Rhythm diagnosis in regular wide complex tachycardia: Difference between revisions
(Monomorphic VT clues)
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=== Lesser Known Criteria===
=== Lesser Known Criteria===


Josephson's sign --- notching or slurring near the nadir of the S-wave
Monomorphic Ventricular tachycrdia


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
1. Josephson's sign --- notching or slurring near the nadir of the S-wave
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
3. "Northwest" axis deviation -- Negative QRS complex in I, AVF and Positive QRS in AVR


== See Also  ==
== See Also  ==

Revision as of 16:46, 10 July 2014

Background

  • Ventricular Tachycardia vs. Supraventricular Tachycardia
    • Assume V-tach until proven otherwise

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[1]

  • Combination of the most specific aspects of the above two algorithms

Acronym: CARMA -> Concordance -> aVR ->Regular -> Morphology ->AV dissociation

  1. Presence of an initial R wave in aVR? [2][3]
    1. If yes then VT
    2. If no then continue
  2. Is there concordance (monophasic with same polarity) in all of the precordial leads? [4]
    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? [5][6]
    1. If no then VT
    2. If yes then SVT with aberrancy

R-Wave Peak Time Method

  1. 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
  2. Positive Likelihood ratio of 34.8

Lesser Known Criteria

Monomorphic Ventricular tachycrdia

1. Josephson's sign --- notching or slurring near the nadir of the S-wave 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 3. "Northwest" axis deviation -- Negative QRS complex in I, AVF and Positive QRS in AVR

See Also

Source

  • 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
  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
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