ECG Interpretation

List the Five Step Method in order:

Regularity

Rate

P Waves

PR Interval

QRS Complex

Sinus Rhythm

Sinus Bradycardia

Sinus Tachycardia

Sinus Arrhythmia

Ventricular Tachycardia

Ventricular Fibrillation - Medium Coarse

Ventricular Fibrillation - Coarse

Ventricular Fibrillation - Fine

Asystole

Pulseless Electrical Activity (PEA)

Torsades de Pointes

Atrial Fibrillation

Atrial Flutter

Premature Atrial Contraction (PAC)

Supraventricular Tachycardia (SVT)

Junctional Escape Rhythm

Accelerated Junctional Rhythm

Junctional Tachycardia

Premature Junctional Contraction (PJC)

Idioventricular & Accelerated Idioventricular Rhythm

Premature Ventricular Contraction (PVC)

Unifocal PVC

Multifocal PVC

Unifocal/Multifocal PVC Couplet

Ventricular Bigeminy PVC

Ventricular Trigeminy PVC

Ventricular Quadrigeminy PVC

Non-sustained VT

R-on-T PVC

1st Degree Heart Block

2nd Degree Heart Block Type 1

2nd Degree Heart Block Type 2

2nd Degree Heart Block with 2:1 AV Block

3rd Degree Heart Block

Ventricular Pacemaker

Atrial Pacemaker

Dual Chamber Pacemaker

Failure to Capture - Ventricles

Failure to Capture - Asystole

Undersensing

Sinus Block - Pause

Sinus Arrest

ST Depression

ST Elevation

Inverted T Wave

Widened QRS

What is Step 1 of the Five Step Method?

Regularity

What is Step 2 of the Five Step Method?

Rate

What is Step 3 of the Five Step Method?

P Waves

What is Step 4 of the Five Step Method?

PR Interval

What is Step 5 of the Five Step Method?

QRS Complex

Five Step Method - Step 1: Regularity

- Is the rhythm regular of irregular?

- Are there any patterns to the regularity?

- Are there any ectopic beats, if so are they early or late?

Five Step Method - Step 2: Rate

- What is the exact rate?

- Is the atrial rate the same as the ventricular rate?

Which methods can be used to determine the Rate?

Second Strip Method

Triplicate Method

R-R Interval, including 60, 300 and 1500 Methods

Second Strip Method

Triplicate Method

R-R Interval: 300 Method

R-R Interval: 1500 Method

PQRST-U Complex

Flat Line

Isoelectric line with no electrical activity

Positive Isoelectric Line

Positive charge to positive lead

Negative Isoelectric Line

Negative charge to negative lead

P Wave: Impulse initiated in the SA Node

Depolarisation of the atria begins

P Wave: Beginning of Atrial Excitation

Atrial depolarisation proceeds from right, through the internodal tracts to left through Bachmann's bundle

P Wave: Atrial Excitation

Atrial contraction occurs

P-R Interval

Impulse reaches the AV Node

Impulse delay at AV Junction

QRS Complex

Depolarisation of the ventricles through the Bundle of His, Left and Right Bundle Branches and Purkinje Fibres

T Wave

Ventricular repolarisation occurs

Electrical charge in the pacemaker and myocyte cells return to polarised state with sodium outside and potassium inside the cell

Five Step Method - Step 3: P Waves

- Are the P waves regular?

- Is there one P wave for each QRS complex?

- Is the P wave in front of the QRS or behind it?

- Is the P wave normal and upright in Lead II?

- Are there more P waves than QRS complexes?

- Do all the P waves look alike?

- Are the irregular P waves associated with ectopic

beats?

Five Step Method - Step 4: P-R Interval

- Is the PR interval measurement within normal

range? (Normally 0.12 to 0.20 seconds/3 to 5 small squares)

- Are the PRIs constant?

- If the PR interval varies, is there a pattern to the

changing measurements?

Five Step Method - Step 5: QRS Complex

- What is the width of the QRS complex? (Normally < 0.12 seconds)

- Are the QRS complexes within normal limits?

- Are all the QRS complexes of equal duration?

- Do all QRS complexes look alike?

- Are the unusual QRS complexes associated with ectopic beats?

The Cardiac Cycle - Step 1

Depolarisation wave travels from the SA node down Bachmann's bundle to the left artia and down the internodal tracts to the right atria

The Cardiac Cycle - Step 2

Right and Left Atria contract together

Pressure of contraction produces closure of the aortic and pulmonary semilunar valves

The Cardiac Cycle - Step 3

Atrial contraction pumps blood through the tricuspid and mitral atrioventricular valves into the left and right ventricles

The Cardiac Cycle - Step 4

Depolarisation wave from the SA node reaches the AV node with a 0.1 second delay before the AV node fires

The Cardiac Cycle - Step 5

Depolarisation wave travels from the AV node through the Bundle of His, down the left and right bundle branches and into the Purkinje fibres

The Cardiac Cycle - Step 6

Right and Left Ventricles contract together

Pressure of contraction produces closure of the tricuspid and mitral atrioventricular valves

The Cardiac Cycle - Step 7

Ventricular contraction pumps blood through the aortic valve into the systemic circulation and through the pulmonary valve into the lungs

The Cardiac Cycle - Step 8

Ventricular repolarisation occurs

Pacemaker Cells

Make up the electrical conduction system of the heart, including the Sinoatrial node, Bachmann's bundle, internodal tracts, Atrioventricular node, Bundle of His, left bundle branch, left posterior fascicle, left anterior fascicle, right bundle branch and Purkinje fibres

Cardiac Myocytes

Work in functional syncytium with pacemaker cells and are responsible for the mechanical contraction of cardiac muscle

Depolarisation & Repolarisation: Pacemaker Cells

Depolarisation & Repolarisation: Cardiac Myocytes

Sinus Rhythm - Interpretation Example

Sinus Bradycardia - Interpretation Example

Sinus Tachycardia - Interpretation Example

Sinus Arrhythmia - Interpretation Example

What are the four types of Sinus Rhythms?

Sinus Rhythm

Sinus Bradycardia

Sinus Tachycardia

Sinus Arrhythmia

What are the four types of 'Arrest' Rhythms?

Ventricular Tachycardia

Ventricular Fibrillation

Asystole

Pulseless Electrical Activity

Ventricular Tachycardia - Interpretation Example

What is the Dominant Pacemaker?

Sinoatrial node

What are the Escape Pacemakers?

AV node

Bundle of His

Bundle branches

Purkinje fibres

What is the AV Junction?

Anatomical location of the AV node and Bundle of His

What is the Intrinsic Rate of the SA Node?

60-100BPM

What is the Intrinsic Rate of the AV Junction?

40-60BPM

What is the Intrinsic Rate of the Bundle Branches?

30-40BPM

What is the Intrinsic Rate of the Purkinje Network?

20-40BPM

Intrinsic Rate