Cardiovascular Physiology Lecture 8

Front 1

what are tachyarrhythmias?

Back 1

any rhythm disturbance that occurs at a rapid rate

Front 2

what is produced by tachyarrhythmias?

Back 2

homodynamic compromise secondary to inadequate stroke volume

Front 3

any rhythm disturbance that occurs at a rapid rate, is called what?

Back 3

tachyarrhythmias

Front 4

what is a supraventricular tachycardia?

Back 4

a catch-all phrase that encompasses a variety of arrhythmias distinguished by their anatomical location 'above' the ventricles

Front 5

what are some supraventricular tachycardia?

Back 5

sinus tachycardia, atrial tachycardia, and junctional tachycardia

Front 6

what does tach stand for?

Back 6

tachycardia

Front 7

what does junctional stand for?

Back 7

nodal

Front 8

what can sinus tachycardia be classified as?

Back 8

supraventricular tachycardia

Front 9

what can atrial tachycardia be classified as?

Back 9

supraventricular tachycardia

Front 10

what can junctional tachycardia be classified as?

Back 10

supraventricular tachycardia

Front 11

hemodynamic compromise secondary to inadequate stroke volume is called what?

Back 11

tachyarrhythmias

Front 12

what is ectopy?

Back 12

any abnormality of impulse generation by cells that spontaneously depolarize to threshold voltage before the SA node (thus becoming ectopic pacemakers)

Front 13

any abnormality of impulse generation by cells that spontaneously depolarize to threshold voltage before the SA node (thus becoming ectopic pacemakers), is called what?

Back 13

ectopy

Front 14

what are ectopic pacemakers?

Back 14

cells that spontaneously depolarize to threshhold before the SA node, creating abnormality of impulse generation

Front 15

what are some examples of causes of ectopy?

Back 15

electrolyte distrubances, hypoxemia, ischemia, trauma, inflammation, infection

Front 16

what is ischemia?

Back 16

restriction in blood supply

Front 17

electrolyte disturbance can cause what?

Back 17

ectopy

Front 18

hypoxemia can cause what?

Back 18

ectopy

Front 19

ischemia can cause what?

Back 19

ectopy

Front 20

trauma, inflammation, and infection can cause what?

Back 20

ectopy

Front 21

what does PVC stand for?

Back 21

premature ventricular contractions

Front 22

what are examples of causes of PVC?

Back 22

etiologies that cause ventricular ectopy and hyperthyroidism

Front 23

hyperthyroidism can cause what?

Back 23

PVC

Front 24

how does hyperthyroidism cause PVC?

Back 24

thyroid hormone sensitizes the myocardium to the stimulatory affects of locally released norepinephrine and circulating epinephrine which may lead to substantial shortening of the spontaneous depolarization rate of all myocardial cells to the point where ventricular cell depolarizes at a faster rate than the SA node

Front 25

how frequently do individuals experience PVCs?

Back 25

some experience clinically irrelevant PVCs daily, but the frequency can be exacerbated by extrinsic events

Front 26

what is reentry?

Back 26

a mechanism of arrhythmogenesis based on abnormal impulse conduction through the myocardium

Front 27

what is arrhythmogenesis?

Back 27

development of arrhythmia

Front 28

a mechanism of arrhythmogenesis based on abnormal impulse conduction through the myocardium is called what?

Back 28

reentry

Front 29

what is the necessary conditions for reentry?

Back 29

simultaneous development of abnormally slow cell-to-cell impulse propagation, coupled with the abnormal property of unidirectional conduction

Front 30

simultaneous development of abnormally slow cell-to-cell impulse propagation, coupled with the abnormal property of unidirectional conduction are the necessary conditions for what?

Back 30

reentry

Front 31

what is the result of reentry?

Back 31

impulse that is propagated in a reentrant circuit that depolarizes the normal cardiac tissue in a regularly occuring interval

Front 32

what enables reentry to happen?

Back 32

a combination of slow and unidirectional impulse conduction in a portion of tissue, allowing the impulse to conduct in the opposite direction when it exits the abnormal tissue it will produce an action potential in the normal tissue if that tissue is not refractory at the moment of entry

Front 33

what is key to reentry occuring?

Back 33

timing; a critical timing requirement involving the exit of the impulse from the slowly conductive tissue back into the normal tissue when it is not refractory is it able to cnduct current and a reentry circuit is established

Front 34

how can reentrant arrhythmias be precipitated or abolished?

Back 34

changing autonomic tone that alters conduction velocity and some antiarrythmic drugs alter refractory period and can be used therapeutically

Front 35

what are the mechanisms of antiarrhythmic drugs?

Back 35

local anesthetics, calcium channel antagonists, cardiac glycosides, β1-adrenergic antagonists

Front 36

what are local anesthetics?

Back 36

drugs that block fast Na+ channels and are most efficacious in cardiac cells in which Na+ channels are a prominent component of depolarization

Front 37

drugs that block fast Na+ channels and are most efficacious in cardiac cells in which Na+ channels are a prominent component of depolarization are called what?

Back 37

local anesthetics

Front 38

what are examples of local anesthetics?

Back 38

lidocaine and procainamide

Front 39

lidocaine is an exampled of what type of drug?

Back 39

local anesthetics

Front 40

procainamide is an example of what type of drug?

Back 40

local anesthetics

Front 41

what are calcium channel antagonists?

Back 41

bind to slow Ca++ channels keeping them from opening, with especially prominent affects on cells of the SA and AV nodes (pacemaker cells)

Front 42

bind to slow Ca++ channels keeping them from opening, with especially prominent affects on cells of the SA and AV nodes (pacemaker cells) are called what?

Back 42

calcium channel antagonists

Front 43

where do calcium channel antagonists have the most prominent affects?

Back 43

cells of the SA and AV nodes

Front 44

what cells do calcium channel antagonists have the most prominent affect on?

Back 44

pacemaker cells

Front 45

what is an example of a calcium channel antagonist?

Back 45

diltiazem

Front 46

diltiazem is an example of what type of drug?

Back 46

calcium channel antagonist

Front 47

what are cardiac glycosides?

Back 47

inhibit cell membrane bound Na+/K+ pump because the action of pumping Na+ out of cardiac cells indirectly supplies energy to a Na+(in)/Ca++(out) exchange that transports Ca++ out of the cells so that inhibiion of the ATPase influences the RMP in a manner that helps supress ectopy and slows AV conduction

Front 48

inhibit cell membrane bound Na+/K+ pump because the action of pumping Na+ out of cardiac cells indirectly supplies energy to a Na+(in)/Ca++(out) exchange that transports Ca++ out of the cells so that inhibiion of the ATPase influences the RMP in a manner that helps supress ectopy and slows AV conduction is called what?

Back 48

cardiac glycosides

Front 49

what is an example of a cardiac glycoside?

Back 49

digitalis preperations

Front 50

digitalis preperations are examples of what type of drug?

Back 50

cardiac glycosides

Front 51

what are β1-adrenergic antagonists?

Back 51

reverse or prevent the action of catecholamines as enhancers of depolarization and impulse conduction

Front 52

what is another name for β1-adrenergic antagonists?

Back 52

beta blockers

Front 53

what are beta blockers?

Back 53

β1-adrenergic antagonists?

Front 54

what is an example of a β1-adrenergic antagonists?

Back 54

atenolol

Front 55

atenolol are examples of what type of drug?

Back 55

β1-adrenergic antagonists?