Management of Atrial Fibrillation
For most patients with atrial fibrillation, initiate rate control with a beta-blocker or non-dihydropyridine calcium-channel blocker combined with oral anticoagulation based on CHA₂DS₂-VASc score—this approach equals rhythm control for mortality and cardiovascular outcomes while causing fewer adverse effects. 1, 2
Immediate Hemodynamic Assessment
Perform immediate synchronized electrical cardioversion without awaiting anticoagulation if the patient presents with:
- Hypotension or shock 1, 2
- Acute heart failure or pulmonary edema 1, 2
- Ongoing chest pain or myocardial infarction 1, 2
- Altered mental status 2
If hemodynamically stable, proceed to rate control and stroke-risk assessment. 1, 2
Stroke Prevention & Anticoagulation
Risk Stratification
Calculate the CHA₂DS₂-VASc score immediately:
- Congestive heart failure (1 point) 2
- Hypertension (1 point) 2
- Age ≥75 years (2 points) 2
- Diabetes (1 point) 2
- Prior stroke/TIA/thromboembolism (2 points) 2
- Vascular disease (1 point) 2
- Age 65–74 years (1 point) 2
- Female sex (1 point) 2
Anticoagulation Decisions
Initiate oral anticoagulation for all patients with CHA₂DS₂-VASc ≥2 (men) or ≥3 (women). 2
Prescribe a direct oral anticoagulant (apixaban, dabigatran, edoxaban, or rivaroxaban) as first-line therapy over warfarin, except in patients with mechanical heart valves or moderate-to-severe mitral stenosis. 2
If warfarin is required, target INR 2.0–3.0 with weekly monitoring during initiation and monthly monitoring once stable. 1, 2
Continue anticoagulation indefinitely based on stroke risk, regardless of whether sinus rhythm is restored—72% of strokes in the AFFIRM trial occurred in patients who had stopped anticoagulation or had subtherapeutic INR. 2
Rate Control Strategy
Patients with Preserved Ejection Fraction (LVEF >40%)
Use intravenous beta-blockers (metoprolol 2.5–5 mg IV over 2 minutes, repeat every 5 minutes up to three doses) or non-dihydropyridine calcium-channel blockers (diltiazem 0.25 mg/kg IV over 2 minutes) as first-line agents. 1, 2, 3
Beta-blockers are preferred in:
Diltiazem is preferred when:
- Rapid rate control is essential (faster onset than metoprolol) 3
- Chronic obstructive pulmonary disease or active bronchospasm contraindicate beta-blockers 1, 3
Target a lenient resting heart rate <110 bpm initially; pursue stricter control (<80 bpm) only if symptoms persist despite lenient control. 1, 2
Patients with Reduced Ejection Fraction (LVEF ≤40%) or Heart Failure
Use only beta-blockers (bisoprolol, carvedilol, long-acting metoprolol) and/or digoxin; avoid diltiazem and verapamil because of negative inotropic effects. 1, 2, 3
If monotherapy fails, combine digoxin with a beta-blocker, monitoring closely for bradycardia. 1, 2
In severe left-ventricular dysfunction with hemodynamic instability, intravenous amiodarone (150 mg over 10 minutes, then 1 mg/min infusion) may be employed. 1, 3
Critical Pitfall
Digoxin alone is ineffective for rate control in paroxysmal atrial fibrillation, especially during exercise or sympathetic surge—it should never be used as monotherapy in this setting. 1, 2
Rhythm Control Indications
Consider rhythm control for:
- Patients who remain symptomatic despite adequate rate control 1, 2
- Younger patients (<65 years) with new-onset atrial fibrillation 2
- Patients with rate-related cardiomyopathy (newly detected heart failure with rapid ventricular response) 2
- Hemodynamically unstable patients 1, 2
Rhythm control does not reduce mortality compared to rate control and causes more hospitalizations and adverse drug effects—pursue it only for symptom relief or specific indications above. 1, 2
Cardioversion Protocol
Pre-Cardioversion Anticoagulation
For atrial fibrillation lasting ≥48 hours or of unknown duration:
- Provide therapeutic anticoagulation for at least 3 weeks before elective cardioversion 1, 2, 4
- OR perform transesophageal echocardiography to exclude left-atrial thrombus; if negative, proceed with cardioversion after initiating heparin 1, 2, 4
