Cardiology 7.12

Question 1

V tach what happens to CO

Answer 1

it decreases, HR increases and can’t pump out enough blood

Question 2

why doesn’t CO decrease during exercise

Answer 2

the arteries dilate

Question 3

major reason SA node changes firing rate

Answer 3

input from autonomic nervous system

Question 4

increased vagal tone, another way of saying

Answer 4

Ach

Question 5

name examples of ways to decrease SA nodal firing rate

Answer 5

increased vagal tone
beta blockers
hypothyroidism
L-type Ca channel blockers
sick sinus syndrome

Question 6

E & NE do what

Answer 6

increase rate of diastolic depol

Question 7

what is major controller of SA firing at rest

Answer 7

vagal tone

Question 8

what has little effect of ventricular conduction system

Answer 8

vagal stimulation

Question 9

one consequence of pronounced bradychardia:

Answer 9

escape beats

Question 10

what is escape beat

Answer 10

losing QRS wave - example: thrd degree heart block

latent pacemakers have escaped and are driving ventricles at a much slower rate

Question 11

describe third degree heart block

Answer 11

complete blockage of AP conduction from atria to ventricles (AV node) lower pacemaker driving ventricles

Question 12

width of QRS indicitve of

Answer 12

conduction delay through ventricles

Question 13

abnormally slow SA firing can result in

Answer 13

escape beats & escape rhythms

Question 14

what is driving ventricular firing in third degree heart block

Answer 14

lower pacemakers

Question 15

what is ectopic beat

Answer 15

premature depol from sinus node

originates from site other than sinus node

Question 16

what would cause ectopic beats & ectopic rhythm

Answer 16

high catecholamines
ischemia
digitalis toxicity

Question 17

mechanism of ectopy

Answer 17

increased automaticity of latent pacemakers
abnormal automatciity of cells outside the specialized conduction system
triggered activity

Question 18

what is triggered activity

Answer 18

early after depol

delayed after depol

Question 19

what would happen to p wave in atrial premature depol

Answer 19

inverted p wave

Question 20

dra example of PAC

Answer 20

pg 176

Question 21

what does PAC stand for

Answer 21

premature atrial contraction

Question 22

PAC and PVC are examples of

Answer 22

ectopic hart beats

Question 23

what does PVC stand for

Answer 23

premature ventricular contraction

Question 24

PAC frequently caused by

Answer 24

excessive catecholamines

Question 25

two types of triggered actiity

Answer 25

DAD & EAD

Question 26

DAD stands for

Answer 26

delayed afterdepolarization

Question 27

DAD describe

Answer 27

extra depolarization. not a problem by itself, but if it depolarizes to threshold it will fire an action potential, and one AP wouldn't be a problem, but you can develop a tachycardia

Question 28

mechanism of DAD

Answer 28

Spontaneous SR calcium release, that will trigger calcium wave which activates Na-Ca exchange which produces the DAD overall there is a inward current which will depol the cell

Question 29

what does Na-Ca exchange do

Answer 29

keeps Ca levels down in cell | three sodium in for two calcium out

Question 30

what is result of Na-Ca in DAD

Answer 30

depols the cell b/c more + in than out so cell gets more +

Question 31

EAD stands for

Answer 31

early afterdepolarization

Question 32

what do you see in EAD

Answer 32

pg 183

Question 33

mechanism of EAD

Answer 33

reactivatoin of calcium current (or sodium), can lead to ventricular fibrillation

Question 34

EAD can lead to

Answer 34

ventricular fibrillation

Question 35

EAD is promoted by what

Answer 35

conditions rtaht prolong action potential duration

Question 36

examples of things that can prolong AP duration

Answer 36

``` K channel blockers inherited loss of K channels hypokalemia hypocalcemia bradycardia ```

Question 37

slower HR what hapens to AP duration

Answer 37

longer

Question 38

hypokalemia does what to Ap duration

Answer 38

hyperpolarizes and prlongs AP duration

Question 39

long QT can trigger

Answer 39

ventricular tachycardia

Question 40

pg 185

Answer 40

pg 185

Question 41

bigger the calcium current, what does it do to conduction

Answer 41

faster it will conduct

Question 42

conduction velocity in AV node, upstroke is

Answer 42

calcium current

Question 43

the bigger calcium current n AV node, what happens to velocity

Answer 43

increased

Question 44

examples of what can be a block

Answer 44

closed gap junctions, fibrosis

Question 45

two types of second degree heart block

Answer 45

Mobitz type I and II

Question 46

motibz type I

Answer 46

progressive preceeding block is preogressively longer p wave, and then it wll drop a beat

Question 47

what is mobitz type I block called

Answer 47

wenckebach block

Question 48

motbitz type II block

Answer 48

PR interval is normal | random dropped WRS (double check on this)

Question 49

bundle branch block what will it do

Answer 49

widens QRS

Question 50

what is normally last thing to repol

Answer 50

base of left ventricle

Question 51

left bundle branch block tends to shift axis to

Answer 51

left

Question 52

one biggest thing that can cuase conduction block

Answer 52

ischemia

Question 53

ischemia what does it do to K and Na

Answer 53

reduces Na and high K - so depols cell

Question 54

if you reduce the sodium currnet you will

Answer 54

reduce conduction velocity (except AV and SA node)

Question 55

pg 200

Answer 55

pg 200