Download wide qrs tachycardia

WIDE QRS TACHYCARDIA BEDSIDE DIAGNOSIS
Dr.K.Chandrasekaran.MD.DM
Interventional cardiologist and
Cardiac Electrophysiologist
CLASSIFICATION OF TACHYCARDIAS
WITH A BROAD QRS COMPLEX

SVT WITH BBB

ATRIAL TACHYCARDIA
ATRIAL FLUTTER
ATRIAL FIBRILLATION
AV NODAL RE-ENTRANT TACHYCARDIA
CMT WITH AV CONDUCTION OVER AV NODE AND VA
CONDUCTION OVER ACC PATHWAY
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SVT WITH AV CONDUCTION OVER ACC
PATHWAY
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ATRIAL TACHYCARDIA
ATRIAL FLUTTER
ATRIAL FIBRILLATION
AV NODAL RE-ENTRANT TACHYCARDIA

Antidromic circus movement tachycardia
using an accessory pathway in the antegrade
direction and AV Node or another acc
pathway in the retrograde direction
 AV Reentry tachycardia using a Mahaim
fibre in the antegrade direction and AV
Node or another acc pathway in the
retrograde direction
VENTRICULAR TACHYCARDIA
VT
Regular
SVT with BBB
SVT with AV
conduction
Over accessory
pathway
BBB
AF
Irregular
Accessory
Pathway
PMVT with Normal
QT
PMVT with long
QT
THE ECG DIAGNOSIS
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IMPORTANCE OF AV DISSOCIATION
AVD HALLMARK OF VT .
VA CONDUCTION DURING SLOW VT.
P WAVES CAN BE DIFFICULT TO RECOGNISE
NON ECG SIGNS
FUSION CAPTURE BEATS
AVD IN AVJT WITH BBB AFTER CARDIAC SURGERY OR
DURING DIG INTOXICATION
A 47 year old man with a long history of
palpitations and blackouts.
A 23 year old male with palpitations
WIDTH OF QRS COMPLEX

SITE OF ORIGIN OF VT

ORIGIN IN THE LATERALFREE WALL  VERY
WIDE QRS ( SEQUENTIAL ACTIVATION OF THE
VENTRICLES)
ORIGIN IN OR CLOSE TO THE IVS  NARROWER
QRS ( SIMULTANEOUS ACTIVATION OF THE
VENTRICLES )
SCAR TISSUE , VENTRICULAR HYPERTROPHY
AND MUSCULAR DISARRAY
QRS WIDTH > 0.14 SECS IN RBBB TACHYCARDIAS
AND > 0.16 SECS IN LBBB TACHYCARDIAS 
ARGUES FOR A VT.
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WIDTH OF QRS COMPLEX
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SVT WITH QRS WIDTH > 0.14 SECS (RBBB) OR
> 0.16 SECS (LBBB) IN THREE CONDITIONS:
IN THE PRESENCE OF BBB IN THE ELDERLY
WITH FIBROSIS IN THE BB SYSTEM AND
VENTRICULAR MYOCARDIUM
DURING SVT WITH AV CONDUCTION OVER AN
ACCESSORY AV PATHWAY
WHEN CLASS 1 C DRUGS ARE PRESENT DURING
SVT
QRS AXIS IN THE FRONTAL PLANE
SUPERIOR AXIS  VT ORIGIN IN THE
APICAL PART OF THE VENTRICLE.
 RBBB SHAPED QRS + SUPERIOR AXIS  VT
 INFERIOR AXIS  VT ORIGIN IN THE
BASAL VENTRICLE.
 LBBB SHAPED QRS + INFERIOR AXIS VT

CONFIGURATIONAL CHARACTERISTICS OF
THE QRS COMPLEX
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RBBB SHAPED TACHYCARDIA
qR OR R IN VI  VT
rSR PATTERN IN VI  SVT
R/S RATIO < 1 IN V6  VT
R/S RATIO < 1 IN V6 TYPICALLY FOUND WITH LEFT AXIS
DEVIATION.
WITH INFERIOR AXIS V6 OFTEN SHOWS R/S RATIO > 1
qRS in V6 with R/S in V6 >1 ---- SVT
CONFIGURATIONAL CHARACTERISTICS OF
THE QRS COMPLEX
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LBBB SHAPED VT
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V1,V2 SHOW INITIAL POSITIVE QRS ( r wave)> 30
mSecs,
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SLURRING / NOTCHING OF THE DOWN STROKE OF
THE S-WAVE,
AN INTERVAL BETWEEN THE BEGENNING OF QRS
AND THE NADIR OF THE S-WAVE OF 70 msecs .
qR PATTERN IN V6  VT IS MORE LIKELY
CONFIGURATIONAL CHARACTERISTICS OF
THE QRS COMPLEX
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SVT WITH LBBB
V1 SHOWS NO OR MINIMAL INITIAL POSITIVITY,
A VERY RAPID DOWNSTROKE OF THE SWAVE
A SHORT INTERVAL BETWEEN THE BEGENNING
OF THE QRS AND THE NADIR OF THE SWAVE
INTERVAL ONSET QRS TO NADIR OF
SWAVE IN PRECORDIAL LEADS
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RS INTERVAL > 100 msecs IN 1 OR MORE
PRECORDIAL LEADS  VT
DIFFERENTIAL DIAGNOSIS
SVT WITH AV CONDUCTION OVER AN ACC
PATHWAY,
SVT DURING ADMINISTRATION OF DRUGS
LIKE FLECAINIDE.
IN SVT WITH PRE-EXISTENT BBB.
CONCORDANT PATTERN
NEGATIVE CONCORDANCY VT
ARISING IN THE APICAL AREA
 POSITIVE CONCORDANCY  VT ARISING
IN THE LEFT POSTERIOR WALL OR
TACHYCARDIAS USING A LEFT
POSTERIOR ACC PATHWAY FOR AV
CONDUCTION
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TACHYCARDIA QRS MORE NARROW
THAN SINUS QRS
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NARROW QRS DURING TACHYCARDIA THAN
DURING SINUS RHYTHM 
VT ORIGIN CLOSE TO IVS
PRESENCE OF QR COMPLEXES

