Wide QRS Tachycardia - DDx

•VT

•SVT with Aberrancy•Pre excited SVT

•Antidromic AVRT

•Drugs

•Electrolytes

CriteriaScoresAlgorithms…

The Wide QRS Toolkit

• AV dissociation

• (Rate ?)

• QRS:

• Axis

• Slopes

• Structure

The Wide QRS Toolkit

• AV dissociation

• (Rate ?)

• QRS:

• Axis

• Slopes

• Structure

Fusion Beat

Capture Beat

QRS

• Axis

• Slopes

• Structure

QRS Axis - In Support of VT:

• Concordance

• NW axis

• RBBB + Left axis

• LBBB + Right axis

Concordance

Negative Concordance Positive ConcordanceNegative Positive

(+) concordance

‘Northwest’ axis

LBBB-right axis

RBBB-left axis

QRS

• Axis

• Slopes

• Structure

• Initial 20 ms = NSR• )Initial r in LBBB>30

ms(• Vi/Vt<1 (40ms)• RWPT L2 > 50 ms• )LBBB RS>60 ms(• Any RS>100 ms

Slopes

60

3020

S

40R

40

50

100

20

R

• Initial 20 ms = NSR

Slopes

First 20 ms (0.5 mm!) identical to sinus beat

Normal

AberrantVPB

First 20 ms (0.5 mm!) identical to sinus beat

40

40

Slopes

• Initial 20 ms = NSR• Initial r in LBBB>30

ms• Vi/Vt<1 (40ms)• RWPT L2 > 50 ms• LBBB RS>60 ms• Any RS>100 ms

• Initial 20 ms = NSR• Initial r in LBBB>30

ms• Vi/Vt<1 (40ms)• RWPT L2 > 50 ms• LBBB RS>60 ms• Any RS>100 ms

Slopes

R

In Lead II:R Wave Peak Time (RWPT) > 50 ms

50

II

• Initial 20 ms = NSR• Initial r in LBBB>30 ms

• Vi/Vt<1 (40ms)• RWPT L2 > 50 ms• (LBBB RS>60 ms(

• Any RS>100 ms

Slopes

100S

R

In any lead:RS>100 ms

QRS

• Axis

• Slopes

• Structure

rsR`

rSR`

rsr`

sR

SR

Rs

Triphasic

V6

V1,2

LBBB

Q

Biphasic RBBB

r30

Initial R in aVR

‘Rabbit Ear’ sign

Very Wide QRS

The Vereckei aVR OnlyAlgorithm

2008

• AV dissociation left out

(Inferior/apical origin)

Typical examples of

aVR

40

40

The Vereckei aVR Only Algorithm

Summary: The Wide QRS Toolkit

• AV dissociation

• (Rate ?)

• QRS:

• Axis

• Slopes

• Structure

• Vereckei aVR Only Algorithm

Thank you

The Brugada Algorithm

1991

Onset to nadir of QRS >

100 ms

Any precordial lead

Morphology Criteria

Tachycardia with a right bundle branch block-like QRS

Lead V1Monophasic R or QR or RS favors VTTriphasic RSR' favors SVT

Lead V6R to S ratio <1 (R wave smaller than S wave) favors VTR to S ratio >1 (R wave larger than S wave)favors SVTQS or QR favors VTMonophasic R favors VTTriphasic favors SVT

Tachycardia with a left bundle branch block-like QRS

Lead V1 or V2Any of following R >30 msec, >60 msec to nadir S, notched S favors VT

Lead V6Presence of any Q wave, QR or QS favors VTThe absence of a Q wave in lead V6 favors SVT

…Does all this really matter?

•What happens if we make a mistake?

•Verapamil

•Adenosine?

•ICD?