Antiarrhythmeics

Question 1

In all arrhythmias

Answer 1

some facet of the normal
electrophysiologic system that governs cardiac
contraction is behaving abnormally

Question 2

Fibrillations =

Answer 2

uncoordinated contractions (400 – 700
bpm)

Question 3

Flutters =

Answer 3

all areas may not follow normally (can affect
atria or ventricles); atrial flutter (300 bpm); often involves
re-entry

Question 4

Heart block =

Answer 4

– complete = His Purkinje system cut in half; therefore atria and ventricles work independently

– partial = some areas affected more than others

Question 5

Antiarrhythmic Medications Pharmacologic Effects:

Answer 5

– Change of slope of depolarization
– Raise threshold for depolarization
– Alter conduction velocity in different parts of the
heart

Question 6

What drives automaticity?

Answer 6

Spontaneous opening and closing of K+

channels.

Question 7

Is there ever a time when we want to induce an arrhythmia?

Answer 7

– Ventricular arrhythmias due to AV node block
– For temporary heart block until pacemaker
insertion

Question 8

– IA Antiarrhythmic drugs

Answer 8

slow conduction, prolong AP, increase ERP

reversible lupus-like
syndrome in 25% of patients

Question 9

What is disopyramide (Norpace) class and effect?

Answer 9

Class IA
slow conduction, prolong AP, increase ERP

 Used for treatment of ventricular
arrhythmias, as an alternative to quinine and
procainamide

Question 10

amiodarone (Cordarone, Pacerone) adverse affects

Answer 10

Contains iodine = long-term use causes blue skin
discoloration due to accumulation of iodine

– May cause thyroid disease with long-term use

– Severe toxic effects = compliance is very poor;
many patients opt to discontinue the drug
 Pulmonary fibrosis, GI tract intolerance, tremor,
ataxia, neuropathy, liver toxicity, photosensitivity,
muscle weakness

Question 11

amiodarone (Cordarone, Pacerone) treats?

Answer 11

Life-threatening recurrent ventricular fibrillation

and/or if refractory or intolerant of other antiarrhythmics

Question 12

Digoxin** use

Answer 12

for the treatment of congestive heart failure and
to slow the ventricular rate in tachyarrhythmias such as
atrial fibrillation, atrial flutter, and supraventricular
tachycardia (paroxysmal atrial tachycardia);
cardiogenic shock

atrial fibrillation and flutter