Rhythm diagnosis in regular wide complex tachycardia: Difference between revisions

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== V-Tach vs. SVT  ==
== V-Tach vs. SVT  ==


{| cellspacing="1" cellpadding="1" border="1" style="width: 500px;"
{| style="width: 500px" cellspacing="1" cellpadding="1" border="1"
|-
|-
| '''Factor'''<br>  
| '''Factor'''<br>
| '''V Tach'''  
| '''V Tach'''  
| '''SVT w/ Aberrancy'''
| '''SVT w/ Aberrancy'''
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QRS morphology  
QRS morphology  


(RBBB-like pattern)  
(RBBB-like pattern)


|  
|  
V1 - R or qR  
V1 - R or qR  


V6 - rS  
V6 - rS


|  
|  
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QRS morphology  
QRS morphology  


(LBBB-like pattern)  
(LBBB-like pattern)


|  
|  
V1 or V2 - Broad R wave (&gt;40msec)  
V1 or V2 - Broad R wave (&gt;40msec)  


V6 - Any Q or QS  
V6 - Any Q or QS


|  
|  
V1 - rS or&nbsp;QS
V1 - rS or&nbsp;QS  


V6 - qRs
V6 - qRs
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== Algorithms ==
== Algorithms ==


*Only for regular rhythms  
*Only for regular rhythms  
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#Absence of an RS complex in all precordial leads?  
#Absence of an RS complex in all precordial leads?  
##If yes then VT  
##If yes then VT  
##If no then continue  
##If no then continue
#RS interval &gt;100ms in any precordial lead? (onset of R wave to deepest part of S wave)  
#RS interval &gt;100ms in any precordial lead? (onset of R wave to deepest part of S wave)  
##If yes then VT  
##If yes then VT  
##If no then continue  
##If no then continue
#AV dissociation?  
#AV dissociation?  
##If yes then VT  
##If yes then VT  
##If no then continue  
##If no then continue
#Morphology criteria for v-tach present in both V1-2 and V6?  
#Morphology criteria for v-tach present in both V1-2 and V6?  
##If yes then VT  
##If yes then VT  
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#Presence of an initial R wave?  
#Presence of an initial R wave?  
##If yes then VT  
##If yes then VT  
##If no then continue  
##If no then continue
#Presence of an initial r or q wave &gt;40ms  
#Presence of an initial r or q wave &gt;40ms  
##If yes then VT  
##If yes then VT  
##If no then continue  
##If no then continue
#Presence of a notch on descending limb of a negative onset, predominantly negative QRS?  
#Presence of a notch on descending limb of a negative onset, predominantly negative QRS?  
##If yes then VT  
##If yes then VT  
##If no then continue  
##If no then continue
#Ventricular activation-velocity ratio (Vi/Vt) ≤1?  
#Ventricular activation-velocity ratio (Vi/Vt) ≤1?  
##If yes then VT  
##If yes then VT  
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#Presence of an initial R wave in aVR?  
#Presence of an initial R wave in aVR?  
##If yes then VT  
##If yes then VT  
##If no then continue  
##If no then continue
#Is there concordance in all of the precordial leads?  
#Is there concordance&nbsp;(monophasic with same polarity) in all of the precordial leads?  
##If yes then VT  
##If yes then VT  
##If no then continue  
##If no then continue
#Is there evidence of AV dissociation?  
#Is there evidence of AV dissociation?  
##If yes then VT  
##If yes then VT  
##If no then continue  
##If no then continue
#Is the QRS morphology in V1 and V6 consistent with either LBBB or RBBB?  
#Is the QRS morphology in V1 and V6 consistent with either LBBB or RBBB?  
##If no then VT  
##If no then VT  

Revision as of 05:00, 7 January 2012

V-Tach vs. SVT

Factor
 V Tach SVT w/ Aberrancy
Age >50 <35
History MI, CHF, CABG, MVR MVR, WPW
Cannon A Waves Present Absent
Arterial Pulse Variation No variation
First heart sound Variable Not variable
Fusion Beats Present Absent
AV dissociation Present Absent
QRS >0.14sec <0.14sec
Axis Extreme LAD (< -30) Normal or slightly abnl
Vagal Maneuvers No response Slows or terminates

QRS morphology

(RBBB-like pattern)

V1 - R or qR

V6 - rS

V1 - rsR'

V6 - R(slurredS)

QRS morphology

(LBBB-like pattern)

V1 or V2 - Broad R wave (>40msec)

V6 - Any Q or QS

V1 - rS or QS

V6 - qRs

Algorithms

  • Only for regular rhythms
  • Only for treatment decision if pt is stable
  • Assume V-tach until proven otherwise

Brugada Algorithm

  1. Absence of an RS complex in all precordial leads?
    1. If yes then VT
    2. If no then continue
  2. RS interval >100ms in any precordial lead? (onset of R wave to deepest part of S wave)
    1. If yes then VT
    2. If no then continue
  3. AV dissociation?
    1. If yes then VT
    2. If no then continue
  4. Morphology criteria for v-tach present in both V1-2 and V6?
    1. If yes then VT
    2. If no then possibly SVT w/ aberrant conduction

aVR Algorithm

  • In lead aVR:
  1. Presence of an initial R wave?
    1. If yes then VT
    2. If no then continue
  2. Presence of an initial r or q wave >40ms
    1. If yes then VT
    2. If no then continue
  3. Presence of a notch on descending limb of a negative onset, predominantly negative QRS?
    1. If yes then VT
    2. If no then continue
  4. Ventricular activation-velocity ratio (Vi/Vt) ≤1?
    1. If yes then VT
    2. If no then SVT

Niemann Algorithm

  • Combination of the most specific aspects of the above two algorithms
  1. Presence of an initial R wave in aVR?
    1. If yes then VT
    2. If no then continue
  2. Is there concordance (monophasic with same polarity) in all of the precordial leads?
    1. If yes then VT
    2. If no then continue
  3. Is there evidence of AV dissociation?
    1. If yes then VT
    2. If no then continue
  4. Is the QRS morphology in V1 and V6 consistent with either LBBB or RBBB?
    1. If no then VT
    2. If yes then SVT with aberrancy

See Also

Tachycardia (Wide)

Source

  • Brugada et al. A new approach to the differential diagnosis of a regular tachycardia with a wide QRS Complex. Circulation, Vol 83, 1991.
  • Vereckei et al. New algorith using only lead aVR for differential diagnosis of wide QRS complex tachycardia
  • Niemann. Harbor-UCLA Grand Rounds
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