APPROACH TO WIDE QRS COMPLEX TACHYCARDIA

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APPROACH TO WIDE QRS COMPLEX TACHYCARDIA

• Dr HA TUAN KHANH
• Dr DAVID TRAN

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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

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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
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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

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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
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SVT vs VTPhysical 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

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SVT vs VT
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SVT vs VTECG criteria Brugada algorithm
Brugada P. Ciculation 1991
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Step 1
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Step 2
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Step 3
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Step 4 LBBB - type wide QRS complex
VT
SVT
R wave gt40ms
notching of S wave
small R wave
V1
fast downslope of S wave
gt 70ms
Q wave
V6
no Q wave
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Step 4 RBBB - type wide QRS complex
VT
SVT
qR (or Rs) complex
monophasic R wave
rSR configuration
V1
or
R/S gt 1
R/S ratio lt 1
QS complex
V6
or
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Step 4 RBBB morphology
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Step 4 LBBB morphology
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Other ECG criteria

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

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Concordance and Northwest Axis
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Fusion beat and capture beat
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Ventriculoatrial conduction with block
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RBBB morphology with LAD
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LBBB morphology with RAD
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Previous MI
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Previous LBBB
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Findings favoring SVT

• Triphasic pattern in V1 and V6
• Rabbits ear
• Previous ECG Preexistent BBB or preexcitation

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Triphasic pattern
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Rabbits ear
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Wide complex SVT from preexisting RBBB
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Wide complex SVT from preexisting LBBB
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VT vs AVRTECG criteria
Brugada P. Ciculation 1991
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Wide complex SVT from bypass tract
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Summary diagnosis evaluation
ACC/AHA/ESC guidelines for management of pt with
SVT. Circulation 2003
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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

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

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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

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Acute management hemodynamically stable and
regular tachycardia
ACC/AHA/ESC guidelines for management of pt with
SVT. Circulation 2003
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Recommendation acute management hemodynamically
stable and regular tachycardia
ACC/AHA/ESC guidelines for management of pt with
SVT. Circulation 2003
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Tachycardia algorithm
AHA Guidelines for Cardiopulmonary Resuscitation
and Emergency Cardiovascular Care. Ciurculation
2005
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Tachycardia algorithm
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Thank you for your attention