WIDE QRS TACHYCARDIA

WIDE QRS TACHYCARDIA

1. MSN PAVAN KUMAR
Wide QRS Tachycardia

2. Wide complex tachycardia
Definitions
Causes
Features for differentiation
Diagnostic approach/algorithms

3. Definition :
A rhythm with QRS duration ≥ 120 ms and heart rate > 100/min.
Sustained vs non sustained
Wide complex tachycardia

4. Causes :
Regular :
1.Ventricular tachycardia(80% of WCT)
2.Any SVT with aberrancy (2
nd
MC WCT)
3.Any SVT with BBB
4.Any SVT with delayed conduction d/t drugs and electrolytes
a.Class IA,IC ; hyperkalemia.
5.Antidromic AVRT(1-5%)
6.Pacemaker mediated rhythm
Irregular :
1.AF with conduction on preexcitation pathway.
2.Any irregular SVT with aberrancy , BBB .
3.VT in the 1
st
30 sec , pts on anti arrythmitic drugs – cycle length
varibility.
Wide complex tachycardia

5. Pacemaker rhythm(<1% of WCT)
1.History and physical examination
2.ECG:
a.Stimulus artefact
b.LBBB with left superior axis(if RV apical pacing) , various
combinations ( biventricular pacing)
Wide complex tachycardia
Features for differentiation :

6. VT vs Preexcited tachycardia
•VT
–Predominantly negative QRS complexes in V4-V6
–Presence of a QR complex in one or more leads V2-V6
–More QRS complex than P
•75% sensitivity & 100% specificity for VT (Stierer et al)
Wide complex tachycardia
Features for differentiation :

7. Features for differentiation :
History and physical examination:
1.H/o heart disease – previous MI , angina , CHF – have a PPA of 95%
for diagnosing VT
2.Pts with VT are older than SVT (> 35 yrs)
3.SVT-A often have h/o previous episode(>3years)
4.Pts with SVT-A are hemodynamically stable.
5.Examination for AV dissociation
a.Cannon A waves in JVP
b.Variable S1 intensity
c.Variation in SBP unrelated to respiration.
6.Termination of WCT with physical manoeuvres and medications
Wide complex tachycardia

8. Features for differentiation by ECG :
1.QRS duration
2.QRS axis
3.Concordant pattern
4.Precordial RS duration.
5.Morphological criteria - RBBB , LBBB , ambiguous chest lead pattern
6.Q wave presence
7.AV dissociation
8.Baseline QRS prolongation – QRS duration , QRS configuration.
9. aVR changes.
10.Lead II R-wave-peak-time (RWPT) criterion .
Wide complex tachycardia

9. 1.QRS duration :
> 160 ms with LBBB , >140 ms with RBBB - VT
Wellens et al . Showed that 69% of VT had QRS duration of
>140ms and none of SVT-A showed QRS duration of >140ms.
Exceptions:
a.Anti arrythmitic drugs non specifically prolong QRS duration.
b.Pts with structurally normal heart may have VT with QRS
duration of 120-140ms.(<140ms in12% , < 120 ms in 4%)
c.QRS duration also depend site of origin of VT , septal VT
Wide complex tachycardia
QRS duration has sensitivity of 70%

10. Wide complex tachycardia

11. 2.QRS axis :
Frontal plane axis of -90 to +180 --- VT
Shift in QRS axis of more than 40 from baseline --- VT(less
specific)
RBBB with LAD, LBBB with RAD --- VT.
LAFB (-30 to -90) ,
LPFB (+110 to150) and
RBBB (normal axis).
Wide complex tachycardia

12. 3.Concordant QRS in chest leads:
Concordant QRS in chest leads is diagnostic of VT uncommon in
SVT-A.
Exceptions:
Positive concordance (ventricular activation begins left
posteriorly) seen in VT originating in Lt post wall or SVT using a
left posterior accessory pathway for AV conduction.
If no additional criteria for WPW are absent don’t consider it
because of low incidence(<6%)
Wide complex tachycardia
Specificity of 90%, Sensitivity of 20%

13. Wide complex tachycardia

14. 3.Concordant QRS in limb leads :
The presence of predominantly negative QRS complexes in leads
1,2,3 is suggestive of VT
This is another way to describe right superior axis
Similar to RS axis it is considered as highly specific for VT
Wide complex tachycardia

15. 4.Pericardial RS duration criteria :
If concordant QRS complexes are absent i.e with RS complex
onset of R wave to nadir of S wave > 100 ms.
Wide complex tachycardia
Sensitivity – 66%
Specificity - 98%

16. 5.RBBB – V1 :
rSr , rSR , rR , rsr patterns consistent with SVT-A
R , R>30ms with any negative QRS , qR --- VT
This is because right ventricle doesn’t participate in initial QRS
Wide complex tachycardia
Sensitivity – 30-80%
Specificity - 84-95%

