ECG

Question 1

what does the p wave show, how long should it last

Answer 1

atrial depolarisation (0.08-0.1 sec)

Question 2

what does the QRS complex show and how long should it last

Answer 2

ventricular depolarisation (<0.10 secs)

Question 3

what does T wave show

Answer 3

ventricular repolarisation

Question 4

what does PR interval show, how long should it last

Answer 4

AV nodal delay/ atrial contraction (0.12-0.2)

Question 5

what does the ST segment show

Answer 5

ventricular contraction

Question 6

how do you calculate HR from an ECG

Answer 6

300 divided by the number of large boxes between QRS. or count QRS in 3p boxes and x 10

Question 7

where do you place the standard limb leads

Answer 7

lead 1: RA LA
lead 2: RA LL
lead 3: LA LL

Question 8

what does a positive electrode reading show

Answer 8

wave of depolarisation moves towards it

Question 9

where does the wave of depolarisation travel, creating a diapole

Answer 9

from atrium to ventricles, positive move towards ventricles

Question 10

what are the 3 augmented limb leads

Answer 10

aVF, aVR, aVL

Question 11

what leads show the inferior part of the heart

Answer 11

aVF, lead II and III

Question 12

an MI in the inferior part of the heart is normally in what artery

Answer 12

right coronary

Question 13

what leads show posterior part of the heart

Answer 13

V1-V2

Question 14

an MI in the posterior part of the heart is normally in what artery

Answer 14

left circumflex

Question 15

what leads show anteroseptal part of heart

Answer 15

v1-V4

Question 16

an MI in the anteroseptal part of the heart is normally in what artery

Answer 16

LAD

Question 17

what leads show anterolateral part of hear

Answer 17

V4-V6

Question 18

an MI in the anterolateral part of the heart is normally in what artery

Answer 18

left LAD or circumflex

Question 19

what would show right deviation

Answer 19

aVF up and lead I down

Question 20

what would show left sided deviation

Answer 20

aVF down and lead I up

Question 21

what do absent p waves mean

Answer 21

not in sinus rhythm

Question 22

what can p waves tell us

Answer 22

atrial fib or atrial flutter (sawtooth)

Question 23

what can PR intervals show

Answer 23

prolonged PR (over o.2) shows 1st degree heart block 
slow PR increase until dropped beat = second degree 
complete dissociation between p and QRS = complete heart block

Question 24

what can QRS complexes show

Answer 24

broad = LBBB
tall = ventricular hypertrophy
slurred upstroke = delta wave = WPWS

Question 25

what can ST segments show

Answer 25

ST elevstion = MI

depression = myocardial ischaemia

Question 26

what can T waves show

Answer 26

hyperkalaemia