Antiarrhythmics Flashcards Preview

Dental Pharmacology > Antiarrhythmics > Flashcards

Flashcards in Antiarrhythmics Deck (66):
1

which class of drugs decreases cardiac automaticity?

B-blockers

2

which class of drugs decreases AV conduction?

Ca channel blockers

3

natural pacemaker in the heart

SA node

4

Fast AP occurs in ... and ...

purkinje fibers and muscle fibers

5

the ... is determined by the steepness of phase 0

conduction velocity (Vmax)

6

phase 2 also constitutes the ... during which another impulse cannot be generated

effective refractory period

7

the steeper the slope of phase 4, the higher the rate of ...

automaticity

8

... is the time that the cell is depolarized

action potential duration

9

... protects heart against arrhythmias

effective refractory period

10

slow AP occurs in ... and ...

SA and AV nodes

11

increased/decreased SA node firing

altered automaticity

12

abnormal generation of impulses; spontaneous depolarization in another portion of heart leading to generation of AP

ectopic pacemaker

13

a unidirectional conduction block

reentrant arrhythmia

14

Class IA: Na channel blockers

disopryamide, quinidine, procainamide

15

Class IA blockers are most effective with ...

atrial arrhythmias

16

IA blockers are myocardial depressants that reduce ... and ... and increase ...

reduce automaticity and responsiveness (Vmax) and increase ERP

17

most important Class IA Na channel blocker

disopryamide

18

Class IA Na channel blockers block ... and inhibit rabid inward Na current

rapid Na channels

19

Class IA Na channel blockers slow ... thereby abolishing ectopic foci

phase 4 depolarization (decreases automaticity)

20

Class IA Na channel blockers depress ... in slow and fact action potentials

the rate of phase 0 depolarization

21

side effects of which drug?: anticholinergic action (urinary retention, dryness of mouth, constipation); generalized cardiac depression; reduction in myocardial contractility

disopyramide

22

which class IA Na channel blocker?: IV administration only

procainamide

23

Class IB Na channel blockers

lidocaine and mexiletine

24

Class IB Na channel blocker used for ventricular arrhythmias in ICUs that arise from myocardial infarctions or digitalis toxicity

lidocaine

25

lidocaine is effective only on ... and is not effective in the treatment of atrial arrhythmias

ventricular arrhythmias

26

Lidocaine will suppress ventricular ectopic foci and will decrease ... by decreasing slope of phase 4

automaticity of purkinje fibers

27

lidocaine shortens duration of ... and ...

AP and ERP

28

Class IC Na channel blockers

flecainide and propafenone

29

Class IC Na channel blockers used for ventricular arrhythmias

propafenone

30

Class II B1 Blockers

metoprolol, acebutolol, esmolol, propranolol

31

B-blockers are utilized to treat:

arrhythmias (heart rate)

32

B1 blockers are used primarily with ...

atrial arrhythmias

33

Bl blockers reduce ... by slowing the transmission of impulses through the AV node

ventricular rate

34

B blockers will decrease ... of discharge and the conduction velocity

the SA node rate

35

primary effect of B blockers is to decrease rate of conduction through ... (increases ERP)

the AV node

36

B-blockers and ... slow conduction through AV node

verapamil

37

Class III K channel blockers

amiodarone, sotalol, dofetilide, ibutilide

38

K channel blockers prolong the AP and ERP of ...

purkinje and muscle fibers

39

what has replaced lidocaine as drug of choice in cardiac resuscitation?

IV amiodarone

40

Unlike amiodarone and sotolol, ... and ... are "pure" class III with no Class I, II or IV activity

ibutilide and dofetilide

41

Class IV Ca channel blockers

verapamil and diltiazem

42

Ca channel blockers used to treat ...

atrial arrhythmias

43

verapamil is used to reduce ventricular response to atrial flutter or fibrillation by slowing ... through AV node

conduction

44

Verapamil will depress ...

Ca dependent action potentials

45

the key effect of verapamil is to ... conduction velocity through the AV node

depress

46

Verapamil will also slow ... of SA and AV nodes

slow pacemaker activity (automaticity)

47

both verapamil and diltiazem reduce

HR, SA node automaticity, AV conduction, myocardial contractility

48

side effects of which class?: severe bradycardia stemming from AV block, depressive effect on myocardial contractility, contraindicated in patients with sick sinus syndrome, AV block and CHF

Class IV Ca channel blockers

49

verapamil and ... together may cause AV block

Bl Blockers

50

verapamil can increase blood levels of ...

digoxin

51

Adenosine is a

Ca blocker

52

elimination half life of amiodarone is ...

25 to 100 days

53

digoxin useful for atrial ..., ... or ... because it slows conduction through AV node

tachycardia, flutter or fibrillation

54

MoA: digoxin inhibits ... and increases intracellular Ca concentration

Na/K ATPase

55

Digitalis increases ...

cardiac contractility

56

direct effects of digoxin on AV node: will have increased ... and decreased conduction velocity

ERP

57

indirect effects of digoxin: will increase ... to the heart and slow HR by increasing baroreceptor firing

the vagal activity

58

MoA of digoxin is increased ... for muscle contraction and enhanced contractility

intracellular Ca availability

59

the other clinical use of digoxin is to reduce ...

atrial arrhythmias

60

side effect of digoxin increased automaticity of purkinje fibers and elevated risk of ...

ventricular arrhythmias

61

T1/2 of digoxin is ...

1.5 days

62

cardiac side effects of digoxin: abnormalities in the cardiac rhythm including ..., slowing of the heart rate and ...

AV block
Ventricular arrhythmias

63

hypercalcemia will ... digoxin effects

enhance

64

old age will ... digoxin clearance

decrease

65

hypokalemia ... sensitivity to digoxin

increases

66

myocardial infarction- digoxin should ...

not be used