Phys 2 Physiological basis of the ECG

Question 1

Electrocardiogram

Answer 1

Question 2

Characteristics of the ECG

Measures what?

deflections happen when?

Answer 2

Question 3

Where do electrodes report voltage differences?

why not between the two?

Answer 3

Question 4

What would be the deflection in each one?

Answer 4

Question 5

Avg current flow occurs where in the heart?

Answer 5

Question 6

What makes up your typical heart beat on an ECG?

(graph)

Answer 6

Question 7

Answer 7

Question 8

What is a P wave?

PR interval?

QRS complex?

ST segment?

T wave?

Answer 8

Question 9

P wave

represents what phase of AP?

Why no repolarization seen on graph?

Answer 9

Question 10

QRS complex

respresents what phase of AP?

Why 0 mv during ST segment?

Answer 10

Question 11

T wave

represents what phase of AP?

what corresponds to the ending of T waves?

Answer 11

Question 12

U wave

Answer 12

Question 13

What is a segment?

Interval?

what does each large boxes equal horizontally?

what do they mean vertically?

Answer 13

Question 14

The intervals?

when are they?

Answer 14

Question 15

Segments?

when are they?

Answer 15

Question 16

Problem?

Answer 16

Question 17

Time between dark lines?

time between light lines?

Answer 17

Can calculate time between beats

(5x.2) + (2x.04)=1.08 sec

(60 sec/min)/1.08 sec = 55.5 beats/min

Question 18

Standard (bipolar) limb leads use:

Answer 18

Question 19

Augmented limb leads

Answer 19

Question 20

Chest or precordial leads

Answer 20

Question 21

standard limbs lead axis

What makes a deflection +?

which lead is considered positive?

Answer 21

If AP is spreading towards + lead of electrode set, a + deflection will be observed

Question 22

Augmented limb leads axis

triangle

Answer 22

Question 23

Chest or precordial leads

approximate locations?

what is + and - lead?

Assigned to what axis?

Answer 23

Question 24

Lead region assignments

which lead for which part of the heart?

Answer 24

Question 25

Physiology and anatomy which lead and ecg placement goes with what anatomical position?

Answer 25

Question 26

Mean electrical Axis what is it? uses what? can tell us what type of problems? what cause these problems?

Answer 26

Question 27

MEan electrical axis If lead I and aVF are positive?

Answer 27

Question 28

Mean electrical axis If lead I is negative? potential what?

Answer 28

Question 29

Mean electrical axis If lead I is positive and aVF is negative? possible anatomical finding?

Answer 29

Question 30

Answer 30

Left: positive lead I and negative aVF Left axis deviation Right: negative lead I and positive aVF Right axis deviation

Question 31

Relationship of ECG to cadiac cycle P wave? QRS complex? T wave?

Answer 31

Question 32

Think about which ion channels are open and when during this event?