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

THANK YOUTHANK YOU