deck_16882703

Question 1

What are the cases of deflection in the ECG?

Answer 1

Like towards like = positive deflection So, postive charge (depolarization) toward the positive electrode = positive deflection

Question 2

When is the main thing that we focus on in a lead?

Answer 2

The position of the positive electrode (its the one that measures)

Question 3

What makes up einthoven’s triangle?

Answer 3

The first three leads (I, II, III)

Question 4

What is the position of lead I?

Answer 4

The postive electrode is at the left arm, and the negative is at the right (remember the first photo)

Question 5

What is the position of lead II?

Answer 5

Postive electrode on the left leg, Negative electrode on the right arm (remeber the second photo that he showed us)

Question 6

What is the position of lead III ?

Answer 6

Postive electrode at the left leg, Negative electrode at the left shoulder.

Question 7

What lead is the usually the best view of the heart?

Answer 7

Lead II, bc it shows us the depolariztion of the apex of the heart.

Question 8

What is the p wave?

Answer 8

Results from the movement of a wave of depolarization as the AP spreads away from the SA node throughout the atria (at 1 m/s).

Question 9

What is the PQ interval?

Answer 9

Is the time of atrial depolarization plus the time of the passage of the action potential through the av node.

Question 10

What is QRS?

Answer 10

QRS reflects the steps of ventricular depolarization.

(bc it is 3 steps)

Question 11

What is the ST segment?

Answer 11

The ST segment reflects the period of time that the ventricles are fully depolarized during the plateau phase of the ventricular action potential.

Question 12

What is the T wave?

Answer 12

The T wave represents ventricular repolarization.

Question 13

What is the QT interval?

Answer 13

The QT interval represents the period of time from the beginning of ventricular depolarization to the end of ventricular repolarization

Question 14

What is a mnemonic to memorize P wave, PQ, QRS, ST, T wave, QT in that order?

Answer 14

Pretty People Quickly Run Straight Towards QTs”

P wave: Pretty
PQ interval: People Quickly
QRS complex: Run
ST segment: Straight
T wave: Towards
QT interval: Qt’s

Question 15

What is the Q deflection of the QRS complex?

Answer 15

It is a small negtive deflection on the ECG bc of the spreading of the AP from the left ventricle (where the postive electrode is located) to the right ventricle (away from the postive electrode).

Question 16

What is the R wave of the QRS complex? Why is there a sharp spike in the ECG?

Answer 16

Is the segment where the early ventricular depolarization occurs

The strong spike in the ECG is due to the fact that LV is more muscular than the RV, so it “steals” more electricity and takes it towards the postive electrode.

Question 17

What is the S wave of the QRS complex? Why is there a sharp spike downwards in the ECG?

Answer 17

The depolarization reaches the purknjie fibers and therefore goes up the walls of the heart (away from the postive electrode) causing a sharp spike downwards on the ecg.

Question 18

What is the t wave? Why does it have a postive deflection?

Answer 18

The repolarization of the ventricles.

It has a postive deflection bc the negative charges are moving away from the electrode.

Question 19

What is the duration of the pq/pr interval?

Answer 19

0.12-0.2 seconds

Question 20

What is the duration of the qt interval?

Answer 20

< 400ms

Question 21

What is the QT interval?

Answer 21

From Q deflection, till T wave.

From the start of venticular depolarization, till the end of venticular repolarization,

Question 22

What takes place during th QT segment? Diatole or systole?

Answer 22

Venticular systole

Question 23

What is the PQ/PR segement?

Answer 23

The period of time between the end of p wave, and begining of Q deflection.

The time that the AP takes to pass through the AV node.

Question 24

What is the duration of the ST segment?

Answer 24

Lasts about 120 ms

Question 25

What is a cause of prolongation of the PQ interval

Answer 25

may suggest damage to the atrial conducting pathways or slowing of conduction via the AV node.

Question 26

What is a cause of prolongation of the QT interval

Answer 26

myocardial damage, coronary ischemia, conduction abnormalities as well as by genetic syndromes

Question 27

What is a common cause of ST segment elevation?

Answer 27

Myocardial Infarction

Question 28

What is a common cause of ST segment depression?

Answer 28

common during angina for example due to ischemia/coronary insufficiency.

Question 29

What is the R-R interval?

Answer 29

time between successive heart beats

Question 30

How do you measure the heart rate based on the R-R interval?

Answer 30

Heart rate (beats per min) = 60 / R-R interval (in sec).

Question 31

What is the TP segment?

Answer 31

The period between the T wave and the start of the new P wave. The period of diastole

Question 32

Where are the limb leads placed?

Answer 32

Left and right wrists and left and right ankles

Question 33

What is the signifcance of the 4th lead

Answer 33

it is placed on the right ankle and acts as a neutral lead to bridge the conncection

Question 34

What are the electrode positions for the avR?

Answer 34

av**R** **right arm**+ve **left arm** -ve l**eft foot** -ve

Question 35

What are the electrode positions for the avL?

Answer 35

**Left arm** is +ve, **right arm** is -ve, **left foot** is -ve.

Question 36

What are the electrode positions for the avF?

Answer 36

**Left foot is** +ve **Right and left arm** -ve

Question 37

what are the frontal leads? In what plane do they record?

Answer 37

Lead I Lead II Lead III avR avL avF **Record in:** Frontal plane

Question 38

What are the precordial leads? How do they record? What is unique about them?

Answer 38

**Special:** All Precordial leads are positive. Share a common negative (Wilson’s central terminal) **record** electrical activity in a **transverse plane** through the heart.

Question 39

What are the angles of the augmented leads?

Answer 39

avR: -150 avL= -30 avF=+90

Question 40

How many seconds does the ECG trace cover?

Answer 40

10 seconds of time?

Question 41

What do the top 3 sets trace?

Answer 41

2.5 seconds from each of the 12 leads

Question 42

What do the bottom 3 sets trace?

Answer 42

some chosen leads that are traced for the whole 10 second period (V1, Lead II and V5 over a 10 second period in this example)

Question 43

What are the leads that look at the heart inferiorly?

Answer 43

aVF bc inferior has F II, III (bc they are small numbers) Pia bc pia matter is on the bottom RCA bc right is deoxygenated, so inferior to oxygenated

Question 44

What are the leads that look at the heart lateraly?

Answer 44

bc it is lats, so, strong, so V5 V6, aV**L** and **L**ats, **I** Looks like an L and the Lc 500 has a strong engine so lats LCx

Question 45

What are the leads that look at the heart anteriorly?

Answer 45

V3 and V4 bc it is higher than septal Lad bc the v3 and v4 will be your daily driver