What is the treatment for hemodynamically stable Atrial Fibrillation (A-fib) with Rapid Ventricular Response (RVR)?

Treatment of Hemodynamically Stable Atrial Fibrillation with Rapid Ventricular Response

For hemodynamically stable atrial fibrillation with rapid ventricular response (AF with RVR), the first-line treatment is intravenous beta-blockers or nondihydropyridine calcium channel blockers, with medication choice based on the patient's left ventricular ejection fraction. 1, 2

Initial Assessment

• Confirm hemodynamic stability (absence of hypotension, acute heart failure, or altered mental status)
• Determine left ventricular ejection fraction (LVEF) status, as this guides medication selection
• Identify any underlying causes (thyrotoxicosis, pulmonary disease, etc.)

Treatment Algorithm Based on LVEF

For patients with preserved LVEF (>40%):

1. First-line options (either):

   • IV beta-blocker (e.g., metoprolol 2.5-5 mg IV bolus over 2 min)
   • IV nondihydropyridine calcium channel blocker (e.g., diltiazem 0.25 mg/kg IV over 2 min, then 5-15 mg/h IV)

2. If first agent fails to achieve rate control:

   • Consider adding the other class (beta-blocker + calcium channel blocker)
   • This combination achieves rate control in approximately 46% of patients who fail monotherapy 3

For patients with reduced LVEF (≤40%):

1. First-line options:

   • IV beta-blocker (use with caution in patients with overt congestion)
   • IV digoxin (0.25 mg IV every 2 hours, up to 1.5 mg)
   • IV amiodarone (150 mg IV over 10 min, then 0.5-1 mg/min IV)

2. Avoid nondihydropyridine calcium channel blockers in patients with reduced LVEF due to negative inotropic effects 2

Special Considerations

For patients with specific comorbidities:

• COPD/Pulmonary disease: Nondihydropyridine calcium channel antagonists are recommended 1
• Thyrotoxicosis: Beta-blockers are first-line; if contraindicated, use nondihydropyridine calcium channel antagonists 1
• Wolff-Parkinson-White syndrome: Avoid digoxin, adenosine, and calcium channel blockers; use procainamide or ibutilide 1

Rate Control Targets:

• Initial lenient rate control with resting heart rate <110 bpm is acceptable 2
• Consider stricter targets if symptoms persist or tachycardia-induced cardiomyopathy is suspected 2

Second-line Options

• If pharmacological therapy fails to control heart rate:

  • Consider AV node ablation with ventricular pacing 1, 2
  • This is particularly useful in severely symptomatic patients with permanent AF 2

• For patients who remain symptomatic despite rate control:

  • Consider rhythm control strategy (cardioversion or antiarrhythmic medications) 1

Important Caveats

• Digoxin alone is not effective for rapid rate control in acute AF with RVR but may be useful in combination with other agents 2
• Recent evidence suggests diltiazem may achieve rate control faster than metoprolol, though both are effective 4
• While traditionally contraindicated, limited evidence suggests diltiazem might be considered as a second-line option in HFrEF patients when beta-blockers fail, though more research is needed 5
• Always provide appropriate anticoagulation based on CHA₂DS₂-VASc score alongside rate control 2, 6

Remember that if the patient becomes hemodynamically unstable at any point, immediate synchronized cardioversion is indicated 1, 2, 7.