Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

HLST220: Pharmacology > Chapter 52: Antidysrhythmic Drugs > Flashcards

Chapter 52: Antidysrhythmic Drugs Flashcards

1
Q

what is an dysrhythmia

A
  • abnormality in the rhythm of the heartbeat
  • arises from electrical impulse formation disturbances
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

pathway of conduction of electrical impulses in a heathy hear

A

SA –> atria –> AV –> ventricles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

sinoatrial (SA) node

A

pacemarker of the heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Atrioventricular (AV) node

A
  • slow enough to allow ventricles to fill with blood
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

His-Purkinje system

A

rapid ejection of blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

fast potentials occur

A

in fibers of the His-Purkinje and the atrial and ventricular muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what are the 5 phases of fast potentials

A

phase 0: depolarization
phase 1: (partial) depolarization
phase 2: plateau
phase 3: repolarization
phase 4: stable potential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

slow potentials occur

A

in the SA and AV node

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Phases of slow potentials

A

Phase 0: slow depolarization (mediated by calcium influx)
Phase 1: absent
phase 2 and 3: not significant
phase 4: depolarization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

P wave

A

depolarization in the atria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

QRS complex

A

depolarization of the ventricles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

T wave

A

repolarization of the ventricles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what are the 2 fundamental causes of dysrhythmias

A
  • disturbances of automaticity
  • disturbances of conductions (AV block, reentry)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what are antidysrhythmic drugs classified by

A

Vaughan Williams classification

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Class I

A

sodium channel blockers
- slow impulse conduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Class II

A

beta blockers
- depress depolarization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Class III

A

Potassium channel blockers
- delay repolarization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Class IV

A

Calcium channel blockers
- similar to beta blockers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Antidysrhythmic drugs should be used only when

A

dysrhythmias are symptomatically significant and only when the potential benefits clearly outweigh the risks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Prodysrhythmic effects of antidysrhythmic drugs

A
  • prolongation of the QT interval
  • Torsades de pointes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Supraventricular dysrhythmias

A

Impulse arises above the ventricle
- atrial fibrilation
- atrial flutter
- sustained supraventricular tachycardia (SVT)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Ventricular dysrhythmias

A
  • sustained ventricular tachycardia
  • ventricular fibrilation
  • premature ventricular complexxes
  • digoxin induced ventricular dysrhythmias
  • torsades de pointes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

example of class IA agents

A

Quinidine
- Procainamide (procan)
- Disopyramide (Norpace)

24
Q

Quinidine effects on the heart

A
  • blocks sodium channel blockers
  • slows impulse conduction
  • delays repolarization
  • blocks vagal input to the heart
25
Q

Quinidine effects on ECG

A
  • widens the QRS complex
  • prolongs QT interval
26
Q

Quinidine therapeutic uses

A
  • used for supraventricular and ventricular dysrhythmias
27
Q

Quinidine side effects

A
  • diarrhea, hypersensitivity, carditoxicity
28
Q

Class IB agents examples

A

Lidocaine [Xylocaine]
- mexiletine
- phenytoin

29
Q

Lidocaine [Xylocaine] effects on the heart

A
  • blocks sodium channels (slows conduction)
  • reduces automaticity in the ventricles and His-Purkinje system (accelerates repolarization)
30
Q

Lidocaine [Xylocaine] is used for

A

ventricular dysrhythmias

31
Q

Lidocaine [Xylocaine] side/adverse effects

A
  • drowsiness
  • confusion
  • paresthesia
  • toxic doses produce seizures and respiratory arrest
32
Q

Lidocaine [Xylocaine] administration

A

IV use only
- rapid hepatic metabolism

33
Q

Class IC agents

A
  • block cardiaac sodium channels
  • delay ventricular repolarization
34
Q

all class IC agents negative effects

A
  • exacerbate existing dysrhythmias and create new ones
35
Q

what are the two class IC agents

A
  • Flecainide [Tambocor]
  • Propafenone [Rhythmol]
36
Q

what are the main beta blockers used to treat dysrhythmias

A
  • propranolol [inderal]
  • Acebutolol [Sectral]
  • Sotalol [Sotacor]
  • Bidoprolol [Monocor]
37
Q

Propranolol [Inderal] effects on the heart

A
  • decreased automacity of the SA node
  • decreased velocity of conduction through AV node
  • decreased myocardial contracility
38
Q

Propranolol therapeutic use

A
  • dysrhythmias caused by excessive sympathetic stimulation
  • supra ventricular tachydysrhythmias (suppression of excessive discharge, slowing of ventricular rate)
39
Q

Amiodarone [Cordarone] therapeutic uses

A

life threatening ventricular dysrhythmias only

40
Q

Amiodarone [Cordarone] effects on the heart

A
  • reduced automaticity in the SA node; contracilirty; reduced conduction velocity
  • QRS widening; prolongation of PR and QT intervals
41
Q

Amiodarone [Cordarone] toxicity

A
  • protracted half life (25-110 days)
  • pulmonary toxicity
  • cardiotoxicity
  • toxicity in pregnancy and breat feeding
  • corneal microdeposits
  • optic neuropathy
  • liver toxicity
42
Q

Amiodarone [Cordarone] adverse effects

A
  • photosensitivity
  • skin discoloration
  • GI upset
  • thyroid toxicity
43
Q

Amiodarone [Cordarone] loading dose

A

6 weels

44
Q

Amiodarone [Cordarone] drug interactions

A
  • Quinidine
  • Diltiazem
    ‘- cyclosporine
  • digoxin
  • procainamide
  • diltiazem
  • phenytoin
  • warfarin
  • Lovastatin, simvastatin, atorcastatin
45
Q

Amiodarone levels can be increased by

A

grapefruit juice and inhibirots of CTP3A4

46
Q

Amiodarone levels can be reduced by

A

Cholestyramine

47
Q

(potassium channel blockers) the risk of severe dysrhythmias is increased by

A

diuretics

48
Q

combining amiodarone with a beta blocker, verapamil, or diltiazem can lead to

A

excessive slowing of the heart

49
Q

Calcium channel blockers examples

A
  • Verapamil [Isoptin]
  • Diltiazem [Cardizem]
50
Q

calcium channel blockers effects

A
  • reduce Sa modal automaticity
  • delay AV nodal conduction
  • reduce myocardial contractility
51
Q

calcium channel blockers therapeutic uses

A
  • slow ventricular rate (atrial fibrillation or atrial flutter)
  • terminate SVT caused by an AV nodal reentrant circuit
52
Q

Adenosine [Adenocard] effects on the heart

A
  • decreases automaticity in the SA node
  • slows conduction through AV node
  • Prolongs PR interval
53
Q

Adenosine [Adenocard] therapeutic use

A

termination of paroxysmal SVT

54
Q

Adenosine [Adenocard] adverse effects

A
  • sinus bradycardia
  • dyspnea
  • hypotension
  • facial flushing
  • chest discomfort
55
Q

Digoxin is primarily used in

A

heart failure

56
Q

Digoxin is used in

A
  • heart failure
  • treat supraventricular dysrhythmias
57
Q

Digoxin [Lanoxin] adverse effects

A

Cardiotoxicity
- risk increased by hypokalemia

HLST220: Pharmacology (46 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions