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Antiarrhythmic agents
Learning objectives
Upon completion of this chapter, you should be able to:
1.
Describe the cardiac action potential and its phases to explain the changes made by each class of
antiarrhythmic agents.
2.
Describe the therapeutic actions, indications, pharmacokinetics, contraindications and cautions, most
common adverse reactions and important drug–drug interactions associated with antiarrhythmic agents.
3.
Discuss the use of antiarrhythmic agents across the lifespan.
4.
Compare and contrast the prototype antiarrhythmic drugs lignocaine, propranolol, amiodarone and diltiazem
with other agents in their class and with other classes of antiarrhythmics.
5.
Outline the care considerations, including important teaching points, for people receiving antiarrhythmic
agents.
Glossary of key terms
antiarrhythmics:
drugs that affect the action potential of cardiac cells and are used to treat arrhythmias and restore normal rate
and rhythm
bradycardia:
slower-than-normal heart rate (usually less than 60 beats/minute)
Cardiac Arrhythmia Suppression Trial (CAST):
a large research study run by the US National Heart and Lung Institute found that
long-term treatment of arrhythmias may have a questionable effect on mortality, and in some cases actually lead to increased
cardiac death; basis for the current indication for antiarrhythmics (short-term use to treat life-threatening ventricular arrhythmias)
cardiac output:
the amount of blood the heart can pump per beat; influenced by the coordination of cardiac muscle contraction,
heart rate and blood return to the heart
haemodynamics:
the study of the forces moving blood throughout the cardiovascular system
heart blocks:
blocks to conduction of an impulse through the cardiac conduction system; can occur at the atrioventricular node,
interrupting conduction from the atria into the ventricles, or in the bundle branches within the ventricles, preventing the normal
conduction of the impulse
premature atrial contraction (PAC):
caused by an ectopic focus in the atria that stimulates an atrial response
premature ventricular contraction (PVC):
caused by an ectopic focus in the ventricles that stimulates the cells and causes an early
contraction
proarrhythmic:
tending to cause arrhythmias; many of the drugs used to treat arrhythmias have been found to generate them
tachycardia:
faster-than-normal heart rate (usually greater than 100 beats/minute)
Test your current knowledge of antiarrhythmic agents with a PrepU Practice Quiz!
ANTIARRHYTHMIC AGENTS
Class I antiarrhythmics
Class Ia
disopyramide
Class Ib
lignocaine
Class Ic
flecainide
propafenone
Class II antiarrhythmics
esmolol
propranolol
Class III antiarrhythmics
amiodarone
sotalol
Class IV antiarrhythmics
diltiazem
verapamil
Other antiarrhythmics
adenosine
digoxin
