Arrhythmias – clinical features

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Transcript of Arrhythmias – clinical features

Arrhythmias: Bland & the Nasty

Approach to Childhood Arrhythmias

• Tachyarrhythmias– Classification– Diagnostic approach– Immediate treatment strategies

Long term management of tachyarrhythmias

Bradyarrhythmias

Arrhythmias: Bland & the Nasty

Classification of tachycardia

• conventional SVT / VT

• electrophysiological re-entry / automatic• appearance normal QRS / wide QRS

• age infancy / childhood• behaviour paroxysmal / incessant

• structural normal / post-op

• significanceBland / nasty

• substrate e.g. accessory connection

• Mechanism e.g. orthodromic AV re-entry

Non invasive diagnosis of tachycardia

Arrhythmias: Bland & the Nasty

Typical responses!

Panic is an unnecessary and inappropriate response because most childhood arrhythmias are associated

with stable hemodynamics

Arrhythmias: Bland & the Nasty

Arrhythmia Management: Basic Rule

• Diagnosis before treatment • A variety of incorrect practices in

management of arrhythmias result from a failure to respect this simple rule

Unless it is an emergency resist the urge to treat the arrhythmia before being sure what it is!

Arrhythmias: Bland & the Nasty

Diagnostic Approach for Tachyarrhythmias

Traditional Classification

Narrow QRS

Usually stable hemodynamics

Supraventricular

Broad QRS

Often unstable hemodynamics

Ventricular /supraventricular

Arrhythmias: Bland & the Nasty

1 : 1 A V B

r e g u l a r i r r e g u l a r

n o r m a l Q R S

L B B B R B B B n e i t h e r

r e g u l a r i r r e g u l a r

w i d e Q R S

t a c h y c a r d i a

Diagnosis of tachycardia

Classification of tachycardia

Arrhythmias: Bland & the Nasty

Diagnosis of tachycardia

essential information

• history - age of onset, symptoms, etc• ECG in tachycardia• ECG in sinus rhythm

• ECG with adenosine administration

Arrhythmias: Bland & the Nasty

Irregular heart beatInappropriate heart rate for the situationUnexplained CHFDiseases associated with arrhythmiasSyncope/palpitationsFamily history

Arrhythmias – clinical features

Arrhythmias: Bland & the Nasty

Arrhythmias: The First Step

• Connect the child to an ECG machine

• Get a 12 lead ECG

• If the child is uncooperative, at least get the limb leads

Arrhythmias: Bland & the Nasty

The Monitor Can Mislead

• Single non-standard lead• P waves are not often clearly seen

• Interpretation of QRS morphology• Regular vs. Irregular rhythm• Difficult to document response to

intervention

Arrhythmias: Bland & the Nasty

ECG analysis - normal QRS

• are the QRS complexes regular?• are P waves seen?• what is the AV or VA relationship?• where is the P wave in the RR interval?

Non invasive diagnosis of tachycardia

Arrhythmias: Bland & the Nasty

Narrow QRS Tachycardia

Irregular• Atrial fibrillation• Multifocal or chaotic

atrial tachycardia• Flutter with varying

conduction

Regular• Sinus tachycardia• Atrial Flutter• AV nodal re-entrant

tachycardia• Tachycardias based

on bypass tracts

•Ectopic atrial tachycardia•Junctional ectopic tachycardia

Arrhythmias: Bland & the Nasty

Arrhythmias: Bland & the Nasty

Irregular Narrow QRS Tachycardia

Arrhythmias: Bland & the Nasty

Fast AF in patient with ASD

Arrhythmias: Bland & the Nasty

Irregular Narrow QRS Tachycardia

MAT

Ectopic atrial tachycardia

A Flutter with varying conduction

Arrhythmias: Bland & the Nasty

P wave morphology

I

II

III

Arrhythmias: Bland & the Nasty

12 Lead ECG: P-QRS Relationship

A-V dissociation: JET

Arrhythmias: Bland & the Nasty

Sinus Tachycardia

Arrhythmias: Bland & the Nasty

Sinus Tachycardia: A Cause Can Almost Always be Found

• Anxiety

• Fever

• Hypovolemia

• Hyperthyroidism

• Bronchodilators

Arrhythmias: Bland & the Nasty

Sinus Tachycardia: In the ICU

• “Light” sedation

• Inotropes and chronotropes

• Low output

• Fever (rectal temp)

• Hypovolemia

Arrhythmias: Bland & the Nasty

Sinus Tachycardia

• Rates can be as high as 240/min

• Subtle variations in rate

• Treating cause brings down the rate

• When in doubt: 12 lead ECG

• If doubts persist: adenosine

Arrhythmias: Bland & the Nasty

Narrow QRS Tachycardia: P Waves are not always Seen…..

