Antiarrhythmic

Question 1

drugs to use for Afib?

Answer 1

beta blockers to lower HR and promote sinus rhythm

anticoag therapy to prevent stroke

Question 2

superventricular tachycardia tx with what?

Answer 2

propanolol, verapamil, or digoxin, these slow conduction through AV node

Question 3

ventricular tachy: requires prompt management tx with what?

ventricular fib tx with with what?

Answer 3

lidocaine
amiodiorne

epi

Question 4

MCC of arrhythmia?

Answer 4

impulse conduction (unidirectional block can cause reentry)

Question 5

many antiarrhythmic agents have proarrhythmic actions meaning they what?

Answer 5

cause arrhythmias!!!

Question 6

IA:

Answer 6

NA channel blocker

slows phase 0 depolar in ventricualr muscle fibers

Question 7

IB:

Answer 7

NA channel blocker

shortens phase 3 repolarization in ventricular muscle fibers

Question 8

IC:

Answer 8

NA channel blocker

markedly slows phase 0 depolarization in ventricular muscle fibers

Question 9

II:

Answer 9

B adrenoreceptor blocker

inhibits phase 4 depolarization in SA and AV nodes

Question 10

III:

Answer 10

K channel blocker

prolongs phase 3 repolarization in ventricular muscle fibers

Question 11

IV:

Answer 11

Ca channel blocker

inhibits action potential in SA/AV nodes

Question 12

Quinidine:

class?

Answer 12

1A

high doses can lead to V fib

inhibits ectopic/ventricular arrthymias

prevents reentry arrhythmias

Question 13

uses of quinidine?

Answer 13

Arrythmias: atrial, AV junctional, v tach

maintain sinus rhythm

Question 14

ADR/DDI of Quinidine?

Answer 14

worsen arrhythmia, SA/AV block, can induce v tach

decreases digoxin renal clearance, increases digoxin concentrations

Question 15

Procainamide:

class?

ADR?

Answer 15

1A

similar to quinidine

reversible SLE like syndrome

high concentration can cause asystole/v arrhytmias

depression, hallucination, psychosis

Question 16

Disopyramide:

class?
ADR?
CI?

Answer 16

1A

similar to quinidine
causes peripheral vasoconstriction

used as alternative to procainimide/quinidine for v arrhtyhmias

Anticholinergic: dry mouth, uriniary retention

CI in pts with HF

Question 17

Lidocaine:

class?
drug of choice for what?

actions?

Answer 17

1B

cardiac arrhythmias

shortens Phase 3
suppresses arrhytmias caused by abnormal automaticity
prevents reentry arrhythmias (bidirectional block)

Question 18

Lidocaine:

uses?
how is it given?

ADR:

Answer 18

V arrhythmia from ischemias (MI)

does not slow conduction

given IV

CNS effects: drowsy, paresthsia, confusion, slurred speech

can cause arrhythmias

Question 19

Mexiletine: class? use?

Tocainide: class? use?

Answer 19

1B (both given orally)

chronic Ventricular arrythmias with MI

1B

tx of tachyarrhythmias

pulm toxic can lead to fibrosis

Question 20

class 1C is approved only for what?

Flecainide: class?

actions?

Answer 20

REFRACTORY VENTRICULAR ARRHYTHMIAS

1C

suppresses phase 0 upstoke in purkinje and myocardial fibers, markedtly slowing of conduction in all cardiac tissue

Question 21

Flecainide: use? how is it taken?

ADR:

Answer 21

refractory arrhythmias

orally

aggravate CHF
N/dizziness
aggravate preexisting arrhythmias, indice life threatening v tach that is resistant to tx

Question 22

Propafenone: class?

Answer 22

1C

similar to flecainide

broad spectrum antiarrhythmic agent

Question 23

Class 2:

what do they do?

useful in?

Answer 23

B adrenergic antagonists

diminish phase 4 depolarization in SA/AV node

reducing mortality with acute MI

useful in tachyarrhythmias, a flutter/fib

Question 24

Class 2 drugs:

Answer 24

propanolol-reduces sudden death after MI

metoprolol-reduces risk of bronchospasm

esmolol-short acting for acute arrhythmias during surgery/emergency

Question 25

class 3: blocks what? what can all class 3 drugs induce?

Answer 25

potassium channels can induce arrhythmias

Question 26

Amiodarone: class? prolonged what? does not what? uses: ADR:

Answer 26

III half life, several weeks to work prolong QT interval severe refractory supraventricular/ventriular tachyarrhythmias preferred antiarrhythmic in pts with HF very toxic, 50% discontinue from ADRS pulmonary fibrosis, GI intolerance, tremor, ataxia, muscle weakness, hyper/hypo thyroidism, liver toxic, BLUE SKIN DISCOLORATION DUE TO ACCUMULATION OF IODINE

Question 27

Sotalol: class? has potent what? uses: ADRs:

Answer 27

III B blocking activity antifibrillary effects preventing recurrence of arrhythmia and decreasing mortality in pts with sustained v tach prolongs QT-torsades lowest rate of acute or long term effects

Question 28

Dodetilide: class? used in pts with what? risk of what? must complete what?

Answer 28

III persisten a fib/HF/CAD w/ impaired LV function proarrhythmia perscribers must complete training

Question 29

class IV: decreases rate of what? slows what? major effects on what?

Answer 29

CCB decreases rate of phase 4 slows conduction in AV node major effects on vascular/smooth muscle

Question 30

CCB: more effective when? uses? ADRS? Verapamil, diltiazem

Answer 30

heart beating rapidly atrial dysrhythmias HTN/angina hypotension, edema, negative inotropic properties

Question 31

Digoxin: class? shortens what in atrial/ventricular myocardial cells? prolongs refractory period and slows conduction in what? used for what? narrow what?

Answer 31

IV refractory period purkinje fibers control ventricular response rate in a fib/flutter therapuetic index (at toxic concentration causes ectopic ventricular beats, v tach/fibrillation

Question 32

Adenosine: class? decreases what? prolongs what? what does it do to the automaticity in AV node? uses? duration of action?

Answer 32

IV conduction velocity refractory period decreases supraventricualr tachycardia very short duration of action chemical cardioverter