approach to wide qrs complex tachycardia dr ha tuan khanh dr david tran
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APPROACH TO WIDE QRS COMPLEX APPROACH TO WIDE QRS COMPLEX TACHYCARDIATACHYCARDIA
Dr HA TUAN KHANHDr HA TUAN KHANH
Dr DAVID TRANDr DAVID TRAN
ContentContent
1. Definition
2. Causes of WCT
3. Diagnosis criteria Clinical history Physical examination ECG criteria: Brugada criteria, other criteria, findings favoring
SVT, VT vs AVRT criteria
4. Management Unstable hemodynamic Stable hemodynamic
DefinitionDefinition
Wide QRS complex tachycardia is a rhythm with a rate of more than
100 b/m and QRS duration of more than 120 ms
VT (80%)
SVT (20%)
Stewart RB. Ann Intern Med 1986
• Supraventricular tachycardia
- with prexsisting BBB
- with BBB due to heart rate (aberrant conduction)
- antidromic tachycardia in WPW syndrome
• Ventricular tachycardia
Causes of wide QRS complex tachycardia
SVT vs VT Clinical history
Medication Drug-induced tachycardia → Torsade de pointes
Diuretics
Digoxin-induced arrhythmia → [digoxin] ≥2ng/l or normal if hypokalemia
Age - ≥ 35 ys → VT (positive predictive value of 85%)
Underlying heart disease Previous MI → 98% VT
Pacemakers or ICD Increased risk of ventricular tachyarrhythmia
SVT vs VTSVT vs VTPhysical examination 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
SVT vs VTECG criteria: Brugada algorithm
Brugada P. Ciculation 1991
Step 1
Step 2
Step 3
Step 4: LBBB - type wide QRS complex
SVT VT
small R wave notching of S waveR wave >40ms
fast downslopeof S wave
no Q wave
Q wave
> 70ms
V1
V6
Step 4: RBBB - type wide QRS complex
SVT VT
V1
V6
or
or
R/S > 1 R/S ratio < 1 QS complex
rSR’ configuration monophasic R wave qR (or Rs) complex
Step 4: RBBB morphology
Step 4: LBBB morphology
Other ECG criteriaOther 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
Concordance and Northwest Axis
Fusion beat and capture beat
Ventriculoatrial conduction with block
RBBB morphology with LAD
LBBB morphology with RAD
Previous MI
Previous LBBB
Findings favoring SVTFindings favoring SVT
• Triphasic pattern in V1 and V6• Rabbit’s ear• Previous ECG: Preexistent BBB or preexcitation
Triphasic patternTriphasic pattern
Rabbit’s earRabbit’s ear
Wide complex SVT from preexisting RBBBWide complex SVT from preexisting RBBB
Wide complex SVT from preexisting LBBBWide complex SVT from preexisting LBBB
VT vs AVRTVT vs AVRTECG criteriaECG criteria
Brugada P. Ciculation 1991
Wide complex SVT from bypass tractWide complex SVT from bypass tract
Summary : diagnosis evaluationSummary : diagnosis evaluation
ACC/AHA/ESC guidelines for management of pt with SVT. Circulation 2003
Management – Hemodynamic compromiseManagement – Hemodynamic compromise
1. 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
2. Unstable patient, unresponsive or pulseless → standard ACLS resusciation algorithms
ACLS pulseless arrest algorithmACLS pulseless arrest algorithm
AHA Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Ciurculation 2005
Management – Stable hemodynamicManagement – Stable hemodynamic
1. 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
Management – Stable hemodynamicManagement – Stable hemodynamic
2. 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
Acute management hemodynamically stable and regular tachycardiaAcute management hemodynamically stable and regular tachycardia
ACC/AHA/ESC guidelines for management of pt with SVT. Circulation 2003
Recommendation acute management hemodynamically stable Recommendation acute management hemodynamically stable and regular tachycardiaand regular tachycardia
ACC/AHA/ESC guidelines for management of pt with SVT. Circulation 2003
Tachycardia algorithmTachycardia algorithm
AHA Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Ciurculation 2005
Tachycardia algorithmTachycardia algorithm
Thank you for your attentionThank you for your attention
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