ECG

Question 1

What is P?

Answer 1

atrial depolarisation

Question 2

How long does P usually last?

Answer 2

0.08-0.10seconds

Question 3

What is the QRS complex?

Answer 3

ventricular depolarisation

Question 4

How long does the QRS complex usually last?

Answer 4

less than 0.10 seconds

Question 5

What is T?

Answer 5

ventricular repolarisation

Question 6

What occurs in the PR interval?

Answer 6

largely AV nodal delay

Question 7

How long is the PR interval usually?

Answer 7

0.12-0.2 seconds

Question 8

What occurs in the ST segment?

Answer 8

ventricular contraction

Question 9

What occurs in the TP interval?

Answer 9

ventricular relaxation

Question 10

What is the ECG paper speed?

Answer 10

25mm/second

Question 11

How do you calculate the heart rate if it is regular?

Answer 11

300 divided by the number of large squares between two beats (R-R interval)

Question 12

How do you calculate the heart rate if it is irregular?

Answer 12

number of QRS complexes in 30 large squares multiplied by 10

Question 13

How many seconds does one large box stand for?

Answer 13

0.2

Question 14

How many seconds does one small box stand for?

Answer 14

0.04

Question 15

Where do the limb electrodes go?

Answer 15

RA, LA, LL and RL (neutral)

Question 16

What are the 6 limb leads?

Answer 16

I, II, III, aVF, aVL, aVR

Question 17

Why is aVR inverted?

Answer 17

the predominant vector is depolarisation moving away from the electrode

Question 18

Why are the P and T waves poorly resolved in limb lead III?

Answer 18

the predominant vector is approx. perpendicular to the lead axis

Question 19

The predominant vector is approx. parallel to lead axis in limb lead II. What does this result in?

Answer 19

well resolved P and T waves

Question 20

What is a lead?

Answer 20

imagine a line between two electrodes

Question 21

Where is the neutral, reference electrode?

Answer 21

RL

Question 22

Where is V1?

Answer 22

right sternal edge, 4th intercostal space

Question 23

Where is V2?

Answer 23

left sternal edge, 4th intercostal space

Question 24

Where is V3?

Answer 24

half way between V2 and V4

Question 25

Where is V4?

Answer 25

5th intercostal space, midclavicular line

Question 26

Where is V5?

Answer 26

anterior axillary line

Question 27

Where is V6?

Answer 27

mid axillary line

Question 28

What does broad complex tachycardia show?

Answer 28

A ventricular problem

Question 29

What do narrow QRS complexes show?

Answer 29

Atrial origin

Question 30

What do broad QRS complexes with slurred upstroke on the R/delta wave show?

Answer 30

Wolff-Parkinson-White syndrome

Question 31

What does an absent P wave show?

Answer 31

sinoatrial block

Question 32

Bifid P wave?

Answer 32

LA hypertrophy e.g. in mitral stenosis

Question 33

Peaked P wave?

Answer 33

RA hypertrophy e.g. pulmonary HT, tricuspid stenosis

Question 34

ST depression?

Answer 34

myocardial ischaemia

Question 35

ST elevation?

Answer 35

Acute MI

Question 36

'Saddle' shaped ST elevation?

Answer 36

acute constrictive pericarditis

Question 37

Irregularly irregular rhythm?

Answer 37

AF

Question 38

Sawtooth rhythm strip?

Answer 38

atrial flutter

Question 39

long PR interval?

Answer 39

1st degree heart block

Question 40

Describe Mobitz type I on an ECG.

Answer 40

PR interval gradually decreasing from cycle to cycle until the AV node completely fails and a QRS complex is missing

Question 41

PR interval is constant, but every nth QRS is missing?

Answer 41

Mobitz type II

Question 42

W pattern in V1, M pattern in V6?

Answer 42

LBBB

Question 43

M pattern in V1, W pattern in V5?

Answer 43

RBBB

Question 44

dissociation between P waves and QRS complexes?

Answer 44

complete heart block

Question 45

What are the lateral ECG leads? e.g. for describing an MI

Answer 45

I, aVL, V5-6

Question 46

What are the septal ECG leads?

Answer 46

V1-2

Question 47

What are the inferior ECG leads?

Answer 47

II, III, aVF

Question 48

What are the anterior ECG leads?

Answer 48

V3-4