WIDE QRS TACHYCARDIA - WIDE QRS TACHYCARDIA - BEDSIDE DIAGNOSISBEDSIDE DIAGNOSIS
Dr.K.Chandrasekaran.MD.DM
Interventional cardiologist and
Cardiac Electrophysiologist
CLASSIFICATION OF TACHYCARDIAS CLASSIFICATION OF TACHYCARDIAS WITH A BROAD QRS COMPLEX 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
SVT WITH AV CONDUCTION OVER ACC SVT WITH AV CONDUCTION OVER ACC PATHWAYPATHWAY
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 TACHYCARDIAVENTRICULAR TACHYCARDIA
Regular SVT with BBB
VT
SVT with AV conductionOver accessory pathway
Irregular PMVT with NormalQT
AF
PMVT with long QT
BBB
Accessory Pathway
THE ECG DIAGNOSISTHE ECG DIAGNOSIS
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 A 47 year old man with a long history of palpitations and blackouts.palpitations and blackouts.
A 23 year old male with palpitationsA 23 year old male with palpitations
WIDTH OF QRS COMPLEXWIDTH 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.
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
WIDTH OF QRS COMPLEXWIDTH OF QRS COMPLEX
QRS AXIS IN THE FRONTAL PLANEQRS 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 CONFIGURATIONAL CHARACTERISTICS OF THE QRS COMPLEXTHE QRS COMPLEX
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
LBBB SHAPED VT V1,V2 SHOW INITIAL POSITIVE QRS ( r wave)> 30
mSecs, 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 CONFIGURATIONAL CHARACTERISTICS OF THE QRS COMPLEXTHE QRS COMPLEX
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
CONFIGURATIONAL CHARACTERISTICS CONFIGURATIONAL CHARACTERISTICS OF THE QRS COMPLEXOF THE QRS COMPLEX
INTERVAL ONSET QRS TO NADIR OF INTERVAL ONSET QRS TO NADIR OF
SWAVE IN PRECORDIAL LEADSSWAVE IN PRECORDIAL LEADS
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 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
TACHYCARDIA QRS MORE NARROW TACHYCARDIA QRS MORE NARROW THAN SINUS QRSTHAN SINUS QRS
NARROW QRS DURING TACHYCARDIA THAN DURING SINUS RHYTHM
VT ORIGIN CLOSE TO IVS
PRESENCE OF QR COMPLEXESPRESENCE 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 VTRVOT VT IDIOPATHIC VT ARISING FROM RVOT 3 PATTERNS. QRS AXIS + 70 AND LEAD 1 SHOWS A POSITIVE QRS
ORIGIN OF VT IN THE LATERAL PART OF
RVOT INFERIOR QRS AXIS, QRS NEGATIVE IN LEAD 1
VT ORIGIN ON THE SEPTAL SIDE IN THE RVOT 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 VTIDIOPATHIC LEFT VT
LEFT AXIS DEVIATION ORIGIN OF THE VT IS IN OR CLOSE TO THE POSTERIOR FASCICLE OF THE LBB
FURTHER LEFTWARD QRS AXIS (NORTH-WEST AXIS) ORIGIN OF VT MORE ANTERIORLY CLOSE TO THE IVS
INFERIOR QRS AXIS VT ORIGIN IN THE ANTERIOR FASCICLE OF THE LBB
ARVDARVD
3 PREDILECTION SITES IN THE RV
THE INFLOW
THE OUTFLOW
THE APEX LEFT AXIS DEVIATION IN A YOUNG
PERSON WITH LBBB SHAPED VT ARVD
BBRTBBRT
WHEN THE BROAD QRS IS IDENTICAL DURING TACHYCARDIA AND SINUS RHYTHM BBRT OR SVT WITH PRE-EXISTENT BBB
BBRT OCCUR IN PATIENTS WITH ASMI, DCMY, MYOTONIC DYSTROPHY, AFTER AORTIC VALVE SURGERY
VALUE OF ECG DURING SINUS VALUE OF ECG DURING SINUS RHYTHMRHYTHM
ECG DURING SINUS RHYTHM MAY SHOW PRE-EXISTENT BBB, VENTRICULAR PRE-EXCITATION 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 – Emergency Approach – Wide QRS TachycardiaWide QRS Tachycardia
Do not panic when confronted with WCT
Obtain a 12 Lead ECG
If Hemodynamically UnstableIf Hemodynamically Unstable
CarrdiovertObtain a historyExamine the pre and post cardioversion
ECG’S to determine the etiology of the arrhythmia
If Hemodynamically StableIf Hemodynamically Stable
Examine the patient for clinical signs of AVD
Systematically evaluate the 12 Lead ECG
Obtain a history
If Ventricular TachycardiaIf Ventricular Tachycardia
Give Procainamide 10mg/kg IV bolus over 5 minutes
If Ischemia related – Give LidocaineIf unsuccessful, CardiovertExamine the ECG during VT and during
sinus rhythm to determine the etiology of the arrhythmia
If SVT with aberrationIf SVT with aberration
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
Polymorphic VT with Normal QTPolymorphic VT with Normal QT
Most frequently caused by Acute ischemia or MI
Poorly toleratedTends to degenerate into VF quicklyRarely it is caused by ARVD, IPMVT
(short coupled variant of TDP) or familial catecholaminergic PMVT
Polymorphic VT with long QTPolymorphic VT with long QT
Initiation of tachycardia is pause dependent with late coupled PVC (long short initiating sequence)
Usually non sustainedSyncope ECG abnormalities – Long QTc,
abnormally shaped T waves
TreatmentTreatment
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
CONCLUSIONWCT– VT MOST COMMONHISTORY IS IMPORTANTPOST MI - WCT IS ALWAYS VT
UNLESS PROVED OTHERWISEPMVT WITH NORMAL QT - ACUTE
ISCHAEMIA
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