Rhythm diagnosis in regular wide complex tachycardia: Difference between revisions

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<big>''Assume [[ventricular tachycardia]] until proven otherwise''</big>
==Background==
==Background==
*Ventricular Tachycardia vs. Supraventricular Tachycardia
*Some patients with '''regular''' [[wide complex tachycardia]] do not have [[ventricular tachycardia]]
**<big>'''Assume V-tach until proven otherwise'''</big>
*However, [[ventricular tachycardia]] is a dangerous rhythm that must be treated emergently


== V-Tach vs. [[SVT]]  ==
==Differential Diagnosis==
{{Tachycardia (wide) DDX}}


{| style="width: 500px" cellspacing="1" cellpadding="1" border="1"
==Evaluation==
[[File:Electrocardiogram of Ventricular Tachycardia.png|thumb|Monomorphic ventricular tachycardia]]
[[File:SVT12.jpg|thumb|PSVT at ~180 bpm]]
[[File:Hr scan.jpg|thumb|Termination of PSVT following adenosine]]
{| class="wikitable"
|-
|-
| '''Factor'''<br>
| '''Factor'''<br>
| '''V Tach'''  
| '''[[V-Tach]]'''  
| '''SVT w/ Aberrancy'''
| '''[[SVT]] with Aberrancy'''
|-
|-
| Age  
| Age  
| &gt;50  
| >50  
| &lt;35
| <35
|-
|-
| History  
| History  
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|-
|-
| QRS  
| QRS  
| &gt;0.14sec  
| >0.14sec  
| &lt;0.14sec
| <0.14sec
|-
|-
| Axis  
| Axis  
| Extreme LAD (&lt; -30)  
| Extreme LAD (< -30)  
| Normal or slightly abnl
| Normal or slightly abnormal
|-
|-
| Vagal Maneuvers  
| Vagal Maneuvers  
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|  
|  
V1 or V2 - Broad R wave (&gt;40msec)  
V1 or V2 - Broad R wave (>40msec)  


V6 - Any Q or QS
V6 - Any Q or QS
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|}
|}


== Algorithms ==
==Diagnostic Algorithms==
'''Assume [[ventricular tachycardia]] until proven otherwise'''
*Only for regular rhythms, if irregular consider a-fib with block
*Only for treatment decision if patient is stable


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


=== Brugada Algorithm ===
===Brugada Algorithm===


#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 >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  
##If no then possibly SVT w/ aberrant conduction
**If no then possibly SVT with aberrant conduction


=== aVR Algorithm ===
===aVR Algorithm===


*In lead aVR:
*In lead aVR:


#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 >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  
##If no then SVT
**If no then SVT


=== Niemann Algorithm<ref>James Niemann MD FACEP is EM Faculty at Harbor-UCLA Medical Center and prominent resuscitation researcher</ref> ===
===Niemann Algorithm<ref>James Niemann MD FACEP is EM Faculty at Harbor-UCLA Medical Center and prominent resuscitation researcher</ref>===
 
[[File:Wide Complex Tachycardia.png|thumb|Neimann Algorithm for Regular WCT]]


*Combination of the most specific aspects of the above two algorithms
*Combination of the most specific aspects of the above two algorithms
Acronym: <big>CARMA</big> -> '''Concordance -> aVR ->Regular -> Morphology ->AV dissociation'''
Acronym: <big>CARMA</big> '''Concordance aVR →Regular → Morphology →AV dissociation'''


#Presence of an initial '''R wave in aVR'''? <ref>Vereckei A et al. New algorithm using only lead aVR for differential diagnosis of wide QRS complex tachy- cardia. Heart Rhythm 2008; 5:89-98</ref><ref>Szelenyi Z, et al. Acad Emerg Med 2013;20:1121- 1130</ref>
*Presence of an initial '''R wave in aVR'''? <ref>Vereckei A et al. New algorithm using only lead aVR for differential diagnosis of wide QRS complex tachy- cardia. Heart Rhythm 2008; 5:89-98</ref><ref>Szelenyi Z, et al. Acad Emerg Med 2013;20:1121- 1130</ref>
##If yes then VT  
**If yes then VT  
##If no then continue
**If no then continue
#Is there '''concordance''' (monophasic with same polarity) in all of the precordial leads? <ref>Brugada P et al. A new approach to the differential diagnosis of a regular tachycardia with a wide QRS complex. Circulation 1991;83:1649-1659</ref>
*Is there '''concordance''' (monophasic with same polarity) in all of the precordial leads? <ref>Brugada P et al. A new approach to the differential diagnosis of a regular tachycardia with a wide QRS complex. Circulation 1991;83:1649-1659</ref>
##If yes then VT  
**If yes then VT [[File:concord.jpg|thumb|Example of concordance in precordial leads]] [[File:disconcord.jpg|thumb|Example of disconcordance in precordial leads]]
##If no then continue
**If no then continue
#Is there evidence of '''AV dissociation'''?  
*Is there evidence of '''AV dissociation/Capture beats'''? [[File:capture.jpg|thumb|Example of capture beat]]
##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'''? <ref>Brugada, Circulation; Griffith MJ et al. Lancet 1994;343:386-388</ref><ref>Wellens HJJ et al. Am J Med 1978; 64:27-33</ref>
*Is the QRS '''morphology''' in V1 and V6 consistent with either '''[http://wikem.org/wiki/Left_bundle_branch_block LBBB]''' or '''[http://wikem.org/wiki/Right_bundle_branch_block RBBB]'''? <ref>Brugada, Circulation; Griffith MJ et al. Lancet 1994;343:386-388</ref><ref>Wellens HJJ et al. Am J Med 1978; 64:27-33</ref>
##If no then VT  
**If no then VT  
##If yes then SVT with aberrancy
**If yes then SVT with aberrancy


