Atrial Fibrillation and Atrial Flutter Management

Introduction

• Atrial fibrillation and atrial flutter are common arrhythmias that require proper management to prevent complications, as recommended by the American College of Cardiology and the European Society of Cardiology 1, 2

Rate Control

• The American College of Cardiology recommends a combination of digoxin and a beta-blocker or calcium channel blocker to control heart rate at rest and during exercise (Class IIa) 2
• Beta-blockers, such as metoprolol, and non-dihydropyridine calcium channel blockers, such as diltiazem and verapamil, are recommended for rate control in hemodynamically stable patients with AF and rapid ventricular response (RVR), as suggested by the American Heart Association 3
• Digoxin is recommended for rate control in patients with AF and RVR, particularly in those with heart failure, as suggested by the American College of Cardiology and the American Heart Association 3, 2
• Amiodarone may be considered for rate control in patients with AF and RVR, particularly when other agents are unsuccessful or contraindicated, as suggested by the American Heart Association 3
• Intravenous diltiazem is the preferred calcium channel blocker for acute rate control in atrial flutter due to its safety and efficacy, as recommended by the American College of Cardiology 4
• Alternatively, intravenous beta blocker (esmolol is preferred due to rapid onset) can be used for rate control in atrial flutter 4

Rhythm Control

• Rhythm control may be preferred for younger patients, highly symptomatic patients despite adequate rate control, patients with AF-induced cardiomyopathy, and patients with first episode of AF, as suggested by the American College of Cardiology 2
• Synchronized electrical cardioversion is indicated for stable patients with well-tolerated atrial flutter when pursuing rhythm control 4
• Synchronized electrical cardioversion can be successful at lower energy levels than for atrial fibrillation 4
• Intravenous ibutilide is effective for acute pharmacological cardioversion of atrial flutter (approximately 60% success rate) 4
• Monitor for torsades de pointes for at least 4 hours after administration of intravenous ibutilide 4
• Pretreatment with magnesium can increase efficacy and reduce risk of torsades de pointes when using intravenous ibutilide 4

Anticoagulation

• The American College of Cardiology recommends evaluating the risk of stroke using the CHA₂DS₂-VASc score 2
• Anticoagulation is recommended for a CHA₂DS₂-VASc score ≥2, and should be considered for a score of 1 2
• The CHA₂DS₂-VASc score is calculated as follows:

• Direct oral anticoagulants (DOACs) are preferred over vitamin K antagonists (VKAs) except in patients with mechanical heart valves and mitral stenosis, as recommended by the European Society of Cardiology 5
• Anticoagulation should be continued regardless of whether sinus rhythm is restored, as recommended by the European Society of Cardiology 5

Postoperative Atrial Flutter

• Many postoperative atrial flutters resolve spontaneously within 3 months 4
• If temporary pacing wires are in place from cardiac surgery, rapid atrial pacing can be considered for termination of atrial flutter 4
• Ablation of atrial flutter should not be attempted immediately after surgery; defer for at least 3 months unless pharmacological therapy fails to control the arrhythmia 4

Contraindications and Precautions

• Calcium channel blockers should be avoided in patients with evidence of decompensated heart failure 3
• Beta blockers should be avoided in patients with evidence of reactive airway disease 4
• Verapamil or diltiazem should not be used in patients with known pre-excitation (Wolff-Parkinson-White) syndrome 4
• Intravenous calcium channel antagonists or beta blockers should not be administered to patients with decompensated heart failure 3, 6
• Traditional rate control medications, such as beta-blockers, calcium channel blockers, and digoxin, are contraindicated in patients with new onset atrial fibrillation with slow ventricular response as they may worsen bradycardia 7, 3
• Antiarrhythmic medications should be used cautiously, as many can worsen bradycardia, and Class I antiarrhythmics should be avoided in patients with structural heart disease 7

New Onset Atrial Fibrillation with Slow Ventricular Response

• The American Heart Association recommends assessing hemodynamic stability and obtaining a 12-lead ECG to confirm diagnosis and rule out other arrhythmias in patients with new onset atrial fibrillation with slow ventricular response 7
• Evaluation for underlying causes, including medication effects, increased vagal tone, sick sinus syndrome, AV nodal disease, hypothyroidism, and electrolyte abnormalities, is crucial in managing new onset atrial fibrillation with slow ventricular response 7
• Normalization of electrolyte abnormalities, particularly potassium and magnesium, is essential in managing new onset atrial fibrillation with slow ventricular response 7
• Atropine 0.5-1.0 mg IV may be administered for temporary increase in heart rate in patients with new onset atrial fibrillation with slow ventricular response, with a maximum dose of 3 mg 7
• Isoproterenol infusion (2-10 μg/min) or dopamine (5-20 μg/kg/min) may be considered as temporary measures while preparing for more definitive therapy in patients with new onset atrial fibrillation with slow ventricular response 7
• Temporary transvenous pacing followed by permanent pacemaker implantation is recommended for patients with persistent symptomatic bradycardia or evidence of sick sinus syndrome 7, 3