17. 5.RBBB – V6 :
qRs , Rs , RS with R/S >1 --- SVT –A
R , QR , QS , RS with R/S < 1 --- VT
Wide complex tachycardia
Sensitivity – 30-60%
Specificity - 80-100%

18. 5.LBBB – V1,V6:
Wide complex tachycardia
Sensitivity – 100%
Specificity - 89%
Sensitivity – 17%
Specificity - 100%

19. 5.Ambiguous chest lead pattern:
W and M pattern in V1 have been classified as LBBB & RBBB
Because they are ambiguous in this way, they are unlikely to
represent typical aberration and are highly specific for VT.
Sensitivity of 60-80% , specificity of 90-95%.
Wide complex tachycardia

20. 6.Q wave presence :
Q during WCT --- suggest old MI --- VT most likely.
In general pts with post MI VT maintain Q wave during WCT that
are present during baseline in the same lead.
Exceptions :
1.Pts with DCMP will have Q wave during VT that are not present
during baseline.
2.PSEUDO Q wave with retrograde p wave deforming QRS can
be seen in SVT-A
3.Preexcited tachycardia with posterior AV connection can have Q
wave in inferior leads
Wide complex tachycardia

21. 7.AV dissociation :
The most specific ECG finding for VT .
Clues for AV dissociation:
1.Clinically by cannon A waves , variable intensity of S1 , Variation
in SBP unrelated to respiration.
2. AV dissociation
3.AV ratio of less than 1
4.2:1 VA block(d/t retrograde conduction)
5.Variation in QRS amplitude during WCT
6.Fusion & capture beats
7.Recording separate atrial electro gram
(oesophageal/transvenous)
8.Echo (evaluating RA contraction in relation to ventricular)
Wide complex tachycardia

22. 7.AV dissociation :
Wide complex tachycardia
V rate = 215/mt
A rate = 125/mt
A/V =0.58

23. 7.AV dissociation :
Wide complex tachycardia
VT with retrograde 2:1 VA conduction (seen in 15-20% of VT)

24. Variation in amplitude of QRS during WCT
1.Scalar summation of P wave with QRS
2.Variable ventricular filling in the presence of AVD
Presence of multiple WCT configuration has a sensitivity of 55%
for diagnosing VT
7.AV dissociation :
Wide complex tachycardia

25. The QRS complex is prolonged, and the R-R interval is regular
except for occasional capture beats (C) that have a normal contour
and are slightly premature. Complexes intermediate in contour
represent fusion beats (F).
 Thus, even though atrial activity is not clearly apparent,
atrioventricular dissociation is present during ventricular
tachycardia and produces intermittent capture and fusion beats
7.AV dissociation :
Wide complex tachycardia

26. 7.AV dissociation :
Wide complex tachycardia

27. Caveats while using AVD:
1.Low sensitivity (20-50%) is d/t fast heart rates , inadequate
duration of recording , observer inexperience.
2.30% of pts , especially VT with low V rate , have 1:1 VA
conduction – differentiate by vagal maneuvers , adnosine.
3.AF and VT co exist AVD cannot be diagnosed .
7.AV dissociation :
Wide complex tachycardia
Sensitivity – 20-50%
Specificity – 98%

28. 8.Base line QRS prolongation:
a. Pt with baseline QRS rhythm and WCT QRS different – VT
1.QRS during VT is narrower than baseline rhythm
2.Contra lateral BBB in baseline rhythm and during WCT
3.AV dissociation
4.Rarely other findings may be useful like precordial concordance ,
north-west axis , monophasic R wave in V1
Wide complex tachycardia
Pts with BBRTImpulse originates in RBBTravels through LBB
Have typical features of LBBB

29. 9.aVR changes :
1.Presence of initial ‘r’ wave in aVR
2.Presence of initial ‘r’ or ‘q’ wave of > 40ms duration
3.Presence of notch in descending limb of negative onset and
predominantly negative QRS
4.Vi/Vt ≤ 1
All the above features are indicative of VT
Wide complex tachycardia
Sensitivity – 96.7%
Specificity – 99%

30. 9. aVR changes : Initial ‘r’
wave in aVR
Wide complex tachycardia
During SVT with aberrancy ,
initial septal activation and main
ventricular activation are
directed away from lead aVR
 negative QRS complex
Exceptions :
1.Inferior MI- initial r wave (rS complex) during NSR or SVT
2.VT originating from base of heart may not have initial r wave

31. Wide complex tachycardia
9.aVR changes :

32. Vi = voltage in the initial 40ms of QRS
Vt = voltage in the terminal 40ms of QRS
In SVT-A only one portion is bundle branch is blocked --- so the
initial portion of QRS is rapid compared to terminal portion.
In VT slow muscle to muscle spread of impulse causes slower
voltage changes through out QRS complex
Can be applied to any lead
The vi/vt was > 1 (signifying supraventricular origin) in 88%
tracings with LBBB pattern, in 98% with RBBB pattern, and
90% with nonspecific IVCD.
Wide complex tachycardia
9.aVR changes : Vi/Vt ≤ 1

