ECGs

Question 1

How do you calculate rate on a regular ECG?

Answer 1

300 / (number of large boxes between two R waves)

Question 2

How do you calculate rate on a tachycardic ECG?

Answer 2

1500 / (number of small boxes between two R waves)

Question 3

How do you calculate rate on an irregular ECG?

Answer 3

(number of QRS complexes in 6 seconds (30 large boxes)) x 10

Question 4

Which two leads do you look at to determine the heart axis?

Answer 4

Lead I and aVF

Question 5

Which leads will be positive/negative in a normal axis?

Answer 5

I = +ve, aVF = +ve

Question 6

Which leads will be positive/negative in right axis deviation?

Answer 6

I = -ve, aVF = +ve

Question 7

Which leads will be positive/negative in left axis deviation?

Answer 7

I = +ve, aVF = -ve

Question 8

What is a normal PR interval?

Answer 8

120-200ms (3-5 small squares)

Question 9

What is a normal QRS duration?

Answer 9

<120ms (<3 small squares)

Question 10

In which leads should p waves be upright and rounded?

Answer 10

II, III and aVF

Question 11

What do most supra ventricular rhythms have in common?

Answer 11

Narrow QRS

Question 12

What are three main criteria for sinus rhythm?

Answer 12

1. P wave for every QRS 2. QRS for every P wave 3. PR interval <200

Question 13

What is the difference between sinus rhythm and a sinus arrhythmia?

Answer 13

The rhythm itself in a sinus arrhythmia is irregular

Question 14

What is the most common cause of sinus arrhythmia?

Answer 14

Breathing - physiological

Question 15

What are the three main criteria for AF?

Answer 15

1. No visible P waves 2. Irregularly irregular QRS 3. Ragged baseline

Question 16

In atrial flutter, what is the atrial contraction rate?

Answer 16

300bpm

Question 17

What is the characteristic finding on an atrial flutter ECG?

Answer 17

Sawtooth baseline

Question 18

What is the name given to the repeated p waves found in atrial flutter?

Answer 18

f waves

Question 19

What is a supraventricular tachycardia?

Answer 19

Regular, tachycardic rhythm often with no clear P waves

Question 20

What are the three main types of SVT?

Answer 20

1. Atrioventricular nodal re-entrant tachycardia (AVNRT) 2.Atrioventricular re-entrant tachycardia (AVRT) 3. Atrial tachycardia

Question 21

What is the pathophysiology of SVTs?

Answer 21

Re-entry of an electrical signal to the atria

Question 22

What is the accessory pathway called in Wolff-Parkinson White Syndrome?

Answer 22

Bundle of Kent

Question 23

What are the three characteristic features of a WPW ECG?

Answer 23

1. Short PR interval 2. Wide QRS 3. Delta wave

Question 24

What do all ventricular rhythms have in common?

Answer 24

Broad QRS

Question 25

What are ventricular ectopics?

Answer 25

Premature ventricular beats

Question 26

Are ventricular ectopics pathological?

Answer 26

Not always

Question 27

Is monomorphic VT pathological?

Answer 27

Always

Question 28

What is the appearance of polymorphic VT?

Answer 28

Forth Rail Bridge

Question 29

What do QRS complexes look like in Torsades de Pointes?

Answer 29

Increasing and decreasing in height

Question 30

What are the two rhythms that Torsades de Pointes may progress to?

Answer 30

1. Sinus rhythm 2. VT

Question 31

What is VF always associated with?

Answer 31

Loss of consciousness

Question 32

Describe a VF ECG.

Answer 32

Irregular and random baseline with no clear waveforms

Question 33

What two beats are almost always diagnostic of VT?

Answer 33

1. Capture 2. Fusion

Question 34

What does this ECG show?

Answer 34

AF

Question 35

What does this ECG show?

Answer 35

AF

Question 36

What does this ECG show?

Answer 36

AF

Question 37

What does this ECG show?

Answer 37

Atrial flutter

Question 38

What does this ECG show?

Answer 38

Atrial flutter

Question 39

What does this ECG show?

Answer 39

Atrial flutter

Question 40

What does this ECG show?

Question 41

What does this ECG show?

Answer 41

VF

Question 42

What does this ECG show?

Answer 42

Torsades de Pointes

Question 44

What does this ECG show?

Answer 44

VT