Arrhythmias: Bland & the Nasty

Diagnosis of tachycardia

Recording response to adenosine

•Ultra short acting

•Blocks conduction across the AV node

•Terminates tachyarrhythmias where AV node is a part of the circuit

•Temporarily slows heart rates if circuit above AV node

Arrhythmias: Bland & the Nasty

Administering Adenosine

Adenosine 50-200 mcg/kg, fast push

Saline bolus, fast push

Reliable proximal IV line

10 cm extn.

Arrhythmias: Bland & the Nasty

Arrhythmias: Bland & the Nasty

Stable Narrow QRS tachycardiaAdenosine 140 mcg/kg bolus

Sudden termination

AVNRTAVRT

Slow and unmask

Flutter,ectopic atrial

tachy

No effect

Sinus tachy,Junctional ectopic

tachycardia

Arrhythmias: Bland & the Nasty

AV nodal re-entrant tachycardia: Sudden termination with adenosine

Response to Adenosine

Tachycardia Sinus

Arrhythmias: Bland & the Nasty

Response to Adenosine

Tachyarrhythmia after Senning + Rastelli (LTGA, VSD, PS)

Surface

Atrial

Atrial

Abrupt restoration to Sinus Rhythm after adenosine

Arrhythmias: Bland & the Nasty

Response to Adenosine

Narrow QRS tachycardia @ 200/min

Unmasking of atrial activity (Flutter waves)

Arrhythmias: Bland & the Nasty

Alternatives to Adenosine

• Ice bag on face; effects similar to adenosine• Older children and teens:

– Carotid sinus massage, supine valsalva

– Verapamil 0.1 mg / kg slow (only for narrow QRS tachycardias

• Cardioversion: Synchronized DC shock - 0.5 – 1 J/kg. First line for unstable narrow QRS tachycardia

Arrhythmias: Bland & the Nasty

Response to DC Shock

Responders: all re-entrant arrhythmias

A Flutter, AVRT, AVNRT, reentrant VT

Non-responders: all tachycardias based on automatic foci

JET, EAT, Sinus tachycardia, MAT

Arrhythmias: Bland & the Nasty

After the Event: ECG in Sinus Rhythm

Arrhythmias: Bland & the Nasty

Failure of the tachycardia to terminate after adenosine

Cardioversion

Ectopic atrial Tachycardia

Flutter

Sinus Tachycardia

Beta BlockadeDigoxin

Amiodarone

Digoxin, Betablockade

Rarely Amiodarone

Treat the Cause

Arrhythmias: Bland & the Nasty

Tachycardiomyopathy

• Certain incessant tachycardia in children can present clinically with heart failure and LV dysfunction like “myocarditis or DCM”

• Permanent Junctional Re-entrant tachycardia: RF ablation

• Ectopic atrial tachycardia: Antiarrhythmic medications / RF ablation

Arrhythmias: Bland & the Nasty

ECG analysis - wide QRS

• what is the QRS morphology in sinus rhythm?• is the QRS pattern LBBB, RBBB, pre-excited,

other?• are the QRS complexes regular?• are P waves seen?• what is the AV / VA relationship?

Non invasive diagnosis of tachycardia

Arrhythmias: Bland & the Nasty

Arrhythmias: Bland & the Nasty

Arrhythmias: Bland & the Nasty

Arrhythmias: Bland & the Nasty

Arrhythmias: Bland & the Nasty

TORSADES DE POINTES

Arrhythmias: Bland & the Nasty

Wide QRS tachycardia

Stable Unstable

DC shockIf 1:1 P-QRS relation, try adenosine

If AV dissociation, IV Lignocaine 1 mg/kg or IV amiodarone 5 mg/kgIf no response, DC shock CPR

Arrhythmias: Bland & the Nasty

Unstable Wide QRS Tacharrhythmia

• VT• Synchronized DC

shock 0.5-2 J/kg

• VF• Unsynchronized

DC shock 2-4 J/kg

Arrhythmias: Bland & the Nasty

ECG After the Event……..

Long QT syndrome

Arrhythmias: Bland & the Nasty