ARRHYTHMIA DR MANSOUR ALQURASHI Associate professor of Clinical Pediatrics College of Medicine, Imam University, Riyadh.

Objectives At the end of this session students should be able to: Distinguish the normal from abnormal rhythms. Understand the pathophysiologic basis of arrhythmia. Differentiate ventricular from supraventricular arrhythmias. Recognize different types of supraventricular arrhythmias. Recognize the different types of heart block. Be familiar with strategies of arrhythmia management.

Conduction system hierarchy

Basic ECG elements ST interval TP segment T wave QT interval ST segment QRS PR interval PR segment P wave Duration Intervals Joining Segments Basic elements

2 dimensions P Q R S T Time Axis

Classification of arrhythmia Variable Classes Rate Tachycardia Bradycardia Morphology Narrow complex Wide complex Origin Supra-ventricular Junctional Ventricular Mechanism Reentrant Automatic Triggered P-QRS relationship 1st degree AV block 2nd degree AV block 3rd degree AV block

Mechanisms of arrhythmia Enhanced automaticity Reentry Triggered activity

Reentry macro & micro reentry functional or structural

Rhythm analysis (P-QRS) (P waves & QRS) Present Sinus / non sinus Absent Real / technical Rate Slow Appropriate/inappropriate Fast Narrow/wide complex Regularity Regular Irregular Group beating or haphazard P wave morphology & QRS morphology Axis up/down P waves, extreme axis Duration & Axis Normal or wide (RBBB, LBBB), sup. axis P-QRS relationship Normal 1:1, normal PR interval Abnormal Ratio, duration (fixed, variable, unrelated) Others PR & QT intervals Long or short

Normal sinus rhythm

Normal Sinus Rhythm

Sinus Tachycardia (Appropriate vs inappropriate)

Sinus Tachycardia

Sinus Bradycardia (Appropriate vs inappropriate)

Sinus Bradycardia

Sinus Arrhythmia (normal or abnormal?)

Sinus Arrhythmia

What is the abnormality ?

Atrial Flutter

Atrial Flutter

Atrial Fibrillation

Atrial Fibrillation

Paroxysmal supra- ventricular tachycardia (AV nodal reentrant tachycardia)

Paroxysmal supra- ventricular tachycardia (AV nodal reentrant tachycardia)

Paroxismal SVT (AVNRT)

Clinical Signs of Tachyarrhythmia

1st degree AV block

1st degree AV block

Type I second degree AV block

2 nd Degree Block Type 1

Type II second degree AV block

Second degree AV block (type- II)

Complete Heart Block (third degree AV block)

Complete heart block

What do you notice?

Non-sustained VT

Ventriculat tachycardia Why? P P P P

Monomorphic VT What is the mechanism?

Polymorphic VT What is the mechanism?

Ventricular fibrillation

Ventricular fibrillation

Asystole

Case Study 5

Long QT syndrome (Jervell-Nielson-Lange) QT (corrected) QTc= QT (msec) √R-R (sec) = 640/ 1.05 = 610 msec > 450 m sec is long

WPW

Arrhythmia management Aim: Hemodynamic stability Prevent complications Symptomatic relief Strategies: Restoration of normal rhythm Slowing of tachyarrhythmia Augmenting the slow rhythm Options: Pharmacological agents Electrical cardioversion Transcatheter ablation Device implantation Emergency versus elective management Electrophysiology lab

Emergency cardioversion

وَفِي أَنفُسِكُمْ أَفَلَا تُبْصِرُونَ