Management of Atrial Fibrillation

Definition A supraventricular tachyarrhythmia Characterized by Uncoordinated atrial activation Deterioration of atrial mechanical function

ECG No consistent P waves Rapid oscillations or fibrillatory waves that vary in size, shape, and timing, Irregular, frequently rapid ventricular response when AV conduction is intact.

Ventricular Response Electrophysiological properties of the AV node depends on Electrophysiological properties of the AV node The level of vagal and sympathetic tone The action of drugs

Variation Regular RR intervals are possible in the presence of AV block or interference due to ventricular or junctional tachycardia

Special Situation In patients with electronic pacemakers, diagnosis of AF may require temporary inhibition of the pacemaker to expose atrial fibrillatory activity

Special Situation A rapid, irregular, sustained, wide-QRS-complex tachycardia strongly suggests AF with conduction over an accessory pathway or AF with underlying bundle-branch block. Extremely rapid rates (over 200 bpm) suggest the presence of an accessory pathway.

Related Arrhythmias Atrial flutter or atrial tachycardia Other atrial tachycardias AV reentrant tachycardias AV nodal reentrant tachycardias

Atrial Flutter May arise during treatment AF May degenerate into AF May be initiated by AF ECG pattern may alternate between atrial flutter and AF

Atrial Flutter More organized arrhythmia Saw-tooth pattern of regular atrial activation, particularly in leads II, III, and aVF Without an isoelectric baseline between deflections

Untreated Atrial Flutter Typical atrial rate 240-320 bpm ƒ waves Inverted in ECG leads II, III, and aVF Upright in lead V1 Wave of activation in the right atrium may be reversed

Ventrivular Response of Atrial Flutter Commonly occurs with 2:1 AV block Resulting in a ventricular rate of 120- 160 bpm Most characteristically about 150 bpm

A unique type of atrial tachycardia has recently been identified that commonly originates in the pulmonary veins but may arise elsewhere, is rapid (typically faster than 250 bpm), and often degenerates into AF.

Clinical Evaluation Minimum Evaluation Additional Investigation Clinical History and Physical Examination Investigations Additional Investigation Holter Monitoring and Exercise Testing Transesophageal Echocardiography Electrophysiological Study

Proposed Management Strategies

Newly Discovered AF

Recurrent Paroxysmal AF

Recurrent Paroxysmal AF

Recurrent Persistent AF & Permanent AF

Agents With Proven Efficacy Amiodarone Dofetilide Flecainide Ibutilide Propafenone Quinidine

Less Effective or Incompletely Studied Agents Beta-Blockers Calcium Channel Antagonists Digoxin Disopyramide Procainamide Sotalol