=== R-Wave Peak Time Method===
===R-Wave Peak Time Method===
#In lead II, if the TIME in (ms) it takes the R wave to go from the isoelectric line to its peak voltage is greater than 50ms, it is VT
*In lead II, if the TIME in (ms) it takes the R wave to go from the isoelectric line to its peak voltage is greater than 50ms, it is VT
#Positive Likelihood ratio of 34.8
*Positive Likelihood ratio of 34.8


=== Lesser Known Criteria===
===Lesser Known Criteria===
*Josephson's sign --- notching or slurring near the nadir of the S-wave is characteristic of V. Tach[[File:Josephson’s sign.jpg|thumbnail|Josephson's Sign Vtach]]
*Rsr' sign --- A taller left R wave in v1-v2 is very specific for VT, as opposed in a RBBB where the second/right R-wave (R') is taller
*"Northwest" axis deviation -- Negative QRS complex in I, AVF and Positive QRS in AVR


Monomorphic Ventricular tachycrdia<br />
==See Also==
 
*[[Wide-complex tachycardia]]
1. Josephson's sign --- notching or slurring near the nadir of the S-wave<br />
2. Rsr' sign --- A taller left R wave in v1-v2 is very specific for VT, as opposed in a RBBB where the second/right R-wave (R') is taller<br />
3. "Northwest" axis deviation -- Negative QRS complex in I, AVF and Positive QRS in AVR
 
== See Also ==
*[[Tachycardia (Wide)]]
*[[SVT]]
*[[SVT]]
*[[ACLS (Main)]]
*[[ACLS: Tachycardia]]
*[[ACLS: Tachycardia]]
*[[PALS (Main)]]
*[[PALS: Tachycardia]]
*[[PALS: Tachycardia]]


== Source  ==
==References==
*James Niemann MD. Harbor-UCLA Grand Rounds 2013
*Pava et al. R-wave peak time at DII: a new criterion for differentiating between wide complex QRS tachycardias. Heart Rhythm. 2010 Jul;7(7):922-6
 
<references/>
<references/>
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Revision as of 07:05, 5 April 2019

Assume ventricular tachycardia until proven otherwise

Background

Differential Diagnosis

Wide-complex tachycardia

Assume any wide-complex tachycardia is ventricular tachycardia until proven otherwise (it is safer to incorrectly assume a ventricular dysrhythmia than supraventricular tachycardia with abberancy)

^Fixed or rate-related

Evaluation

Monomorphic ventricular tachycardia
PSVT at ~180 bpm
Termination of PSVT following adenosine
Factor
V-Tach SVT with 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 abnormal
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

Diagnostic Algorithms

Assume ventricular tachycardia until proven otherwise

  • Only for regular rhythms, if irregular consider a-fib with block
  • Only for treatment decision if patient is stable


Brugada Algorithm

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

aVR Algorithm

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

Niemann Algorithm[1]

Neimann Algorithm for Regular WCT
  • Combination of the most specific aspects of the above two algorithms

Acronym: CARMAConcordance → aVR →Regular → Morphology →AV dissociation

  • Presence of an initial R wave in aVR? [2][3]
    • If yes then VT
    • If no then continue
  • Is there concordance (monophasic with same polarity) in all of the precordial leads? [4]
    • If yes then VT
      Example of concordance in precordial leads
      Example of disconcordance in precordial leads
    • If no then continue
  • Is there evidence of AV dissociation/Capture beats?
    Example of capture beat
    • If yes then VT
    • If no then continue
  • Is the QRS morphology in V1 and V6 consistent with either LBBB or RBBB? [5][6]
    • If no then VT
    • If yes then SVT with aberrancy

R-Wave Peak Time Method

  • In lead II, if the TIME in (ms) it takes the R wave to go from the isoelectric line to its peak voltage is greater than 50ms, it is VT
  • Positive Likelihood ratio of 34.8

Lesser Known Criteria

  • Josephson's sign --- notching or slurring near the nadir of the S-wave is characteristic of V. Tach
    Josephson's Sign Vtach
  • Rsr' sign --- A taller left R wave in v1-v2 is very specific for VT, as opposed in a RBBB where the second/right R-wave (R') is taller
  • "Northwest" axis deviation -- Negative QRS complex in I, AVF and Positive QRS in AVR

See Also

References

  1. James Niemann MD FACEP is EM Faculty at Harbor-UCLA Medical Center and prominent resuscitation researcher
  2. Vereckei A et al. New algorithm using only lead aVR for differential diagnosis of wide QRS complex tachy- cardia. Heart Rhythm 2008; 5:89-98
  3. Szelenyi Z, et al. Acad Emerg Med 2013;20:1121- 1130
  4. Brugada P et al. A new approach to the differential diagnosis of a regular tachycardia with a wide QRS complex. Circulation 1991;83:1649-1659
  5. Brugada, Circulation; Griffith MJ et al. Lancet 1994;343:386-388
  6. Wellens HJJ et al. Am J Med 1978; 64:27-33