33. Wide complex tachycardia
9.aVR changes : Vi/Vt ≤ 1

34. 10.Lead II R-wave-peak-time (RWPT) criterion : Pavas criteria
Wide complex tachycardia
RWPT > or =50 ms at DII is a
simple and highly sensitive
criterion that discriminates VT
from SVT in patients with wide
QRS complex tachycardia.
Heart Rhythm. 2010 Jul;7(7):922-6. Epub 2010 Mar 4.
Sensitivity and
specificity of 97%

35. Diagnostic approach/algorithms
1.Wellens(1978) , Akhtar(1988) ,
2.Brugada(1991)
3.Griffith(1994)
4.Bayesian(1995)
5.aVR algorithms(2007)
6.lead II R-wave-peak-time (RWPT) criterion(2010)
7.Combined .
Wide complex tachycardia

36. Wide complex tachycardia
Diagnostic approach/algorithms
WELLENS CRITERIA
AKHTAR CRITERIA

37. Wide complex tachycardia
Diagnostic approach/algorithms
Sensitivity – 98.7%
Specificity – 96.5%
Brugada P, Brugada Jet al.A new approach to the
DD of a regular tachycardia with a wide QRS
complex. Circulation. 1991;83:1649-16595
BRUGADA CRITERIA

38. WCT
Wide complex tachycardia
Diagnostic approach/algorithms
NO YES
INDEPENDENT P WAVES
YES
VT
Griffith MJ,Garratt Ci,et VT as default diagnosis in
broad complex tachycardia. Lancet 1994 feb
Sensitivity – 95%
Specificity – 64%
GRIFFITH CRITERIA

39. Wide complex tachycardia
Diagnostic approach/algorithms
BAYESIAN CRITERIA
CRITERIA LR
QRS WIDTH
=140MS
140-160MS
> 160MS
0.31
0.48
22.86
QRS AXIS
NW AXIS
RBBB + LAD
LBBB + RAD
NONE
7.86
8.21
3.93
0.47
V WAVE IN RBBB
TALLER LT PEAK
Rs OR qR
rsR OR rR
NONE

50
4.03
0.21
1.41
V WAVE IN LBBB
r > 40MS
NOTCH IN ‘S’
R-S > 60MS
NONE
50
50
50
0.13
INTRINSICOID IN V6
= 60MS
< 60MS
19.3
0.46
V6 MORPHOLOGY
QS
BIPHASIC RBBB R/S<1
TRIPHASIC RBBB R/S<1
50
50
0.13
Sensitivity – 95%
Specificity – 52%

40. Wide complex tachycardia
Diagnostic approach/algorithms aVR CRITERIA
Heart Rhythm, , Vereckei, A. et al. New
algorithm using only lead aVR for DD of wide
QRS complex tachycardia., 2008
Sensitivity – 96.7%
Specificity – 99%

41. Wide complex tachycardia
Diagnostic approach/algorithms
Sen.10%
Spe.100%
Sen.48%
Spe.98%
Sen.89%
Spe.89%
Sen.95%
Spe.80%
The sensitivity [95.7 vs.
88.2, P < 0.001] and NPV
[83.5% vs. 65.3% for VT
diagnosis of the new
algorithm were superior to
those of the Brugada criteria
Application of a new algorithm in the DD
of wide QRS complex tachycardia Andra´s
Vereckei et al . EHJ 2007.

42. Wide complex tachycardia
ALGORITHM ORIGINAL STUDY
SEN. SPEF.
LAU & NG(2001)
SEN. SPE.
ISENHOUR(2000)
SEN SPE.
BRUGADA 98.7 96.592 4479-91 43-70
GRIFFITH 95 6492 44
BAYESIAN 95 5297 56
Diagnostic approach/algorithms

43. Comparison of five electrocardiographic methods for differentiation
of wide QRS-complex tachycardias
Brugada, Bayesian, Griffith, and aVR algorithms, and the lead II R-
wave-peak-time (RWPT) criterion
All five algorithms/criteria had equal moderate diagnostic accuracy.
The newer methods were not more accurate than the classic Brugada
algorithm
Wide complex tachycardia
Diagnostic approach/algorithms
Comparison of five electrocardiographic methods for differentiation
of wide QRS-complex tachycardias.Jastrzebski.M Europace 2010 feb
14

44. Best algorithmic approach for diagnosing WCT
1.BRUGADA
2.aVR criteria
3.Vereckei combined criteria(old & aVR criteria)
Wide complex tachycardia

45. Wide complex
tachycardia