Dr. Shankar Hippargi Dr. Shankar Hippargi ConsultantConsultant

Dept. of Accident & Emergency MedicineDept. of Accident & Emergency Medicine

Life threatening cardiac arrhythmias- Restoring life

Objectives

• To identify and treat• Tachycardias• Premature ventricular contractions• AV blocks (bradycardias)

Normal conduction

Tachycardia

• Narrow complex– Sinus tachycardia– Atrial fibrillation– Atrial flutter– Multifocal atrial

tachycardia– Re-entry tachycardia

(SVT)

• Broad complex– Ventricular tachycardia– Ventricular fibrillation– Torsades de pointes

Sinus tachycardia

• Regular • Narrow QRS• Always secondary to some cause (anxiety, pain,

hypovolumia, fever etc.)• Identify and treat the cause

Atrial fibrillation

• Irregularly irregular• Atrial rate >400, ventricular rate

170-180/min• Narrow QRS complex• No definite P waves• No isoelectric line

• If acute or patient is unstable do synchronized cardioversion with 50J

• Control ventricular rate with Diltiazem 0.25mg/kg, Verapamil 5mg, Metaprolol 25mg, Digoxin 0.5mg

• If >2 days (onset not known) do ECHO to R/O thrombus in atrium

• If no clot Cardioversion with 50J• If there is a clot anti coagulate for 1-3

weeks

Atrial Fibrillation- Treatment

Atrial flutter

Regular

Atrial rate 250-350/min

Flutter waves (saw tooth appearance)

AV block (2:1, 3:1)

Atrial flutter

• This may progress into atrial fibrillation

• Treatment is similar to atrial fibrillation

Multifocal atrial tachycardia (MAT)

Multifocal atrial tachycardia (MAT)• Wandering pacemaker• Irregularly irregular• Each P-wave is different in morphology• Narrow QRS complex• Standard anti arrhythmic agents ineffective• Cardioversion has no effect• Magnesium sulfate 2gm iv over 1 min, and

infusion at 1-2gm/hr• Maintain K+ level above 4mEq/lt• Verapamil 5-10mg to control ventricular rate

Re-entry tachycardia (SVT)

Re-entry tachycardia (SVT)

• Regular • Narrow QRS• Rate > 150/min• P waves will be either

absent, inverted, or seen after QRS

Re-entry tachycardia (SVT)

• Carotid massage 10 sec (caution)• Valsalva maneuver• Facial immersion in cold water 6-7 sec• Adenosine 6mg rapid IV push (ultra short

acting), repeat dose 12mg• Verapamil 5mg slow IV• Diltiazem 0.25mg/kg slow IV• Synchronized cardioversion with 50J

Monomorphic VT

Monomorphic VT

• More than 3 consecutive PVC • Regular• Rate >100/min• Broad QRS complex (>3 small squares)• Each QRS similar in shape

Monomorphic VT

• If unstable (pulseless)– Start CPR, defibrillate with 200J

biphasic or 360J monophasic, resume CPR for 2 min, reassess the rhythm

– Adrenaline 1mg, Amiodarone 300mg or Lidocaine 50-75mg and re attempt defibrillation

– Defibrillation can be continued as long as there is shockable rhythm

A&E(SRMC)

Monomorphic VT

• Stable VT (with pulse)– Amiodarone 150mg slow iv over 10min,

followed by infusion at 1mg/min for 6 hours and 0.5mg/min for next 18 hours

– Alternatively Lidocaine 1-1.5mg/kg bolus and infusion at 1-4mg/min

– Synchronized Cardioversion with 100J

Polymorphic VT

Polymorphic VT

• Irregularly irregular

• QRS wide

• Each QRS different from others

• May progress to VF

• Treatment same as VF

Torsades de pointes

• Twisting of points

• Special variant of polymorphic VT

• Magnesium sulfate 2gm in 10ml DNS over 2-3 min, followed by infusion at 1-2gm/hr

• Temporary pacing may abolish TdP

A&E(SRMC)

Ventricular fibrillation

Coarse VfibCoarse Vfib

Fine Vfib

Ventricular fibrillation

• Irregularly irregular

• Wide and varying QRS

• Disorganized

• Incompatible with life (cannot produce CO)

• Its important to differentiate fine Vfib from asystole

Ventricular fibrillation

• Start CPR immediately, shock with 200J biphasic or 360J monophasic

• Resume CPR for 2 min (don’t look at monitor)

• Adrenaline 1mg, Amiodarone 300mg or Lidocaine 75mg

• Assess rhythm, if Vfib persists shock and resume CPR for 2 min (repeat the cycle)

Premature ventricular contractions

• Occasional PVC

• Bigeminy

• Trigeminy

• Couplet

• Triplet

OccasionalOccasional PVCPVC

Bigeminy

Trigeminy

Couplet

Triplet

AV blocks

• First degree AV block

• Second degree AV block– Mobitz type 1 (Wenckebach)– Mobitz type 2

• Third degree AV block (complete heart block)

First degree AV block

• Regular

• Prolonged PR interval (>5 small squares)

• Narrow QRS

• No treatment required

• Regular

• Prolonged PR interval (>5 small squares)

• Narrow QRS

• No treatment required

Second degree Type 1(wenckebach)

• Regularly Irregular• Progressively increasing PR interval until 1 QRS

is dropped, and the cycle repeats• QRS narrow• Reversible • No treatment if asymptomatic• If symptomatic give atropine 0.5mg, repeat every

3 min (max 3mg)• Temporary pacing

Second degree Type 2

• Irregularly irregularly• Constant PR interval, narrow/wide QRS• QRS dropped irregularly• Irreversible • May progress to complete block• Atropine 0.5mg repeated every 3min (max 3mg),

may not be effective• Permanent pacing

Third degree (complete) AV block

• Regular P-P interval and R-R interval

• More P waves than QRS

• QRS usually wide, but may be narrow

• Atropine not effective

• Permanent pacing