ECG

Question 1

electrocardiograph produces electrocardiogram true/false

Answer 1

true

Question 2

where is lead I between

Answer 2

right arm - left arm

Question 3

where is lead II between

Answer 3

right arm - left leg

Question 4

where is lead III between

Answer 4

left arm - left leg

Question 5

what is the positioning for the precordial leads

Answer 5

V1 - 4th intercostal space on right parasternal line
V2 - 4th intercostal space on left parasternal line
V3 - between V2 and V4
V4 - 5th intercostal space midclavicular line
V5 - follows horizontal line - ant axillary
V6 - follows horizontal line - midaxillary

Question 6

positive wave indicates

Answer 6

moving towards the electrode

Question 7

what does the P wave represent and how long does it normally last

Answer 7

atrial depolarisation

0.08-0.1 seconds

Question 8

what does the PR interval represent and how long does it normally last

Answer 8

AV nodal delay

0.12-0.2 seconds

Question 9

what does the QRS complex represent and how long does it normally last

Answer 9

ventricular depolarisation

0.12 seconds

Question 10

what does the T wave represent

Answer 10

ventricular repolarisation

Question 11

how do you calculate a regular heart rate

Answer 11

300/(number of large squares in R-R interval)

Question 12

how do you calculate an irregular heart rate

Answer 12

300/(number of QRS peaks in 6 boxes)

Question 13

right axis deviation would show

Answer 13

Lead I negative

Lead III positive

Question 14

left axis deviation would show

Answer 14

Lead I positive

Lead III negative

Question 15

right axis deviation is a sign of

Answer 15

right ventricular hypertrophy

Question 16

left axis deviation is a sign of

Answer 16

conduction defects

Question 17

the absence of P waves is likely due to

Answer 17

atrial fibrillation

atrial flutter

Question 18

what is the ECG characteristic of atrial flutter

Answer 18

saw tooth ECG

Question 19

prolonged PR interval is a sign of

Answer 19

AV node block

Question 20

shortened PR interval arises because

Answer 20

the conduction originates somewhere closer to the AV node - eg accessory pathway

Question 21

shortened PR interval causes what condition

Answer 21

Wolf Parkinsons White syndrome

Question 22

Delta waves are due to

Answer 22

shortened PR interval, slurred QRS upstroke and classical sign of WPW syndrome

Question 23

QRS complex of <0.12 secs likely to be

Answer 23

supraventricular tachycardia

Question 24

QRS complex of >0.12 secs likely to be

Answer 24

ventricular tachycardia

Question 25

are Q waves always pathological

Answer 25

no

Question 26

what are pathological Q waves a sign of

Answer 26

previous MI

Question 27

to diagnose a STEMI ST elevation must be present

Answer 27

> 1mm in 2 or more contiguous leads

>2mm in 2 or more precordial leads

Question 28

ST depression is a sign of

Answer 28

myocardial ischaemia

Question 29

tall T waves are a sign of

Answer 29

hyperkalaemia

Question 30

when describing an ECG what must be covered

Answer 30

patient name and DoB
date and time the ECG was recorded 
calibration 
electrical activity present 
calculate HR and see if rhythm is regular 
cardiac axis 
P waves present, describe, followed by QRS
ST abnormalities

Question 31

how many seconds is a big box on ECG paper

Answer 31

0.2 seconds