ECGs

Question 1

An electrocardiograph is the ___1____

An electrocardiogram is the ____2_____

Answer 1

1 machine

2 information generated

Question 2

When depolarisation moves towards the recording electrode the ECG generates ____1_____
When depolarisation moves away from the recording electrode the ECG generates ____2____

Answer 2

1 an upwards deflection

2 a downwards deflection

Question 3

There are __1___ leads and ____2___ electrodes (___3___)

Answer 3

1 12 leads
2 10 electrodes
3 6 chest and 4 limb

Question 4

Placement of V1

Answer 4

4th ICS immediately right of the sternum

Question 5

Placement of V2

Answer 5

4th ICS left of sternum

Question 6

Placement of V3

Answer 6

Midway between V2 and V4

Question 7

Placement of V4

Answer 7

5th ICS mid clavicular line

Question 8

Placement of V5

Answer 8

Same horizontal level as V4 but on anterior axillary line

Question 9

Placement of V6

Answer 9

Same horizontal level as V4 but on mid axillary line

Question 10

Lead 1 is from

Answer 10

Right arm to left arm

Question 11

Lead 2 is from

Answer 11

Right arm to left leg

Question 12

Lead 3

Answer 12

Left arm to left leg

Question 13

P wave is

Answer 13

Atrial depolarisation

Question 14

QRS complex is

Answer 14

Ventricular depolarisation

Question 15

T wave is

Answer 15

Ventricular repolarisation

Question 16

PR interval is

Answer 16

Start of p wave to start of QRS. Reflects the time for SA impulse to reach the ventricles, normally ).12-0.2 seconds. Strongly influenced by the AV node delay.

Question 17

ST segment is

Answer 17

End of QRS to start of T wave. Normally isoelectric. Elevation or depression is abnormal.

Question 18

QT interval is

Answer 18

start of QRS to end of T wave. Primarily reflects that time for ventricular depolarisation and depolarisation normally 0.44s in males and 0.46s in females. Prolongation may be caused by drugs.

Question 19

Calibration of ECG?

Answer 19

25mm/s

10mm/mV

Question 20

Normal resting ECG doesn’t exclude?

Answer 20

• Myocardial Infarction (heart attack)! May or may not cause characteristic ECG changes (e.g. ST elevation)
• Intermittent Rhythm Disturbance! If suspected do ambulatory ECG recording for 24 hrs or 7 days
• Stable Angina (a form of Ischaemic Heart Disease) If suspected do exercise ECG. Look for ST changes during/after exercise. Usually absent during rest!

Question 21

Tall QRS complexes usually imply

Answer 21

Left ventricular hypertrophy

Question 22

Inferior view of heart from

Answer 22

2, 3 and avF

Question 23

Lateral view of the heart from

Answer 23

1, avL, V5 and V6

Question 24

Anterior view of the heart from

Answer 24

V3-4

Question 25

Septal view

Answer 25

V1, V2

Question 26

If heart rate regular work out rate from

If irregular

Answer 26

300/ no of large squares between beats

number of QRS complexes in 30 squares x 10

Question 27

If lead 1 and AvF are both upright the axis is

Answer 27

normal

Question 28

If lead 1 is upright but AVF downwards the axis is

Answer 28

left

Question 29

If lead 1 is downwards but AVF upwards the axis is

Answer 29

right

Question 30

Ventricular ectopics may have broad

Answer 30

QRS complexes

Question 31

Length of normal qrs?

Answer 31

0.12 seconds (3 small squares)

Question 32

What change will occur first on ECG in acute MI?

Answer 32

Tall T waves

Question 33

Common artery affected in inferior MI?

Answer 33

Right coronary artery

Question 34

Common artery affected in anterior MI?

Answer 34

Left anterior descending

Question 35

Common artery affected in high lateral MI?

Answer 35

A diagonal branch of LAD

Question 36

Common artery affected by low lateral MI?

Answer 36

Obtuse marginal branch of the circumflex artery

Question 37

What is a narrow qrs typical of?

Answer 37

SVT