they remain benign. Antiarrhythmia medications
successfully treat the majority of symptomatic
arrhythmias. These medications work by blocking
certain aspects of the biochemical functions
responsible for myocardial contractions. The cardi-
ologist may prescribe two or more antiarrhythmia
medications in combination to treat some kinds of
arrhythmias. People who have heart failure, CAD,
valvular disease, and other heart disorders may
take antiarrhythmia medications along with other
medications to treat these conditions.
Cardiologists select antiarrhythmia medications
based on the characteristics of the arrhythmia,
which may be simple or complex, as well as the
presence of other cardiovascular conditions, any
other medications the person may be taking, and
factors such as age and lifestyle. After starting
antiarrhythmia therapy, it is important to con-
tinue until the cardiologist makes changes in the
therapeutic approach. Suddenly stopping an
antiarrhythmia medication can have significant
consequences including serious arrhythmias.
Antiarrhythmia medications can have serious
side effects such as worsening the existing
arrhythmia or causing new arrhythmias. Some
medications work by causing heart block, for
example, to interrupt the conduction of aberrant
electrical impulses. Finding the right medication
or combination of medications sometimes takes a
period of trial regimens and dosages. As the condi-
tion responsible for the arrhythmia changes over
time, sometimes it becomes necessary to change
the medication regimen as well.
Other interventions may become necessary if
medications are ineffective or generate intolerable
side effects. Such interventions may include- CARDIOVERSION, in which the cardiologist deliv-
ers (under sedation) a mild electrical shock
through the chest wall to reorganize and
restore to normal the heart’s electrical activity - RADIOFREQUENCY ABLATION, a cardiac catheteriza-
tion procedure in which the cardiologist uses
radiofrequency impulses to kill a small and
carefully targeted segment of myocardial cells
to prevent them from initiating or conveying
electrical impulses - implantable PACEMAKER, a small battery-oper-
ated device that emits an electrical impulse to
trigger the heart’s contractions
18 The Cardiovascular System
COMMONLY PRESCRIBED ANTIARRHYTHMIA MEDICATIONSBeta Blockers
acebutolol (Sectral) atenolol (Tenormin) betaxolol (Kerlone)
carteolol (Cartrol) esmolol (Brevibloc) labetalol (Normodyne)
metoprolol (Lopressor) nadolol (Corgard) penbutolol (Levatol)
pindolol (Visken) propranolol (Inderal) sotalol (Betapace)
timolol (Blocadren)
Calcium Channel Blockers
amlodipine (Norvasc) bepridil (Vascor) diltiazem (Cardizem)
felodipine (Plendil) isradipine (DynaCirc) nicardipine (Cardene)
nifedipine (Procardia) nimodipine (Nimotop) nisoldipine (Sular)
verapamil (Isoptin)
Miscellaneous Actions
adenosine digoxin
Potassium Channel Blockers
amiodarone (Cordarone) dofetilide (Tikosyn) ibutilide (Corvert)
Sodium Channel Blockers
disopyramide (Norpace) flecainide (Tambocor) lidocaine (Xylocaine)
mexiletine (Mexitil) moricizine (Ethmozine) procainamide (Procan)
propafenone (Rythmol) quinidine (Cardioquin) tocainide (Tonocard)