Related Experiment Video
Updated: Jun 23, 2026
23:33
The WATCHMAN Left Atrial Appendage Closure Device for Atrial Fibrillation
Published on: February 28, 2012
Low-dose amiodarone for atrial fibrillation: time for a prospective study?
H R Middlekauff1, I Wiener, L A Saxon
1Department of Medicine, UCLA School of Medicine 90024-1679.
Annals of Internal Medicine
|June 15, 1992
Summary
Low-dose amiodarone effectively maintains sinus rhythm in patients with atrial fibrillation, offering a safer alternative to Class I drugs. Further large-scale studies are warranted to confirm these findings.
Area of Science:
- Cardiology
- Pharmacology
Background:
- Atrial fibrillation causes significant morbidity, making sinus rhythm restoration a key treatment goal.
- Chronic antiarrhythmic therapy is often necessary for long-term sinus rhythm maintenance.
- Class I antiarrhythmic drugs show limited efficacy and carry risks of proarrhythmia and toxicity.
Purpose of the Study:
- To evaluate the efficacy and safety of low-dose amiodarone for maintaining sinus rhythm in atrial fibrillation patients.
- To compare low-dose amiodarone with traditional Class I antiarrhythmic drugs.
Main Methods:
- Review of existing studies on low-dose amiodarone for atrial fibrillation.
- Analysis of reported rates of sinus rhythm maintenance and adverse events.
Main Results:
- Low-dose amiodarone maintains sinus rhythm in 53% to 79% of patients over a mean follow-up of 27 months.
- Amiodarone demonstrates a lower incidence of proarrhythmia and heart failure exacerbation compared to Class I drugs.
- Noncardiac side effects of amiodarone are dose-dependent, with low-dose regimens (<300 mg/d) being well-tolerated.
Conclusions:
- Low-dose amiodarone is a promising therapeutic option for atrial fibrillation management.
- Further large-scale prospective trials are recommended to validate the early use of low-dose amiodarone in atrial fibrillation.
Related Concept Videos
01:22Antiarrhythmic Drugs: Class I Agents as Sodium Channel Blockers
Class I antiarrhythmic drugs are used to treat various types of arrhythmias or irregular heart rhythms. These drugs block the sodium (Na+) channels in the cardiac cells, thereby affecting the movement of electrical impulses across the heart. Class I antiarrhythmic drugs are divided into three subgroups: Class IA, Class IB, and Class IC, each with distinct mechanisms of action and effects on the heart.
Class 1A Antiarrhythmic Drugs: These drugs work by moderately blocking sodium channels,...
Class 1A Antiarrhythmic Drugs: These drugs work by moderately blocking sodium channels,...
01:24Antiarrhythmic Drugs: Class II Agents as β-Adrenergic Blockers
Adrenergic stimulation generally impacts cardiac rate and rhythm. Specifically, stimulation of the β-adrenoceptors triggers an increase in intracellular calcium ion influx and pacemaker currents, which may cause arrhythmias. Catecholamines like adrenaline also demonstrate β2-adrenoceptor-mediated hypokalemia, impacting cardiac action potential and disrupting the normal cardiac rhythm. Class II antiarrhythmic drugs are β-adrenoceptor antagonists or β-blockers, which indirectly block calcium...
01:12Antiarrhythmic Drugs: Class III Agents as Potassium Channel Blockers
Class III antiarrhythmic drugs are a group of medications that can prolong action potentials in the heart. They achieve this by blocking potassium channels or enhancing inward currents from sodium channels. However, these drugs have a unique property of "reverse use-dependence," which is most pronounced at slower heart rates and can lead to torsades de pointes—a specific type of arrhythmia. However, it is essential to note that excessive QT interval prolongation—a measure of the heart's...
01:20Antiarrhythmic Drugs: Class IV Agents as Calcium Channel Blockers
Class IV antiarrhythmic drugs, such as verapamil and diltiazem, block calcium channels. They primarily affect the heart, slowing the conduction in calcium-dependent tissues like the SA and AV nodes. These drugs manage reentrant supraventricular tachycardia (SVT) and reduce ventricular rate in atrial flutter/fibrillation.
Verapamil, a calcium channel blocker, inhibits calcium movement across myocardial cell membranes and vascular smooth muscle. This results in the dilation of coronary and...
Verapamil, a calcium channel blocker, inhibits calcium movement across myocardial cell membranes and vascular smooth muscle. This results in the dilation of coronary and...
01:30Acute Coronary Syndrome III: Diagnostic Studies
Diagnosing acute coronary syndrome or ACS begins with a thorough patient history. Notable symptoms include central, crushing chest pain radiating to the left arm, neck, jaw, or back, along with shortness of breath, sweating (diaphoresis), nausea, vomiting, dizziness, and palpitations.It is crucial to note any history of cardiac illnesses and assess risk factors, including age, gender, smoking, hypertension, diabetes, hyperlipidemia, and a sedentary lifestyle.During physical examination, vital...
01:25Dysrhythmias VI: Management of Dysrhythmias
Dysrhythmia management involves a multifaceted approach, incorporating pharmacological treatments, medical procedures, surgical interventions, lifestyle modifications, and patient education.Pharmacological ManagementAntiarrhythmic Drugs:Class I (Sodium Channel Blockers): This class includes quinidine and procainamide, which reduce the speed of impulse conduction in the heart, stabilize the cardiac membrane, and control arrhythmias. Quinidine and procainamide are Class IA agents that prolong the...