EKG (Newman)

Question 1

What is the most cause of stroke?

Answer 1

atrial fibrillation

Question 2

What is the most common cause of suden cardiac death?

Answer 2

ventricular fibrillation

Question 3

What does the P wave represent?

Answer 3

depolarization of the atria

Question 4

What does the Q wave represent?

Answer 4

polarization of the septum

Question 5

What does the RS complex represent

Answer 5

depolarization of ventricles

Question 6

What does an elevated ST segment indicate

Answer 6

ST elevation MI

Question 7

What does an DE-elevated ST segment indicate

Answer 7

ischemia

Question 8

WHat does the T wave represent

Answer 8

repolarization

Question 9

What causes a positive deflection on an EKG?

Answer 9

vector is parallel to _____

Question 10

What causes a negative deflection on an EKG?

Answer 10

vector is perpendicular to ______

Question 11

What causes a straight line on an EKG?

Answer 11

???

Question 12

At rest, phase 4 is appx ___ mV
With depolarization ____ floods into the cell and the cell becomes _____ mV
At phase 1 ____ ions are moving in and ___ ions are moving out
At phase 2 ____ ions are moving in and ___ ions are moving out
At phase 3, ____ ions are moving in and ___ ions are moving out

Answer 12

-90 mV
Na  +20 mV
Cl- in and K+ out
Ca in and K+ out
only K+ out

Question 13

T or F: all heart tissue has the same AP

Answer 13

F

Question 14

What ion drives an AP conduction in the heart?

Answer 14

Ca influx

Question 15

During the AP the cell cannot be stimulated to generate another AP during the _____ period

Answer 15

refractory (phase 1-2 is absolute and phse 3 is relative)

Question 16

What is the threshold potential of automat. cells?

Answer 16

-65 mV

Question 17

What is the refractory period?

Answer 17

period when the myocyte cannot generate another AP

Question 18

what are 2 impt concepts for generation of dysrryhtmias?

Answer 18

refractory and threshold

Question 19

The AV node depolarization is represneted by _____ on the EKG

Answer 19

PR segment

Question 20

The depolarization of septa is represneted by _____ on the EKG

Answer 20

Q wave

Question 21

depolarization of ventricles

Answer 21

RS complex

Question 22

repolarization of ventricles

Answer 22

T wave

Question 23

increased cardiac muscle mass

Answer 23

hypertrophy

Question 24

How is hypertrophy Dx?

Answer 24

height of R wave increased

Question 25

What is the most common cause of LFT ventricular hypertrophy

Answer 25

HTN | **at risk risk for coronary events

Question 26

What does a wide QRS complex indicate?

Answer 26

delayed activation of ventricles since the tissue is blocked (delay in AP conduction)

Question 27

What does a prolonged PR segment indicate

Answer 27

heart block due to AV node disease

Question 28

WHat are the 2 major mech of cardiac arrhythmias?

Answer 28

altered automaticity (alt phase 4) and altered reentry

Question 29

Why does enhanced automaticity occur?

Answer 29

phase 4 has been altered and risen to threshold potential --> ******a cell fires when it is not supposed to

Question 30

What causes a cell to inc threshold potential and depolarize inappropritely?

Answer 30

``` low K+ (inc automaticity) inc symp activity (meds, anxiety) low O2 high CO2 (emphysema) low pH (kidney shut down) fever digitalis (Rx) previous AP*** ```

Question 31

What is triggered automaticity?

Answer 31

previous AP stimuates an inapproprate firing of AP

Question 32

What is reentry?

Answer 32

electrical impulse comes down normal pathway but will become blocked at some point and cause a detour of AP along an alternative pathway (circuit loop) and then come back up the original pathway (which is NO LONGER refractory) --> continuous loop of activation --

Question 33

In order to have cardiac reentry one must have a _______ pathway

Answer 33

continuous (loop)

Question 34

What are the 3 requirements of reentry

Answer 34

unidirectional block of impulse continuous loop pathway alt pathway has slower conduction velocity

Question 35

WHere is a naturally occurring circuit loop found?

Answer 35

atria???

Question 36

What is the cause /mechanism of palpitations

Answer 36

block in (atrial?) AV node pathway (natural) that causes arrythmia/reentry

Question 37

conduction block in the ventricle -->

Answer 37

ventricular tachycardia

Question 38

dyrrthmias are likely caused by ____

Answer 38

enchanced automaticity or re-entry

Question 39

no p waves

Answer 39

enhanced automaticity junctional rhythm impused started somewhere in AV node

Question 40

multifocal atrial tachycardia

Answer 40

bunch of atria AP fired inappropriately

Question 41

person born with alternative pathway that joins atria to ventricles in a rapid pathway (HR of 300 bpm)

Answer 41

wolff-parkinson- white syndrome | with supraventricualr tachycardia

Question 42

What to anti-arrhythmic agents do?

Answer 42

- reduce automaticity (reduce pahse 4 threshold potential) | - prevent reentry (block alternative pathway that leads to re-entry)

Question 43

Elevated Ca and decreased K will (increase/decrease) automaticity.

Answer 43

increase

Question 44

Elevated K and decreased Ca will (increase/decrease) automaticity.

Answer 44

decrease