 1986

4. Causes of wide QRS complex tachycardia
Supraventricular tachycardia
- with prexsisting BBB
- with BBB due to heart rate (aberrant conduction)
- antidromic tachycardia in WPW syndrome
Ventricular tachycardia

5. SVT vs VT Clinical history
Age
- ≥ 35 ys → VT (positive predictive value of 85%)
Underlying heart disease
Previous MI → 98% VT
Pacemakers or ICD
Increased risk of ventricular tachyarrhythmia
Medication
Drug-induced tachycardia → Torsade de pointes
Diuretics
Digoxin-induced arrhythmia → [digoxin] ≥2ng/l or normal if hypokalemia

6. SVT vs VT Physical examination
Physical findings that indicate presence of AV dissociation (cannon A waves, variable-intensity S1,variation in BP unrelated to respiration) if present are useful
Termination of WCT in response to maneuvers like Valsalva, carotid sinus pressure, or adenosine is strongly in-favor of SVT but there are well-documented cases of VT responsive to these

7. SVT vs VT ECG criteria: Brugada algorithm
Brugada P. Ciculation 1991

8. Step 1

9. Step 2

10. Step 3

11. Step 4: LBBB - type wide QRS complex
SVT VT
R wave >40ms
small R wave
notching of S wave V1
fast downslope
of S wave
> 70ms V6
Q wave
no Q wave

12. Step 4: RBBB - type wide QRS complex
SVT VT
rSR’ configuration
monophasic R wave
qR (or Rs) complex V1 or
R/S > 1
R/S ratio < 1
QS complex V6 or

13. Step 4: RBBB morphology

14. Step 4: LBBB morphology

15. Other ECG criteria North - west QRS axis deviation
Negative or positive concordance
Fusion beats, capture beats
Ventriculoatrial conduction with block
RBBB morphology with LAD > - 300
LBBB morphology with RAD > + 900
Previous ECG show MI or previous ECG show that during sinus rhythm, bifascular block is present, which changes in configuration during tachycardia

16. Concordance and Northwest Axis

17. Fusion beat and capture beat

18. Ventriculoatrial conduction with block

19. RBBB morphology with LAD

20. LBBB morphology with RAD

21. Previous MI

22. Previous LBBB

23. Findings favoring SVT Triphasic pattern in V1 and V6 Rabbit’s ear
Previous ECG: Preexistent BBB or preexcitation

24. Triphasic pattern

25. Rabbit’s ear

26. Wide complex SVT from preexisting RBBB

27. Wide complex SVT from preexisting LBBB

28. VT vs AVRT ECG criteria
Brugada P. Ciculation 1991

29. Wide complex SVT from bypass tract

30. Summary : diagnosis evaluation
ACC/AHA/ESC guidelines for management of pt with SVT. Circulation 2003

31. Management – Hemodynamic compromise
Unstable patient, but still responsible with a discernible BP and/or pulse:
- Emergent synchronized cardioversion
- If the QRS complex and T wave cannot be distinguished accurately → immediate defibrillation
Unstable patient, unresponsive or pulseless → standard ACLS resusciation algorithms

32. ACLS pulseless arrest algorithm
AHA Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Ciurculation 2005

33. Management – Stable hemodynamic
VT or WCT of uncertain etiology:
Any associated conditions (cardiac ischemia, heart failure, electrolyte abnormalities or drug toxicities)
Class I and III antiarrhythmic drugs
- Amiodarone: 150mg IV/10mins followed by an infusion of 1mg/min for 6 hours, then 0,5mg/min
- Procainamide: 15-18mg/kg infusion over 25-30mins, followed by 1-4mg/min by continuous infusion
- Lidocaine: 1-1,5mg/kg IV/2-3mins followed by an infusion of 1-4mg/min
Urgent or elective cardioversion

34. Management – Stable hemodynamic
SVT
Vagal maneuvers: carotid sinus pressure (if no carotid bruits) or Valsava maneuver
Adenosine: 6mg over 1-2 seconds. If the initial dose is ineffective, a 12mg dose may be given and repeated once if necessary
Calcium channel blocker (Verapamil 2.5 to 5mg IV) or beta blokers (Metoprolol 5 to 10 mg IV)
Cardioversion

35. Acute management hemodynamically stable and regular tachycardia
ACC/AHA/ESC guidelines for management of pt with SVT. Circulation 2003

36. ACC/AHA/ESC guidelines for management of pt with SVT. Circulation 2003
Recommendation acute management hemodynamically stable and regular tachycardia
ACC/AHA/ESC guidelines for management of pt with SVT. Circulation 2003

37. Tachycardia algorithm
AHA Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Ciurculation 2005

38. Tachycardia algorithm

39. Thank you for your attention