ECG

Question 1

what does one large square on an ECG represent

Answer 1

5mm = 0.2s

Question 2

what does the p wave represent

Answer 2

atrial depolarisation

Question 3

what does the QRS complex represent

Answer 3

ventricular depolarisation

Question 4

how long is a QRS complex normally

Answer 4

< 0.1s

Question 5

what does a T wave represent

Answer 5

ventricular repolarisation

Question 6

how long is a normal T wave

Answer 6

0.12-0.2s

Question 7

what does PR interval represent

Answer 7

AV nodal delay

Question 8

how long is a normal PR interval

Answer 8

0.12 - 0.2s

Question 9

what does the ST segment represent

Answer 9

ventricular contraction (systole)

Question 10

what does the TP interval represent

Answer 10

ventricular relaxation (diastole)

Question 11

how do you work out HR

Answer 11

300/no. of large squares between QRS (regular)

or number of QRS in 30 squares x 10
or number of QRS in 10 squares x 3 x 10

Question 12

what plane are the limb leads

Answer 12

frontal / vertical

Question 13

what plane are the chest leads

Answer 13

horizontal

Question 14

if there is ST elevation in the following leads where is the MI and what artery is blocked
leads II, III and aVF (foot of the ECG)

Answer 14

inferior - foot is inferior
shaped like a foot

right coronary artery

Question 15

if there is ST elevation in the following leads where is the MI and what artery is blocked
V1-V4

Answer 15

anterior

LAD

Question 16

if there is ST elevation in the following leads where is the MI and what artery is blocked
lead I, V5 and V6, aVL

Answer 16

lateral

circumflex artery

Question 17

if there is ST elevation in the following leads where is the MI
V1 - V3

Answer 17

anteroseptal

Question 18

what is cardiac axis

Answer 18

the overall direction of electrical spread within the heart

Question 19

what should the cardiac axis be in a healthy person

Answer 19

11 o’clock to 5 o’clock

Question 20

what leads do you look at to determine cardiac axis

Answer 20

lead I II and III

Question 21

what should you always remember when reading an ECG

Answer 21

check patient details
check date and time
check calibration

Question 22

what should you look for in the rhythm strip (II)

Answer 22

regular / irregular
HR
P waves
what is the PR interval
is each p wave followed by a QRS
is each ORS preceded by a p wave
is QRS normal

Question 23

what ECG changes would be seen in STEMI

Answer 23

ST elevation
new onset BBB
T wave inversion

Question 24

what ECG changes would be seen in NSTEMI

Answer 24

no ST elevation

may be ST segment depression or T wave inversion

Question 25

what does ST depression show

Answer 25

ischaemia

Question 26

what ECG changes would be seen in Torsades de Pointes

Answer 26

long QT interval | wide and continually changing QRS

Question 27

what is the treatment for TdP

Answer 27

Iv magnesium sulfate

Question 28

``` what is the pathology: tall tented T waves wide/bizarre QRS complexes long PR interval severe bradycardia sine wave pattern ```

Answer 28

hyperkalaemia

Question 29

what is the pathology: prolonged PR interval small inverted T waves - go down then up ST segment depression

Answer 29

hypokalaemia

Question 30

what is the pathology: sinus tachycardia RH strain T wave inversion in anterior leads

Answer 30

PE

Question 31

what is the pathology: | Broad QRS with slurred upstroke on R wave (delta wave)

Answer 31

Wolff-parkinson white syndrome

Question 32

what is the ECG for SVT

Answer 32

narrow QRS | regular rhythm of 150bpm

Question 33

what is the ECG for VT

Answer 33

wide QRS - broad complex tachycardia

Question 34

if someone had wide QRS and a history or coronary artery disease/heart failure what would you suspect

Answer 34

VT

Question 35

what is the pathology: saw tooth baseline regular rhythm 150bpm

Answer 35

atrial flutter

Question 36

what is the pathology: absence of P waves irregularly irregular rhythm irregular baseline

Answer 36

Atrial fibrillation

Question 37

what is the ECG change for BBB

Answer 37

wide QRS

Question 38

what is the pathology: | fixed PR intervals > 0.2s

Answer 38

1st degree heart block

Question 39

what is seen on a ECG for 3rd degree heart block

Answer 39

very broad QRS | no association between p waves and QRS

Question 40

what is seen on an ECG for Mobitz I

Answer 40

progressive lengthening of PR interval eventually resulting in dropped beat usually 3:1

Question 41

what is seen on an ECG for mobitz II

Answer 41

intermittent dropped beats without lengthening - P wave often not followed by QRS usually 2:1

Question 42

what is the pathology: saddle shaped ST elevation PR depression

Answer 42

acute pericarditis

Question 43

what is seen in the digoxin effect on an ECG

Answer 43

depressed ST segments in V5 and V6

Question 44

what is seen in cardiac tamponade

Answer 44

electrical alternans

Question 45

what is one of the first ECG changes seen in an MI

Answer 45

tall peaked T waves