# ECG Flashcards

1
Q

What does the p-wave represent

A

Atrial depolarisation

2
Q

What causes the p-wave

A

SA node

3
Q

How many squares is 1 second

A

5

4
Q

What does 5 big squares on the graph represent

A

1s

5
Q

What does 1 big square represent

A

0.2 seconds (200ms)

6
Q

What is 0.2s on the graph

A

1 big square or 5 small squares

7
Q

What is 5 small squares

A

0.2 seconds

8
Q

What is 0.04 s (40ms)

A

1 small square

9
Q

What is 1 small square

A

0.04 s 40ms)

10
Q

What are the typical settings on a voltage time graph

Speed
Voltage

A

Speed = 25 mm/sec

Voltage = 10 mm/mV

11
Q

What voltage does one big square represent

A

0.5 mV

12
Q

What voltage does 2 big squares represent

A

1 mV

13
Q

Used a voltage time graph how do you calculate rate (bpm)

A

300/no. of large squares between cardiac cycle

OR

cycles in 10 seconds x 6

14
Q

What is the equation of Ohm’s law

A

V = IR

Voltage = current x resistance

15
Q

On an ECG lead what does a positive deflection show

A

16
Q

On an ECG what does a baseline/isoelectric point show

A

No net current flow in direction of lead

17
Q

On an ECG what does a negative deflection show

A

Nett current flow away from lead

18
Q

What is the normal value of the PR interval

A

120-200 ms

3-5 small squares

19
Q

What does a long PR interval show

A

1st degree heart block

Delayed AV conduction

20
Q

What is the normal range for QRS complex

A

Less than 120ms

3 small squares

21
Q

What is the QR interval a measure of

A

Time to ventricular repolarisation

22
Q

What is the QR interval

A

Time from onset of QRS to end of T

23
Q

What is the normal valve for QT interval for men

A

350-440 ms

24
Q

What is the normal value of QT interval for women

A

350-460 ms

25
Q

What does the PR segment represent

A

Av node holding charge

26
Q

What does the QRS wave represent

A

Ventricular depolarisation

27
Q

What does the T-wave represent

A

Ventricular repolarisation

28
Q

How many leads does an ECG have

A

12

29
Q

What is the division of the 12 leads

A

3 bipolar limb leads V1, V2, V3

3 Augmented unipolar limb leads avF, avR, avL

30
Q

Which leads look at the heart in a frontal plane

A

bipolar and augmented

31
Q

What leads look at the heart in a horizontal section

A

precordial

32
Q

A

RA to LA

33
Q

A

RA to LL

34
Q

A

LA to LL

35
Q

What is Lead I looking at

A

Left/lateral heart

36
Q

Where is lead II and III looking at

A

Inferior heart

37
Q

How do you think leads are looking at the heart

A

From positive to negative

38
Q

Where is electrode AVR looking

A

Right side of heart

39
Q

Where is electrode AVF looking

A

Inferior side of heart

40
Q

Where does electrode AVL looking

A

Left and lateral side

41
Q

What is the placement of the 6 precordial/chest leads

A

V1 - 4th intercostal space R
V2 - 4th intercostal space L

V4 - 5th intercostal space L

V6 - 5th intercostal midaxillary line

42
Q

What does V1/2 pick up

A

Intraventricular septum

43
Q

What does V3/4 pick up

A

Anterior wall

44
Q

What does V5/6 pick up

A

Left lateral wall