ECG

Question 1

Inferior leads

Answer 1

Lead II, III and aVF

Question 2

Lateral leads

Answer 2

V5, V6,
Lead I
aVR, aVL

Question 3

Anterior leads

Answer 3

V3, V4

Question 4

Leads giving septal view

Answer 4

V1, V2

Question 5

Course of electrical activity in the heart

Answer 5

Begins at sinoatrial node
Spreads to atrioventricular node
Through Bundle of His
To purkinje fibres
Causing ventricular contraction

Question 6

What deflection is produced when electrical activity moves in the direction of a lead?

Answer 6

Positive

Question 7

If the R wave is bigger than the S wave in which direction is depolarisation heading relative to the lead?

Answer 7

Towards the lead

Question 8

What term is used when Leads III and aVF are the most positive on ECG?

Answer 8

Right axis deviation

Question 9

What causes right axis deviation?

Answer 9

Right ventricular hypertrophy

Question 10

What conditions are associated with right axis deviation?

Answer 10

Pulmonary hypertension

May be normal in tall individuals

Question 11

What term is used for negative deflection in leads III and II?

Answer 11

Left axis deviation

Question 12

What leads to left axis deviation?

Answer 12

Conduction issues

Question 13

What is the normal cardiac axis?

Answer 13

Between -30 degrees and

+90 degrees

Question 14

What is a normal heart rate?

Answer 14

60-100bpm

Question 15

What heart rate indicated tachycardia?

Answer 15

Greater than 100 bpm

Question 16

What heart rate indicates bradycardia?

Answer 16

Less than 60 bpm

Question 17

How do you calculate the heart rate using ECG in a patient with regular heart rhythm?

Answer 17

Count number of large squares within one R-R interval

Divide 300 by number of large sqaures

Question 18

How do you calculate the heart rate on ECG in a patient with irregular heart rhythm?

Answer 18

Count number of complexes on rhythm strip and multiply by 6

Question 19

What condition is indicated by an irregularly irregular heart rhythm?

Answer 19

Atrial fibrillation

Question 20

What atrial activity is indicated by a sawtooth baseline?

Answer 20

Flutter waves

Question 21

What atrial activity is indicated by a chaotic baseline in absence of p waves?

Answer 21

Fibrillation

Question 22

What is the normal PR interval?

Answer 22

120-200 ms

3-5 small squares

Question 23

What is the value of a prolonged PR interval?

Answer 23

Greater than 0.2s

Question 24

What is indicated by a prolonged PR interval?

Answer 24

Atriventricular delay (AV block)

Question 25

A fixed prolonged PR interval indicates which type of heart block?

Answer 25

First degree

Question 26

What is seen on ECG in Mobitz Type I/Second degree type 1 / Wencheback phenomenon?

Answer 26

progressive prolongation of the PR interval until eventually the atrial impulse is not conducted and the QRS complex is dropped.

Question 27

What is seen on ECG in Mobitz type 2/ Second degree Type 2 AV block?

Answer 27

consistent PR interval duration with intermittently dropped QRS complexes due to a failure of conduction

Question 28

What is a 3:1 and 4:1 block?

Answer 28

Second degree AV block Type 2 Consistent prolonged PR, QRS complexes dropping intermittently 3: 1 = QRS dropping after every 3rd p wave 4: 1 = dropping after every 4th

Question 29

What are the typical ECG findings in 3rd degree heart block?

Answer 29

No association between P waves and QRS complexes | Narrow and broad complexes

Question 30

Where do narrow complexes fire from in 3rd degree heart block?

Answer 30

Above the bifurcation of the bundle of His

Question 31

Where do broad complexes originate in 3rd degree heart block?

Answer 31

Below the bifurcation of the bundle of His

Question 32

What condition presents on ECG with a slurrede upstroke of the QRS complex and shortened PR interval?

Answer 32

Wolff parkinson White syndrome | Delta wave - bunny ears

Question 33

What is indicated by a tall QRS complex?

Answer 33

Ventricular hypertrophy

Question 34

What is required to diagnose Wolff parkinson white?

Answer 34

Delta wave AND tachyarrythmias

Question 35

Define a pathological Q wave

Answer 35

> 25% the size of the R wave that follows it or > 2mm in height and > 40ms in width.

Question 36

What are Q waves indicative of if found with inverted t waves in a territory?

Answer 36

Previous MI

Question 37

ST elevation indicates?

Answer 37

MI

Question 38

ST depression indicates?

Answer 38

Myocardial ischaemia

Question 39

Tall T waves are associated with?

Answer 39

Hyperkalaemia | Hyperacute STEMI

Question 40

Causes of inverted T wave

Answer 40

Ischaemia Bundle branch blocks (V4-6 in LBBB and V1-V3 in RBBB) Pulmonary embolism Left ventricular hypertrophy (in the lateral leads) Hypertrophic cardiomyopathy (widespread) General illness

Question 41

Biphasic T waves indicate

Answer 41

Ischaemia | Hypokalaemia

Question 42

Flattened T waves indicate?

Answer 42

Ischaemia | Electrolyte imbalance

Question 43

What is a U wave?

Answer 43

Deflection not often seen after the T wave | Best seen in V2 or V3

Question 44

What can a U wave indicate?

Answer 44

electrolyte imbalances, hypothermia and secondary to antiarrhythmic therapy (such as digoxin, procainamide or amiodarone).

Question 45

Which antiarrhythmic drugs can cause a U wave on ECG?

Answer 45

Digoxin Procainamide Amiodarone