Continue anticoagulation for a minimum of 4 weeks after cardioversion regardless of rhythm outcome, due to risk of post-cardioversion atrial stunning. 1, 2
For atrial fibrillation <48 hours in duration, cardioversion may proceed after initiating anticoagulation, but patients with CHA₂DS₂-VASc ≥2 should receive anticoagulation even for short-duration episodes. 2
Cardioversion Methods
Electrical cardioversion is preferred for hemodynamically unstable patients or when rapid conversion is essential. 1, 2
Pharmacological cardioversion options:
- No structural heart disease: flecainide (200–300 mg oral or 1.5–2 mg/kg IV) or propafenone (450–600 mg oral or 1.5–2 mg/kg IV) 2
- Structural heart disease or reduced ejection fraction: amiodarone (5–7 mg/kg IV over 1–2 hours, then 50 mg/h infusion) 2
Antiarrhythmic Drug Selection (for Rhythm Maintenance)
Select antiarrhythmic drugs strictly based on cardiac structure and LVEF:
No Structural Heart Disease (normal LVEF, no coronary disease, no LV hypertrophy)
First-line: flecainide, propafenone, or sotalol. 1, 2
Coronary Artery Disease with LVEF >35%
Sotalol is preferred; requires hospitalization with continuous ECG monitoring for ≥3 days, with dose adjusted to renal function. 2
Heart Failure or LVEF ≤40%
Only amiodarone or dofetilide are safe options—other antiarrhythmics carry high pro-arrhythmic risk. 1, 2
Special Clinical Scenarios
Wolff-Parkinson-White Syndrome with Pre-Excited Atrial Fibrillation
If hemodynamically unstable, deliver immediate electrical cardioversion. 2, 3
If stable, give intravenous procainamide (≈15 mg/kg over 20–30 minutes) or ibutilide (1 mg over 10 minutes). 2, 3
NEVER use AV-nodal blocking agents (adenosine, beta-blockers, calcium-channel blockers, digoxin, intravenous amiodarone) because they can accelerate ventricular rate and precipitate ventricular fibrillation. 1, 2, 3
Postoperative Atrial Fibrillation
Give prophylactic oral beta-blocker postoperatively to reduce incidence of new-onset atrial fibrillation, unless contraindicated. 2
If postoperative atrial fibrillation occurs, achieve rate control with AV-node-blocking agents. 2
Chronic Obstructive Pulmonary Disease
Prefer non-dihydropyridine calcium-channel blockers (diltiazem or verapamil) and avoid beta-blockers. 1, 2, 3
Catheter Ablation
Catheter ablation is recommended as second-line therapy after failure of antiarrhythmic drugs, or as first-line in carefully selected patients with paroxysmal atrial fibrillation. 1, 2
Do not perform catheter ablation without a prior trial of medical therapy, except in selected patients with paroxysmal atrial fibrillation or heart failure with reduced ejection fraction. 2
Initial Diagnostic Workup
Obtain a 12-lead ECG to confirm atrial fibrillation (irregular rhythm, absent P waves) and assess ventricular rate. 2
Obtain transthoracic echocardiogram to evaluate left-atrial size, left-ventricular function, valvular disease, and structural abnormalities. 1, 2
Screen for reversible precipitants:
- Hyperthyroidism 2
- Acute alcohol intoxication 2
- Pulmonary embolism 2
- Myocardial infarction 2
- Pericarditis or myocarditis 2
- Hypertensive crisis 2
- Obstructive sleep apnea 2
Complete blood tests for thyroid, renal, and hepatic function to identify reversible causes. 2
Common Pitfalls to Avoid
Do not combine more than two AV-nodal blocking agents (beta-blocker, digoxin, amiodarone) due to risk of severe bradycardia or asystole. 2, 3
Do not use nondihydropyridine calcium-channel antagonists in decompensated heart failure as they may cause further hemodynamic compromise. 1
Do not discontinue anticoagulation solely because sinus rhythm has been restored—stroke risk is determined by CHA₂DS₂-VASc score, not rhythm status. 2
In patients with pre-excitation and atrial fibrillation, do not administer digoxin, nondihydropyridine calcium-channel antagonists, or intravenous amiodarone as they may increase ventricular response and result in ventricular fibrillation. 1