The need for treatment of arrhythmias depends on the symptoms and the seriousness of the arrhythmia. Treatment is directed at causes. If necessary, direct antiarrhythmic therapy, including antiarrhythmic drugs, cardioversion-defibrillation , implantable cardioverter-defibrillators ICDs , pacemakers and a special form of pacing, cardiac resynchronization therapy , catheter ablation , surgery , or a combination, is used. Most antiarrhythmic drugs are grouped into 4 main classes Vaughan Williams classification based on their dominant cellular electrophysiologic effect see table Antiarrhythmic Drugs Vaughan Williams Classification.
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Antiarrhythmic drugs are those that act upon the electrical conduction system of the heart in an attempt to maintain sinus rhythm. They are classified by the Vaughan-Williams classification system as below:.
While class IA drugs are effective to treat atrial fibrillation , they are not commonly utilized for this purpose due to side-effects and significant pro-arrhythmia except in special situations. Procainamide can cause drug-induced lupus erythematosus detected by measuring anti-histone antibodies.
It is used to treat atrial fibrillation when Wolff-Parkinson-White syndrome is present and can cause drug-induced lupus erythematosus. Disopyramide is used in vagally mediated atrial fibrillation and in hypertrophic obstructive cardiomyopathy. Quinidine is rarely used and causes cinchonism. Amiodarone has more class III properties than class I and is used primarily for atrial fibrillation and ventricular tachycardia.
Amiodarone toxicity is a concern. Lidocaine is used intravenously to treat ventricular tachycardia and ventricular fibrillation. Lidocaine toxicity can occur at higher doses. Mexiletine is available orally to treat ventricular tachycardia. Tocainide is no longer used. The class IC drugs are commonly used to maintain sinus rhythm in atrial fibrillation patients.
Significant coronary artery disease is a contraindication to their use as this increases the risk of proarrhythmia and sudden cardiac death. These agents must be used in combination with an AV blocking agent in order to prevent rapid atrial fibrillation or atrial flutter conduction conduction through the AV node resulting in very fast ventricular rates if a breakthrough episode occurs since class IC drugs also act to increase AV nodal conduction.
If documented to be successful and safe while hospitalized, flecainide can be used on an as-needed basis in the outpatient setting. Note that propafenone is hepatically cleared not recommended with liver disease while flecainide is renally cleared. Encainide and moricizine are rarely used. These drugs are known as beta-blockers.
They antagonize beta-receptors inhibiting the effect of the sympathetic nervous system resulting in decreased chronotropy heart rate , inotropy contractility and dromotropy conductivity. The class III drugs are used to treat primarily atrial fibrillation, however amiodarone is FDA approved only for the treatment of ventricular tachycardia. Amiodarone is very effective however amiodarone toxicity is a concern.
The half-life of amiodarone is 42 days. Amiodarone and dofetilide are preferred in patients with left ventricular systolic dysfunction reduced ejection fraction. Dronedarone is not safe with systolic heart failure or in the setting of permanent atrial fibrillation. Bretylium is rarely used. Ibutilide can be used as a one time intravenous infusion to cardiovert atrial fibrillation to sinus rhythm chemically. These drugs are known as non-dihydropyridine calcium channel blockers and act by blocking cardiac calcium uptake.
They are used to slow AV nodal conduction decreasing heart rate. They have less of an effect on sinus node activity. Tell us what you think about Healio. Patient Information What is Hypertension?
What is Atrial Fibrillation? Visit Healio. They are classified by the Vaughan-Williams classification system as below: Class IA drugs : Quinidine , Amiodarone , Procainamide , Disopyramide These drugs block cardiac sodium channels and depress phase 0 of the action potential. Class IB drugs : Lidocaine , Mexiletine , Tocainide These drugs block cardiac sodium channels and shorten the action potential.
Class IC drugs : Flecainide , Propafenone, Encainide , Moricizine These drugs block cardiac sodium channels and has no effect on the action potential. Class IV drugs : Verapamil, Diltiazem These drugs are known as non-dihydropyridine calcium channel blockers and act by blocking cardiac calcium uptake.
Class V drugs : Those for whom the mechanism of action is unknown. By Steven Lome. Previous Next. Follow Healio. Sign Up for Email Get the latest news and education delivered to your inbox Email address. Account Information.
Drugs for Arrhythmias
When taken exactly as prescribed, medications can do wonders. They can also prevent complications and slow the progression of coronary heart disease. Some of the major types of commonly prescribed cardiovascular medications used to treat arrhythmias are summarized in this section. It's important to discuss all of the drugs you take with your doctor and understand their desired effects and possible side effects. Never stop taking a medication and never change your dose or frequency without first consulting your doctor. These may be given intravenously in an emergency situation or orally for long-term treatment.
A Guide to Drugs for Arrhythmia
In many cases, the arrhythmia may not be serious or require any treatment at all. However, if your doctor finds that the arrhythmia could lead to more serious heart problems, they may prescribe medication. Several types of medication can help control or resolve an arrhythmia. Antiarrhythmic drugs may be prescribed if you have tachycardia fast heart rate or premature or extra heartbeats. These medications work to correct the rhythm of your heart. They restore a normal heart rhythm by changing the electrical current that makes your heart beat.