What is the recommended treatment pathway for a patient with atrial fibrillation (AF) and rapid ventricular response (RVR)?

Management of Atrial Fibrillation with Rapid Ventricular Response

For hemodynamically stable patients with AF-RVR and preserved ejection fraction, administer intravenous diltiazem or metoprolol as first-line therapy, targeting heart rate <110 bpm; for patients with reduced ejection fraction or decompensated heart failure, use intravenous digoxin or amiodarone instead, as beta-blockers and calcium channel blockers are contraindicated in this setting. 1, 2, 3

Initial Assessment

Assess hemodynamic stability immediately upon presentation. 1, 2, 3

• Proceed directly to synchronized electrical cardioversion if the patient exhibits hypotension, pulmonary edema, ongoing myocardial ischemia, angina, or shock 1, 2
• Do not delay cardioversion for anticoagulation in hemodynamically unstable patients 1, 2

Obtain a 12-lead ECG to identify pre-excitation (delta waves suggesting Wolff-Parkinson-White syndrome) before administering any medications. 1, 2, 3

• If pre-excitation is present, never administer AV nodal blockers (beta-blockers, calcium channel blockers, digoxin, adenosine, or amiodarone) as they can accelerate ventricular rate and precipitate ventricular fibrillation 1, 2, 3
• For pre-excited AF with hemodynamic instability, perform immediate cardioversion 1, 2
• For hemodynamically stable pre-excited AF, administer intravenous procainamide or ibutilide 1, 3

Rate Control Strategy for Hemodynamically Stable Patients

Step 1: Determine Left Ventricular Function

Obtain or review echocardiogram to assess left ventricular ejection fraction (LVEF), as this dictates medication selection. 1, 2, 3

Step 2: Select Rate Control Agent Based on LVEF and Comorbidities

For LVEF >40% (Preserved Function)

Administer intravenous beta-blockers or non-dihydropyridine calcium channel blockers as first-line agents. 1, 2, 3

Beta-blocker options: 1, 2

• Metoprolol: 2.5–5 mg IV bolus over 2 minutes; may repeat up to 3 doses 1
• Esmolol: 500 mcg/kg IV bolus over 1 minute, then 50–300 mcg/kg/min infusion 1
• Propranolol: 1 mg IV over 1 minute, up to 3 doses at 2-minute intervals 1

Calcium channel blocker options: 1, 2

• Diltiazem: 0.25 mg/kg IV bolus over 2 minutes (lower doses of ≤0.2 mg/kg may reduce hypotension risk while maintaining efficacy), then 5–15 mg/h infusion 1, 4
• Verapamil: 0.075–0.15 mg/kg IV bolus over 2 minutes; may give additional 10 mg after 30 minutes if no response 1

Diltiazem likely achieves rate control faster than metoprolol, though both are safe and effective. 5

Target resting heart rate <110 bpm. 1, 2, 3

For LVEF ≤40% or Decompensated Heart Failure

Use intravenous digoxin or amiodarone; avoid beta-blockers and calcium channel blockers entirely. 1, 2, 3

• Digoxin is the preferred first-line agent for patients with volume overload or borderline blood pressure, as it does not cause hypotension or negative inotropy 3, 6
• Digoxin: 0.25 mg IV with repeat dosing to maximum of 1.5 mg over 24 hours 1
• Limitation: Digoxin controls only resting heart rate and is ineffective during exercise 1, 3, 6

Amiodarone is a reasonable alternative when digoxin is contraindicated or the patient is critically ill. 1, 3

• Amiodarone: 300 mg IV over 1 hour, then 10–50 mg/h over 24 hours 1

Non-dihydropyridine calcium channel blockers (diltiazem, verapamil) are absolutely contraindicated in decompensated heart failure as they worsen hemodynamics and can precipitate cardiogenic shock. 1, 2, 3

For COPD or Active Bronchospasm

Use diltiazem or verapamil; avoid beta-blockers. 2, 3

Step 3: Combination Therapy if Monotherapy Fails

Add digoxin to a beta-blocker or calcium channel blocker when single-agent therapy does not achieve adequate rate control at rest and during exercise. 1, 3

Oral amiodarone may be considered only when resting and exercise heart rate cannot be adequately controlled using other agents. 1, 3

Anticoagulation Management

Assess stroke risk using CHA₂DS₂-VASc score. 2, 3, 7, 8

For CHA₂DS₂-VASc score ≥2, initiate oral anticoagulation immediately. 2, 3

Direct oral anticoagulants (DOACs) are preferred over warfarin due to lower intracranial hemorrhage risk. 2, 7, 8

• Apixaban 5 mg twice daily (or 2.5 mg twice daily if ≥2 of: age ≥80, weight ≤60 kg, creatinine ≥1.5 mg/dL) 2

If warfarin is used, target INR 2.0–3.0 with weekly monitoring during initiation, then monthly when stable. 1, 2

Cardioversion Considerations

If AF duration >48 hours or unknown, require 3 weeks of therapeutic anticoagulation before elective cardioversion. 1, 2, 3

Alternative approach: Perform transesophageal echocardiography (TEE) to exclude left atrial thrombus, allowing earlier cardioversion if negative. 1, 2

If AF duration <48 hours, may proceed with cardioversion after initiating anticoagulation. 1, 2

Continue anticoagulation for minimum 4 weeks after cardioversion in all patients. 1, 2, 3

Long-term anticoagulation should be based on CHA₂DS₂-VASc score regardless of whether sinus rhythm is maintained. 1, 2, 3

Disposition and Follow-Up

Hospitalization is required for: 2, 3

• Initial rate control requiring IV medications
• Cardioversion performed
• Suspected tachycardia-induced cardiomyopathy
• Initiation of antiarrhythmic drugs requiring monitoring

Discharge criteria: 2, 3

• Adequate rate control achieved (<110 bpm at rest)
• Hemodynamically stable
• Anticoagulation initiated
• Adequate medication supply provided

Ensure follow-up arranged for INR monitoring if on warfarin. 2, 3

Monitor renal function at least annually for DOAC patients. 2

Critical Pitfalls to Avoid

Never use calcium channel blockers in decompensated heart failure or LVEF ≤40%, as they can precipitate cardiogenic shock. 1, 2, 3

Never use AV nodal blockers (diltiazem, verapamil, beta-blockers, digoxin, adenosine, amiodarone) in Wolff-Parkinson-White syndrome with pre-excitation, as they accelerate ventricular rate and can precipitate ventricular fibrillation. 1, 2, 3

Never cardiovert without 3 weeks of anticoagulation or TEE when AF duration >48 hours or unknown. 1, 2, 3

Never discontinue anticoagulation after successful cardioversion if stroke risk factors persist (CHA₂DS₂-VASc ≥2). 1, 2, 3

Never use digoxin as the sole agent for rate control in active patients or those with paroxysmal AF, as it only controls resting heart rate. 1, 3

AV nodal ablation should not be performed without prior attempts to achieve rate control with medications. 1, 3