ECG

Question 1

What 2 possible diagnoses could it be in someone with a broad complex tachycardia with no P waves?

Answer 1

VF/ VT

Question 2

A patient has a narrow complex tachycardia with abnormal/absent p waves and irregular rhythm - diagnosis?

Answer 2

AF

Question 3

A patient has a narrow complex tachycardia with abnormal/absent p waves and regular rhythm - what are the 3 diagnoses it may be? Which one is most likely?

Answer 3

Atrial flutter; SVT; atrial tachycardia

SVT until proven otherwise

Question 4

What is another name for ‘left anterior fascicular block’? How would this show on ECG?

Answer 4

Left anterior hemiblock

Left axis deviation

Question 5

What is blocked in a bifascicular block?

Answer 5

Right bundle branch and left anterior fascicle are blocked

Question 6

How does a bifascicular block present?

Answer 6

Left axis deviation

Question 7

Name some of the main causes of a bifascicular block

Answer 7

IHD, HTN, AS, anterior MI, congenital heart disease hyperkalaemia

Question 8

What would you call a bifid p wave? What pathology does it suggest? Which part of an ECG would you most commonly see it?

Answer 8

P mitrale
Suggests left atrial hypertrophy e.g. caused by MS
Most common in V1

Question 9

What is the name for a peaked p wave? What pathology does it suggest?

Answer 9

P pulmonale.

Suggests right atrial hypertrophy

Question 10

Define PR interval

Answer 10

Start of p wave to start of Q wave

Question 11

Define PR segment

Answer 11

End of p wave to start of Q wave

Question 12

What does the PR interval represent?

Answer 12

Conduction through the AV node

Question 13

Name 3 ECG changes you may see in someone with WPW?

Answer 13

• Short PR interval
• Broad QRS
• Slurred upstroke to the QRS complex (the delta wave)

Question 14

What 3 treatments should you give to a patient who is stable with broad complex tachycardia?

Answer 14

Amiodarone
Class 1 antiarrhythmics
Beta-blockers e.g. metaprolol

Question 15

What is the treatment for SVT?

Answer 15

Valsalva manoeuvre then adenosine

Question 16

What is the pathophysiology behind atrial flutter?

Answer 16

Electrical conduction which goes backwards in the right atria due to a re-entry circuit in RA - the AVN passes some of these impulses on

Question 17

A patient has large R waves in V5/V6 (>5 large squares) - what does this suggest?

Answer 17

Left ventricular hypertrophy

Question 18

What does a dominant R wave in V1 suggest?

Answer 18

Right ventricular hypertrophy

Question 19

Define the QT interval

Answer 19

Start of Q wave to end of T wave

Question 20

Why is a prolonged QT wave dangerous?

Answer 20

Increases risk of ventricular arrhythmias, especially Torsades de pointes which can lead to VF

Question 21

Define ST segment

Answer 21

End of S wave to beginning of T wave

Question 22

What ECG change is seen in Digoxin toxicity?

Answer 22

Downward sloping/ ‘reverse tick’ ST segment

Question 23

Name 2 times when someone might have biphasic T waves

Answer 23

MI or hypokalaemia

Question 24

Define a U wave. Where on an ECG is it best seen?

Answer 24

> 0.5 mm deflection after the T wave. Best seen in V2 or V3

Question 25

Name something that might cause U waves

Answer 25

Hypokalaemia

Question 26

Name (9) causes of a prolonged QT

Answer 26

``` Hypokalaemia Hypomagnesaemia Post-cardial arrest Congenital long QT syndrome Hypocalcaemia Hypothermia MI Drugs ```

Question 27

What is Brugada syndrome?

Answer 27

Cardiac sodium channelopathy

Question 28

What 2 ECG changes are seen in someone with Brugada syndrome?

Answer 28

RBBB w/ ST elevation V1 - 3

Question 29

Talk through the changes you would see in someone who has experienced an acute MI

Answer 29

Hyperacute T waves persists for a few mins | ST elevation, T wave inversion (within 24 hours), pathological Q waves

Question 30

When would you see pathological Q waves?

Answer 30

Full thickness MI | Develops 8-12 hours after ST elevation if myocardium not reperfused

Question 31

What is the criteria to diagnose a STEMI?

Answer 31

ST elevation in >2 small squares in 2 adjacent chest leads or ST elevation >1 small square in 2 adjacent limb leads OR new LBBB

Question 32

What 2 things may you seen on an ecg of someone with hypertrophic cardiomyopathy?

Answer 32

Left ventricular hypertrophy signs + dramatic T wave inversion in lateral leads

Question 33

Name 2 changes you might see on the ecg of someone with myocardial ischaemia

Answer 33

ST depression and new T wave inversion (but hyperacute T waves may be the first ecg change you notice)

Question 34

What 2 signs on an ecg would suggest that someone has had a previous infarct?

Answer 34

T wave inversion and pathological Q waves

Question 35

What would happen to the following in hyperkalaemia... - P waves - QRS - ST segment - T waves

Answer 35

- Low flat P waves - Wide bizarre QRS - Slurring into the ST segment - Tall tented T waves

Question 36

``` What would happen to the following in hypokalaemia... - T waves - PR - ST segment Which abnormal wave may appear? ```

Answer 36

- Small flattened T wave - Prolonged PR - Depressed ST - Prominent U wave

Question 37

What would happen to the QT interval in hypercalcaemia?

Answer 37

Short QT

Question 38

What would happen to the QT interval in hypocalcaemia?

Answer 38

Prolonged QT

Question 39

What are the 'classic' ECG changes seen in someone with a PE?

Answer 39

S1Q3T3 | Large S wave in lead I, large Q wave in lead III, inverted T wave in lead III

Question 40

What 3 ecg changes are you likely to find in someone with a PE?

Answer 40

RBBB + right axis deviation + sinus tachycardia

Question 41

What would happen to the R waves in a posterior MI? Where on the ecg would this be best seen?

Answer 41

Tall R waves in V1 + V2

Question 42

Which 2 changes would you see on the ecg of someone with pericarditis? Which one is most specific?

Answer 42

``` Saddle-shaped ST interval PR depression (specific) ```