01 - Cardiac Phys and EKG

Question 0

EKG is the recording of the hearts

Answer 0

Electrical activity

Question 1

The heart has electrical activity known as

Answer 1

Action potentials

Question 2

The heart acts as a _____ that generates electrical currents that can be measured on the

Answer 2

Pump

Skin surface

Question 3

Pulmonary circulation is a ____ resistance and pressure system

Answer 3

Low

25/10 mmHg

Question 4

Systemic circulation is a ____ resistance and pressure system

Answer 4

High

120/80 mmHg

Question 5

Review charts

Answer 5

Do that

Question 6

Three types of cardiac cells

Answer 6

Pacemaker - electrical power source
Electrical conducting - hard wiring
Myocardial - contractile machinery

Question 7

At rest, the Vm of pacemaker cells is

Answer 7

Constant

Both the inside and outside of the cell are at constant potential

Question 8

How big is a cardiac pacemaker cell?

Answer 8

5-10 um

Question 9

During an action potential, Vm of a pacemaker cell is

Answer 9

Not constant
Current is flowing
Inside and outside are not constant

Question 10

An action potential propagating away from the positive EKG lead produces what kind of signal?

Answer 10

Negative

AP produces positive signal when propagating toward positive lead

Question 11

Rapid depolarization correlates to

Answer 11

Sodium influx

Question 12

At the plateau, there is calcium

Answer 12

Influx

Question 13

During repolarization, there is a

Answer 13

Potassium EFFLUX

Question 14

What are the pacemakers of the heart?

Answer 14

SA and AV node

Question 15

Which is the dominant pacemaker of the heart? What is it’s rate of impulse?

Answer 15

SA node

60-100 bum

Question 16

How big are myocardial cells?

Answer 16

50-100 um

Question 17

The magnitude and polarity of an EKG signal depends on

Answer 17

Depolarizing or repolarizing

Position and orientation of electrodes

Question 18

When depolarization begins, it generates a ______ deflection

Answer 18

Positive

The EKG returns to baseline when the pos and neg charges are balanced

Question 19

The negative deflection is formed when the wave of polarization

Answer 19

Recedes from the electrode

The fully depolarized cell causes the ECG to return to baseline

Question 20

The effects of repolarization are similar to that of depolarization except that the charges are

Answer 20

Reversed

Question 21

The placement of bipolar limb leads on the three lead EKG is known as

Answer 21

Einthoven Triangle

Question 22

Augmented voltage leads (aV) utilize one bipolar limb electrode as _____, and the other two as a _______ negative lead

Answer 22

Positive

Combined

Question 23

Describe the unipolar limb leads: aVR aVL aVF

Answer 23

aVR - right arm positive, left arm and leg negative
aVL- left arm positive, right arm and left leg negative
aVF - left foot positive, arms negative

Question 24

Lead II yields the most information about

Answer 24

Ischemia in the left ventricle and septum; arrhythmias in the right atrium

Question 25

Position of lead I

Answer 25

0

Question 26

Position of lead II

Answer 26

60

Question 27

Position of lead III

Answer 27

120

Question 28

Position of aVL

Answer 28

-30

Question 29

Position of aVR

Answer 29

-150

Question 30

Position of aVF

Answer 30

90

Question 31

The chest leads v1-v6 (precordial) are positioned in successive steps at

Answer 31

Right margin of the sternum to the left edge of the thorax

Question 32

If v1 through v6 are imagined to be spokes of wheel, their horizontal plane cuts the body into

Answer 32

Top and bottom halves Oh ok

Question 33

This lead produces a mostly negative deflection

Answer 33

V1

Question 34

This lead describes a straight line directly from the patients back through the anterior aspect of the chest

Answer 34

V2

Question 35

What is the common wall shared by the right and left ventricles? What runs through this wall?

Answer 35

Interventricular septum | Right and left bundle branches

Question 36

Which leads best describe conduction abnormalities of the bundle branches?

Answer 36

V3 and V4

Question 37

What are leads V5 and V6 referred to as?

Answer 37

Left chest leads | They are oriented along the left axiliary lines

Question 38

This six limb leads can be modified limb leads represented by which four trunk leads?

Answer 38

V1-V4 | So that all leads can be placed on the trunk of the body

Question 39

Six clinical uses of the EKG?

Answer 39

Detection of arrhythmias and cardiac abnormalities Indication of myocardial damage Detection of electrolyte disturbances Screening tool for diagnosis of ischemic disease Can indicate anatomic and physiological state of the heart Diagnose some noncardiac pathology

Question 40

Depolarization moves from the linings (endocardium) of the ventricular cavity _______ to the epicardial surface of the ventricle

Answer 40

Outward

Question 41

The only conducting path between the atrium and ventricle is?

Answer 41

AV node

Question 42

When depolarization reaches the myocardial cell, calcium released causes the cell to contract. What is this process called?

Answer 42

Excitation contraction coupling