Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

CARDIO > Interpreting the ECG > Flashcards

Interpreting the ECG Flashcards

1
Q

what produces HR

A

SAN

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what does an ECG measure

A

indirect info of electrical activity of the heart

signals correspond to depolarisation and repolarisation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is the main test to assess myocardial infarction & ischemia

A

ECG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what does the electrical activity between myocytes produce

A

current flow in heart and surrounding tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is an electrocardiograph

A

potential differences on distant sites on body surfaces detected by electrodes places on the skin coupled to a sensitive recording device
12 Leads

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is a dipole

A

separation of charges

an ECG shows dipoles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what does every electrical vector possess

A

magnitude and direction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

how is the magnitude of an electrical vector determined

A

by mass of cardiac muscle in causing the signal this is caused by atria + ventricles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

how is the direction of an electrical vector determined

A

by overall activity of the heart at any instant time and varies in cardiac cycle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is a lead in an ECG

A

imaginary line between 2 or more electrodes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what are the 2 electrodes that form a lead responsible for

A

1 is the -ve lead

the other is the +ve recording lead

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what happens when depolarisation moves towards a recording electrode

A

upward stroke on ECG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what happens when depolarisation moves away from the recording electrode

A

downward stroke on ECG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is the name give to when there is no movement towards or away from the recording electrode

A

ISOPOTENTIAL

no deflection on the ECG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what happens when repolarisation moves towards recording electrode

A

downward stroke

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what happens when repolarisation moves away from recording electrode

A

upward stoke

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what are the 3 bipolar standard limb leads and where do they connect

A

Lead I: RA (-ve) to LA (+ve)
Lead II: RA (-ve) to LL (+ve)
Lead III: LA (-ve) to LL (+ve)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

In lead II what direction is the P wave and why

A

SAN inferiorly to left

depolarisation is moving towards recording electrode producing a normally upward deflection (120ms)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

In lead II what direction is the Q wave and why

A

left to right depolarization of the interventricular septum moving slightly away from the recording electrode
< 0.1 sec

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what direction is the R wave and why

A

depolarization of the main ventricular mass moving towards the recording electrode so upward stroke

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what direction is the S wave and why

A

depolarization of ventricles at the base of the heart moving away from the recording electrode so downwards deflection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

is the first positive/upward deflection always called the R wave even if there is no preceding Q wave

23
Q

what direction is the T wave

A

ventricular repolarization moving in a direction opposite to that of depolarization accounts for the usually observed upward deflection

24
Q

what does the PR interval show

A

largely AVN delay (0.12 – 0.2 sec)
start of P wave to start of QRS complex
time for SAN to reach the ventricles

25
what does the ST segment represent
ventricular systole end of QRS complex to start of the T wave usually isoelectric
26
what does the QR interval show and how long is it supposed to last in a person with a HR of 60
``` depolarisation + repolarization start of QRS complex to end of T wave whole HR 440 ms in males 460 ms in females ```
27
what does the TP segment show
ventricular diastole
28
what are the 3 augmented voltage (aV) leads
aVR (right) aVL (left) aVF (foot)
29
how many electrodes are involved in the augmented voltage leads
3 | 1 recording electrode and the other 2 electrodes are electrically linked together
30
what does the hexacial reference system state
3 inferiorly, 2 diagonal, 1 from left to right
31
are aVR waves positive or negative | Explain
negative so downstroke recording electrode is on the right shoulder depolarisation is moving away from recording electrode
32
are Lead I and aVL positive or negative
positive so upstroke | lateral lead has recording electrode on the left arm and views heard from left
33
what are the inferior leads
lead II, III and aVF
34
what are the lateral leads
Lead I and aVL
35
are leads II, III and aVF positive or negative. Explain
positive so upstroke | recording electrode on left foot and views from inferior direction
36
what are the 6 chest leads (precordial leads/Wilsons Leads)
V1-V6 | electrodes of the standard limbs linked together to provide reference electrode in centre of the heard
37
why is the R wave line in V1 tiny but increases as we go from medial to lateral around the chest wall to V6
because vector changes and points towards the electrode
38
what is the position of V1
* 4th intercosstal place on right side beside the border | * Use sternal angle which is at space 2
39
position of V2
* 4th intercostal space | * Immediately left of septum
40
position of V3
• Midway between V2 and V4 (place these first)
41
position of V4
* 5th intercostal space * Mid clavicular line * If apex beat is displaced still put in this position
42
position of V5
* Same horizonatl level as V4 | * Anterior axillary line
43
position of V6
* Same horizontal level as V4 | * Midaxillary line
44
how many secs is a big square on an ECG
0.2 sec | 5mm amplitude
45
how many secs is a small square on an ECG
0.04 sec | 1 amplitude
46
how is heart rate determined by reading an ECG
300/number of large squares between beats fro regular rhythm | 300/number of large squares between R-R interval
47
what is the purpose of an ECG rhythm strip
prolonged recording of lead II to show HR and cardiac rhythm (regular rhythm has same spaces between QRS complex)
48
are limb leads I, II, III, aVF and air upstroke or downstroke
upstroke
49
is limb lead aVR upstroke | or downstroke
downstroke
50
are chest leads V1, V2 and V3 R wave downstroke or upstroke
downstroke
51
are chest leads V4, V5 and V6 R wave downstroke or upstroke
upstroke
52
what is sometimes seen in the ECG of a patient with MI
ST elevation
53
when should an exercise ECG be carried out
``` stable angina (form of ischaemic heart disease) there may be ST changes during exercise that aren't present in rest ```

CARDIO (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions