Management of Atrial Fibrillation
Atrial fibrillation management centers on three simultaneous pillars: anticoagulation for stroke prevention, rate control for symptom management, and rhythm control in selected patients—all guided by hemodynamic stability and stroke risk stratification. 1
Immediate Assessment: Hemodynamic Stability
Perform immediate synchronized electrical cardioversion (120–200 J biphasic) without waiting for anticoagulation in any patient with hypotension, acute heart failure, ongoing chest pain, altered mental status, shock, or pulmonary edema. 2, 3 Concurrent intravenous heparin bolus may be given if feasible. 3
In hemodynamically stable patients, confirm AF with a 12-lead ECG documenting irregular rhythm and absent P waves. 2, 3
Identify and treat reversible precipitants: thyroid dysfunction, electrolyte abnormalities (especially hypokalemia), acute alcohol intoxication, pulmonary embolism, myocardial infarction, pericarditis, myocarditis, hypertensive crisis, obstructive sleep apnea, and sepsis. 2, 3, 4
Stroke Risk Assessment and Anticoagulation
Calculate CHA₂DS₂-VASc Score Immediately
- Congestive heart failure (1 point), Hypertension (1 point), Age ≥75 years (2 points), Diabetes (1 point), prior Stroke/TIA/thromboembolism (2 points), Vascular disease (1 point), Age 65–74 years (1 point), Sex category female (1 point). 2, 4
Anticoagulation Thresholds
Initiate oral anticoagulation for all patients with CHA₂DS₂-VASc ≥2 (men) or ≥3 (women). 2, 4 This is a Class I recommendation. 2
Consider anticoagulation for CHA₂DS₂-VASc = 1 (men) or = 2 (women) after individualized assessment of bleeding risk and patient preference. 2
No anticoagulation is needed for CHA₂DS₂-VASc = 0. 4
Choice of Anticoagulant
Prescribe direct oral anticoagulants (apixaban, rivaroxaban, edoxaban, or dabigatran) as first-line therapy over warfarin in all patients except those with mechanical heart valves or moderate-to-severe mitral stenosis. 2, 4, 5 DOACs reduce intracranial hemorrhage risk by 60–80% compared with placebo and have more predictable pharmacokinetics than warfarin. 2, 5
If warfarin is used, target INR 2.0–3.0 with weekly monitoring during initiation and monthly monitoring once stable. 2, 3, 6 For patients with prosthetic heart valves, the target INR may be increased to 2.5–3.5 depending on valve type and position. 6
Aspirin alone or aspirin plus clopidogrel are not recommended for stroke prevention in AF; they provide inferior efficacy compared with anticoagulation and do not have a significantly better safety profile. 4, 5
Rate Control Strategy
First-Line Agents by Left Ventricular Ejection Fraction
For patients with preserved LVEF >40%: use intravenous β-blockers (metoprolol 2.5–5 mg IV bolus over 2 minutes, repeat up to three doses) or non-dihydropyridine calcium-channel blockers (diltiazem 0.25 mg/kg IV bolus over 2 minutes, followed by continuous infusion 5–15 mg/h). 2, 3, 4 Oral dosing: atenolol 25–100 mg once daily, metoprolol, diltiazem 60–120 mg three times daily (120–360 mg extended release), or verapamil 40–120 mg three times daily (120–480 mg extended release). 2
For patients with reduced LVEF ≤40% or heart failure: limit therapy to β-blockers (bisoprolol, carvedilol, long-acting metoprolol) and/or digoxin (0.25 mg IV, repeat doses up to cumulative maximum 1.5 mg within 24 hours; oral 0.0625–0.25 mg per day). 2, 3, 4 Avoid diltiazem and verapamil because of negative inotropic effects. 2, 3, 4
Rate Control Targets
- Target a lenient resting heart rate <110 bpm initially; pursue stricter control <80 bpm only if symptoms persist despite lenient control. 2, 4 The RACE II trial demonstrated lenient rate control was non-inferior to strict control for clinical outcomes. 2
Combination Therapy
If monotherapy fails, combine digoxin with a β-blocker or a calcium-channel blocker to improve control at rest and during exercise, monitoring closely for bradycardia. 2, 3, 4
Critical pitfall: Digoxin alone is ineffective for rate control in paroxysmal AF, especially during exercise or sympathetic surge. 2, 4 Do not use digoxin as sole agent in active patients. 4
Special Populations
In chronic obstructive pulmonary disease or active bronchospasm, preferentially use non-dihydropyridine calcium-channel blockers (diltiazem or verapamil) and avoid β-blockers. 2, 3
In thyrotoxicosis, administer a β-blocker to control ventricular response unless contraindicated. 2
In Wolff-Parkinson-White syndrome with pre-excited AF: If hemodynamically unstable, deliver immediate electrical cardioversion. If stable, give intravenous procainamide or ibutilide. Avoid AV-nodal blocking agents (adenosine, β-blockers, calcium-channel blockers, digoxin, amiodarone) because they may accelerate ventricular rate and precipitate ventricular fibrillation. 2, 3 Catheter ablation of the accessory pathway provides definitive treatment. 2
Rhythm Control Indications
Consider rhythm-control interventions (antiarrhythmic drugs or catheter ablation) for patients who remain symptomatic despite adequate rate control, are younger than 65 years with new-onset AF, have rate-related cardiomyopathy (newly detected heart failure with rapid ventricular response), or are hemodynamically unstable. 2, 4, 5
Rhythm control is not indicated for mortality reduction; the AFFIRM and RACE trials showed no survival advantage and higher rates of hospitalization and drug-related adverse events in the rhythm-control arm. 2, 4 Rate control with anticoagulation is equally effective as rhythm control for reducing mortality and cardiovascular events while causing fewer adverse effects. 2, 4
Cardioversion and Anticoagulation
Pre-Cardioversion Anticoagulation
For AF lasting >48 hours (or unknown duration), provide therapeutic anticoagulation for at least 3 weeks before elective cardioversion and continue for a minimum of 4 weeks after the procedure. 1, 2, 3, 4 This applies to both electrical and pharmacological cardioversion. 1
Alternatively, perform transesophageal echocardiography (TEE) to exclude left-atrial thrombus; if negative, proceed with cardioversion after initiating heparin, and continue anticoagulation for at least 4 weeks. 1, 2, 3 If thrombus is identified on TEE, warfarin (INR 2.0–3.0) is recommended for at least 3 weeks, followed by repeat TEE to ensure thrombus resolution. 1
For AF duration <48 hours with CHA₂DS₂-VASc score ≥2, anticoagulation before cardioversion is recommended, as left atrial thrombus has been detected on TEE in up to 14% of patients with AF of short duration. 2 Finnish observational data showed stroke rates of 1.1% in patients with CHA₂DS₂-VASc ≥2 versus 0.2% with anticoagulation. 2
Post-cardioversion anticoagulation for at least 4 weeks is mandatory regardless of method, due to risk of thrombo-embolism from post-cardioversion left atrial/LAA dysfunction ("atrial stunning"). 1, 2, 4
In patients with risk factors for stroke or AF recurrence, anticoagulation should be continued lifelong irrespective of apparent maintenance of sinus rhythm following cardioversion. 1, 2 In the AFFIRM trial, 72% of patients who suffered ischemic stroke had either discontinued anticoagulation or had an INR <2.0. 2
Antiarrhythmic Drug Selection (Based on Cardiac Structure & LVEF)
No Structural Heart Disease (Normal LVEF, No Coronary Disease, No LV Hypertrophy)
First-line agents: flecainide (200–300 mg oral or 1.5–2 mg/kg IV over 10 min), propafenone (450–600 mg oral or 1.5–2 mg/kg IV over 10 min), or sotalol. 2, 4 These drugs must be avoided in patients with coronary artery disease or significant structural heart disease. 2
"Pill-in-the-pocket" strategy: In selected individuals with infrequent symptomatic paroxysmal AF, a single oral dose of flecainide (200–300 mg) or propafenone (450–600 mg) can be self-administered at home, provided safety has first been confirmed in a supervised hospital setting. 2
Coronary Artery Disease with LVEF >35%
- Sotalol is preferred; requires hospitalization with continuous ECG monitoring for ≥3 days, dose adjusted to renal function. 2, 7 The baseline QT interval must be ≤450 msec to start sotalol. During initiation and titration, the QT interval should be monitored 2–4 hours after each dose. If the QT interval prolongs to ≥500 msec, the dose must be reduced or the drug discontinued. 7
Heart Failure or LVEF ≤40%
Amiodarone (5–7 mg/kg IV over 1–2 h followed by infusion of 50 mg/h, max 1 g/24 h; or 300 mg IV diluted in 250 ml of 5% glucose over 30–60 minutes) or dofetilide are the only safe options because other agents carry a high pro-arrhythmic risk. 2, 4 Conversion to sinus rhythm with amiodarone may be delayed (8–12 h). 2
Amiodarone is not appropriate as initial therapy in healthy patients without structural heart disease, as it carries significant organ toxicity risks and should be reserved for refractory cases or patients with contraindications to other agents. 4
Catheter Ablation
Catheter ablation is recommended as second-line therapy after failure of antiarrhythmic drugs in persistent AF, or as first-line therapy in carefully selected patients with symptomatic paroxysmal AF to improve symptoms and slow progression to persistent AF. 2, 4, 5
Catheter ablation is also recommended for patients with AF who have heart failure with reduced ejection fraction (HFrEF) to improve quality of life, left ventricular systolic function, and cardiovascular outcomes, such as rates of mortality and heart failure hospitalization. 5
Do not perform catheter ablation without a prior trial of medical therapy, except in selected patients with paroxysmal AF or heart failure with reduced ejection fraction. 2
Management of Permanent Atrial Fibrillation
When patient and physician agree that no further rhythm-restoration attempts will be made, focus exclusively on rate control and anticoagulation; rhythm-control interventions are omitted. 2
If maximal pharmacologic rate control fails, consider atrioventricular (AV) node ablation with pacemaker implantation. 2, 4 In severely symptomatic permanent AF patients with heart-failure hospitalization, AV node ablation combined with cardiac resynchronization therapy is reasonable. 2, 4
Comorbidity & Risk-Factor Management
- Aggressively manage modifiable risk factors to prevent AF recurrence and progression: 2
- Hypertension: aim for blood pressure <140/90 mmHg (stricter if tolerated). 2
- Obesity: achieve ≥10% body-weight loss to reduce AF burden. 2
- Obstructive sleep apnea: prescribe continuous positive airway pressure (CPAP) therapy. 2
- Diabetes: optimize glycemic control; consider metformin or SGLT2 inhibitors, as these agents may lower the incidence of AF. 2
- Alcohol: reduce or eliminate intake. 2
- Physical activity: encourage regular moderate-intensity exercise. 2
Clinical Follow-Up
At follow-up visits, record a 12-lead ECG to document rhythm and rate, and investigate disease progression. 1 For those on antiarrhythmic drug therapy, assess potential proarrhythmic ECG precursors such as lengthening of PR, QRS, or QT intervals, non-sustained ventricular tachycardia, or pauses. 1
Reassess stroke risk using the updated CHA₂DS₂-VASc score at 6 months after presentation, and then at least annually. 4 Has the risk profile changed (e.g., new diabetes or hypertension), especially with regard to the indication for anticoagulation? 1
Renal function should be evaluated at least annually when using DOACs, and more frequently if clinically indicated. 2
Common Pitfalls to Avoid
Never discontinue anticoagulation solely because sinus rhythm has been achieved; stroke risk is determined by the CHA₂DS₂-VASc score, not by rhythm status. 2 In the AFFIRM trial, 75% of thromboembolic events in the rhythm-control group occurred in patients who were believed to be in sinus rhythm. 2
Do not combine β-blockers with diltiazem or verapamil except under specialist supervision with ambulatory ECG monitoring for bradycardia. 2
Failing to identify and treat reversible causes of AF, such as thyroid dysfunction or electrolyte abnormalities. 3
Attempting cardioversion without appropriate anticoagulation in patients with AF lasting more than 48 hours. 3
Underdosing anticoagulation or inappropriate discontinuation increases stroke risk. 2
Using digoxin as the sole agent for rate control in paroxysmal AF is ineffective. 2