Rhythm diagnosis in regular wide complex tachycardia: Difference between revisions
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<big>''Assume [[ventricular tachycardia]] until proven otherwise''</big> | |||
==Background== | ==Background== | ||
* | *Some patients with '''regular''' [[wide complex tachycardia]] do not have [[ventricular tachycardia]] | ||
*However, [[ventricular tachycardia]] is a dangerous rhythm that must be treated emergently | |||
== | ==Differential Diagnosis== | ||
{{Tachycardia (wide) DDX}} | |||
==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 | | '''[[SVT]] with Aberrancy''' | ||
|- | |- | ||
| Age | | Age | ||
| | | >50 | ||
| | | <35 | ||
|- | |- | ||
| History | | History | ||
Line 40: | Line 47: | ||
|- | |- | ||
| QRS | | QRS | ||
| | | >0.14sec | ||
| | | <0.14sec | ||
|- | |- | ||
| Axis | | Axis | ||
| Extreme LAD ( | | Extreme LAD (< -30) | ||
| Normal or slightly | | Normal or slightly abnormal | ||
|- | |- | ||
| Vagal Maneuvers | | Vagal Maneuvers | ||
Line 73: | Line 80: | ||
| | | | ||
V1 or V2 - Broad R wave ( | V1 or V2 - Broad R wave (>40msec) | ||
V6 - Any Q or QS | V6 - Any Q or QS | ||
Line 84: | Line 91: | ||
|} | |} | ||
== 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 | |||
=== Brugada Algorithm | ===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 | ===aVR Algorithm=== | ||
*In lead aVR: | *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<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''' | |||
*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 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> | |||
**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 | |||
*Is there evidence of '''AV dissociation/Capture beats'''? [[File:capture.jpg|thumb|Example of capture beat]] | |||
**If yes then VT | |||
**If no then continue | |||
*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 yes then SVT with aberrancy | |||
=== R-Wave Peak Time === | ===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[[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 | |||
== See Also | ==See Also== | ||
*[[ | *[[Wide-complex tachycardia]] | ||
*[[SVT]] | *[[SVT]] | ||
*[[ACLS: Tachycardia]] | *[[ACLS: Tachycardia]] | ||
*[[PALS: Tachycardia]] | *[[PALS: Tachycardia]] | ||
== | ==References== | ||
<references/> | <references/> | ||
[[Category: | [[Category:Cardiology]][[Category:Featured]] |
Revision as of 07:05, 5 April 2019
Assume ventricular tachycardia until proven otherwise
Background
- Some patients with regular wide complex tachycardia do not have ventricular tachycardia
- However, ventricular tachycardia is a dangerous rhythm that must be treated emergently
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)
- Regular
- Monomorphic ventricular tachycardia
- PSVT with aberrant conduction:
- PSVT with bundle branch block^
- PSVT with accessory pathway
- Atrial flutter with bundle branch block^
- Sinus tachycardia with bundle branch block^
- Accelerated idioventricular rhythm (consider if less than or ~120 bpm)
- Metabolic
- Irregular
- Atrial fibrillation/atrial flutter with variable AV conduction AND bundle branch block^
- Atrial fibrillation/atrial flutter with variable AV conduction AND accessory pathway (e.g. WPW)
- Atrial fibrillation + hyperkalemia
- Polymorphic ventricular tachycardia
^Fixed or rate-related
Evaluation
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]
- Combination of the most specific aspects of the above two algorithms
Acronym: CARMA → Concordance → 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
- If no then continue
- Is there evidence of AV dissociation/Capture beats?
- 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
- 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
- ↑ James Niemann MD FACEP is EM Faculty at Harbor-UCLA Medical Center and prominent resuscitation researcher
- ↑ 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
- ↑ Szelenyi Z, et al. Acad Emerg Med 2013;20:1121- 1130
- ↑ 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
- ↑ Brugada, Circulation; Griffith MJ et al. Lancet 1994;343:386-388
- ↑ Wellens HJJ et al. Am J Med 1978; 64:27-33