QR DURING WIDE QRS
TACHYCARDIA INDICATES A SCAR IN
THE MYOCARDIUM
 QR COMPLEX DURING VT IN 40%
OF VTs AFTER MI
RVOT VT
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IDIOPATHIC VT ARISING FROM RVOT
 3 PATTERNS.
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QRS AXIS + 70 AND LEAD 1 SHOWS A POSITIVE QRS
 ORIGIN OF VT IN THE LATERAL PART OF
RVOT
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INFERIOR QRS AXIS, QRS NEGATIVE IN LEAD 1 
VT ORIGIN ON THE SEPTAL SIDE IN THE RVOT
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INFERIOR QRS AXIS, NEGATIVE QRS IN LEAD 1 &
V1,V2 SHOWING INITIAL POSITIVITY OF THE QRS 
EPICARDIAL ORIGIN OF VT BETWEEN THE ROOT
OF THE AORTA AND THE POSTERIOR PART
OF THE RVOT .
IDIOPATHIC LEFT VT
LEFT AXIS DEVIATION  ORIGIN OF THE
VT IS IN OR CLOSE TO THE POSTERIOR
FASCICLE OF THE LBB
 FURTHER LEFTWARD QRS AXIS (NORTHWEST AXIS) ORIGIN OF VT MORE
ANTERIORLY CLOSE TO THE IVS
 INFERIOR QRS AXIS VT ORIGIN IN THE
ANTERIOR FASCICLE OF THE LBB
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ARVD
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3 PREDILECTION SITES IN THE RV
THE INFLOW
THE OUTFLOW
THE APEX
 LEFT AXIS DEVIATION IN A YOUNG
PERSON WITH LBBB SHAPED VT  ARVD
BBRT
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WHEN THE BROAD QRS IS IDENTICAL
DURING TACHYCARDIA AND SINUS
RHYTHM  BBRT OR SVT WITH PREEXISTENT BBB
 BBRT OCCUR IN PATIENTS WITH ASMI,
DCMY, MYOTONIC DYSTROPHY, AFTER
AORTIC VALVE SURGERY
VALUE OF ECG DURING SINUS
RHYTHM
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ECG DURING SINUS RHYTHM MAY SHOW PREEXISTENT BBB, VENTRICULAR PREEXCITATION OR AN OLD MI
 PRESENCE OF AV CONDUCTION
DISTURBANCES DURING SINUS RHYTHM 
VERY UNLIKELY THAT A BROAD QRS
TACHYCARDIA IN THAT PATIENT HAS A
SUPRAVENTRICULAR ORIGIN
Emergency Approach –
Wide QRS Tachycardia
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Do not panic when confronted with WCT
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Obtain a 12 Lead ECG
If Hemodynamically Unstable
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Carrdiovert
 Obtain a history
 Examine the pre and post cardioversion
ECG’S to determine the etiology of the
arrhythmia
If Hemodynamically Stable
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Examine the patient for clinical signs of
AVD
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Systematically evaluate the 12 Lead ECG
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Obtain a history
If Ventricular Tachycardia
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Give Procainamide 10mg/kg IV bolus over
5 minutes
 If Ischemia related – Give Lidocaine
 If unsuccessful, Cardiovert
 Examine the ECG during VT and during
sinus rhythm to determine the etiology of
the arrhythmia
If SVT with aberration
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Vagal stimulation. If unsuccessful,
 Adenosine 6 mg rapid IV bolus. If
unsuccessful,
 Give 12 mg rapid IV bolus. May be
repeated once. If unavailable ,
 Verapamil 10 mg IV over 3 minutes, reduce
to 5 mg if the patient is on beta blocker or
hypotensive. If unsuccessful,
 Procainamide 10 mg/kg IV over 5 minutes.
If unsuccessful,
 Cardiovert
Examine SVT and post- conversion ECG’s
to determine the mechanism
 If in doubt, do not give verapamil, give IV
Procainamide
 If irregular, Do not give AV nodal blocking
drugs like BB, CCB, Adenosine or Digitalis
 Give Procainamide IV or Amiodarone or
Propafenone
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Polymorphic VT with Normal QT
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Most frequently caused by Acute ischemia
or MI
 Poorly tolerated
 Tends to degenerate into VF quickly
 Rarely it is caused by ARVD, IPMVT (short
coupled variant of TDP) or familial
catecholaminergic PMVT
Polymorphic VT with long QT

Initiation of tachycardia is pause dependent
with late coupled PVC (long short initiating
sequence)
 Usually non sustained
 Syncope
 ECG abnormalities – Long QTc, abnormally
shaped T waves
Treatment
Sustained PMVT – unstable rhythm with
hemodynamic compromise and frequent
degeneration into VF
 Electrical cardioversion is the first line of therapy
to decrease the recurrence and as treatment for
NSPMVT
 BB recommended for PMVT with normal QT
 Magnesium for PMVT with long QT
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CONCLUSION
 WCT– VT MOST COMMON
 HISTORY IS IMPORTANT
 POST MI - WCT IS ALWAYS VT
UNLESS PROVED OTHERWISE
 PMVT WITH NORMAL QT - ACUTE
ISCHAEMIA
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