Antiarrhythmic medication

Antiarrhythmic Medication

Antiarrhythmic medications are a class of drugs used to treat and prevent abnormal heart rhythms, known as arrhythmias. These medications work by modifying the electrical impulses in the heart, thereby restoring normal rhythm and improving cardiac function.

Classification

Antiarrhythmic drugs are classified into four main classes based on their mechanism of action, as described by the Vaughan Williams classification:

• Class I: Sodium Channel Blockers

 * Class IA: Moderate sodium channel blockade (e.g., Quinidine, Procainamide)
 * Class IB: Weak sodium channel blockade (e.g., Lidocaine, Mexiletine)
 * Class IC: Strong sodium channel blockade (e.g., Flecainide, Propafenone)

• Class II: Beta Blockers

 * These drugs reduce sympathetic activity on the heart (e.g., Propranolol, Metoprolol).

• Class III: Potassium Channel Blockers

 * These drugs prolong repolarization (e.g., Amiodarone, Sotalol).

• Class IV: Calcium Channel Blockers

 * These drugs slow conduction through the AV node (e.g., Verapamil, Diltiazem).

Mechanism of Action

Antiarrhythmic drugs work by altering the electrical conduction system of the heart. They can affect the action potential of cardiac cells by:

• Modifying ion channel activity (sodium, potassium, calcium)
• Altering autonomic nervous system input
• Changing the refractory period of cardiac tissue

Indications

Antiarrhythmic medications are used to treat various types of arrhythmias, including:

• Atrial fibrillation
• Atrial flutter
• Ventricular tachycardia
• Ventricular fibrillation
• Supraventricular tachycardia

Side Effects

While effective, antiarrhythmic drugs can have significant side effects, including:

• Proarrhythmia (inducing new arrhythmias)
• Bradycardia (slow heart rate)
• Hypotension (low blood pressure)
• Gastrointestinal disturbances
• Neurological effects (e.g., dizziness, confusion)

Monitoring and Management

Patients on antiarrhythmic medications require careful monitoring, including:

• Regular electrocardiogram (ECG) checks
• Monitoring of blood levels for certain drugs (e.g., Digoxin)
• Assessment of renal and hepatic function

Also see

• Cardiac electrophysiology
• Heart failure
• Cardiovascular pharmacology
• Electrocardiography

Cardiovascular disease A-Z

Most common cardiac diseases

• Cardiac arrhythmia‎
• Cardiogenetic disorders‎
• Cardiomegaly‎
• Cardiomyopathy‎
• Cardiopulmonary resuscitation‎
• Chronic rheumatic heart diseases‎
• Congenital heart defects‎
• Heart neoplasia‎
• Ischemic heart diseases‎
• Pericardial disorders
• Syndromes affecting the heart‎
• Valvular heart disease‎

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

A

• Accelerated idioventricular rhythm
• Acute decompensated heart failure
• Arteriosclerotic heart disease
• Athletic heart syndrome
• Atrial flutter
• Atrioventricular fistula
• Cardiovascular disease in Australia
• Autoimmune heart disease

B

• Brown atrophy of the heart

C

• Ebb Cade
• Cardiac allograft vasculopathy
• Cardiac amyloidosis
• Cardiac asthma
• Cardiac tamponade
• Cardiogenic shock
• Cardiogeriatrics
• Cardiorenal syndrome
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• Cœur en sabot
• Coxsackievirus-induced cardiomyopathy

D

• Duke Treadmill Score
• Duroziez's disease

E

• Eisenmenger's syndrome
• Embryocardia
• Endocardial fibroelastosis
• Eosinophilic myocarditis

H

• Heart attack
• Heart failure
• Heart failure with preserved ejection fraction
• Heart to Heart (1949 film)
• High-output heart failure
• Hyperdynamic precordium

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

I

• Idiopathic giant-cell myocarditis
• Interventricular dyssynchrony
• Intraventricular dyssynchrony
• Isolated atrial amyloidosis

K

• Keshan disease

L

• Loeffler endocarditis

M

• Mydicar
• Myocardial bridge
• Myocardial disarray
• Myocardial rupture
• Myocardial scarring
• Myocardial stunning
• Myocarditis

N

• Nonbacterial thrombotic endocarditis

O

• OLR1
• Ostial disease

P

• Papillary fibroelastoma
• Pathophysiology of heart failure
• Postpericardiotomy syndrome
• Pulmonary vein stenosis

R

• Right axis deviation
• Roemheld syndrome

S

• Saturated fat and cardiovascular disease
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• Strain pattern
• Subacute bacterial endocarditis
• Sudden cardiac death of athletes

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T

• Traumatic cardiac arrest

V

• Ventricular aneurysm
• Vibroacoustic disease
• Viral cardiomyopathy

W

• Waon therapy