Antiarrhythmic Flashcards
drugs to use for Afib?
beta blockers to lower HR and promote sinus rhythm
anticoag therapy to prevent stroke
superventricular tachycardia tx with what?
propanolol, verapamil, or digoxin, these slow conduction through AV node
ventricular tachy: requires prompt management tx with what?
ventricular fib tx with with what?
lidocaine
amiodiorne
epi
MCC of arrhythmia?
impulse conduction (unidirectional block can cause reentry)
many antiarrhythmic agents have proarrhythmic actions meaning they what?
cause arrhythmias!!!
IA:
NA channel blocker
slows phase 0 depolar in ventricualr muscle fibers
IB:
NA channel blocker
shortens phase 3 repolarization in ventricular muscle fibers
IC:
NA channel blocker
markedly slows phase 0 depolarization in ventricular muscle fibers
II:
B adrenoreceptor blocker
inhibits phase 4 depolarization in SA and AV nodes
III:
K channel blocker
prolongs phase 3 repolarization in ventricular muscle fibers
IV:
Ca channel blocker
inhibits action potential in SA/AV nodes
Quinidine:
class?
1A
high doses can lead to V fib
inhibits ectopic/ventricular arrthymias
prevents reentry arrhythmias
uses of quinidine?
Arrythmias: atrial, AV junctional, v tach
maintain sinus rhythm
ADR/DDI of Quinidine?
worsen arrhythmia, SA/AV block, can induce v tach
decreases digoxin renal clearance, increases digoxin concentrations
Procainamide:
class?
ADR?
1A
similar to quinidine
reversible SLE like syndrome
high concentration can cause asystole/v arrhytmias
depression, hallucination, psychosis
Disopyramide:
class?
ADR?
CI?
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
Lidocaine:
class?
drug of choice for what?
actions?
1B
cardiac arrhythmias
shortens Phase 3
suppresses arrhytmias caused by abnormal automaticity
prevents reentry arrhythmias (bidirectional block)
Lidocaine:
uses?
how is it given?
ADR:
V arrhythmia from ischemias (MI)
does not slow conduction
given IV
CNS effects: drowsy, paresthsia, confusion, slurred speech
can cause arrhythmias
Mexiletine: class? use?
Tocainide: class? use?
1B (both given orally)
chronic Ventricular arrythmias with MI
1B
tx of tachyarrhythmias
pulm toxic can lead to fibrosis
class 1C is approved only for what?
Flecainide: class?
actions?
REFRACTORY VENTRICULAR ARRHYTHMIAS
1C
suppresses phase 0 upstoke in purkinje and myocardial fibers, markedtly slowing of conduction in all cardiac tissue
Flecainide: use? how is it taken?
ADR:
refractory arrhythmias
orally
aggravate CHF
N/dizziness
aggravate preexisting arrhythmias, indice life threatening v tach that is resistant to tx
Propafenone: class?
1C
similar to flecainide
broad spectrum antiarrhythmic agent
Class 2:
what do they do?
useful in?
B adrenergic antagonists
diminish phase 4 depolarization in SA/AV node
reducing mortality with acute MI
useful in tachyarrhythmias, a flutter/fib
Class 2 drugs:
propanolol-reduces sudden death after MI
metoprolol-reduces risk of bronchospasm
esmolol-short acting for acute arrhythmias during surgery/emergency
class 3: blocks what? what can all class 3 drugs induce?
potassium channels
can induce arrhythmias
Amiodarone: class?
prolonged what?
does not what?
uses:
ADR:
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
Sotalol: class?
has potent what?
uses:
ADRs:
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
Dodetilide: class?
used in pts with what?
risk of what?
must complete what?
III
persisten a fib/HF/CAD w/ impaired LV function
proarrhythmia
perscribers must complete training
class IV:
decreases rate of what? slows what?
major effects on what?
CCB
decreases rate of phase 4
slows conduction in AV node
major effects on vascular/smooth muscle
CCB: more effective when?
uses?
ADRS?
Verapamil, diltiazem
heart beating rapidly
atrial dysrhythmias
HTN/angina
hypotension, edema, negative inotropic properties
Digoxin: class?
shortens what in atrial/ventricular myocardial cells?
prolongs refractory period and slows conduction in what?
used for what?
narrow what?
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
Adenosine: class?
decreases what?
prolongs what?
what does it do to the automaticity in AV node?
uses?
duration of action?
IV
conduction velocity
refractory period
decreases
supraventricualr tachycardia
very short duration of action
chemical cardioverter
