What is the best approach for a patient with atrial fibrillation (AF) and tachycardia, who recently stopped beta blockers (BB) due to bradycardia, and now presents with chest pain?

Management of Chest Pain with Atrial Fibrillation After Beta-Blocker Discontinuation

For a patient with atrial fibrillation presenting with chest pain and tachycardia (HR 110) after recent beta-blocker discontinuation due to bradycardia, the most appropriate approach is to restart a beta-blocker at a lower dose with careful titration to achieve rate control without causing bradycardia. 1

Initial Assessment and Stabilization

• Assess hemodynamic stability immediately:

  • If unstable (hypotension, altered mental status, shock): Immediate electrical cardioversion 1
  • If stable: Proceed with pharmacological rate control

• Evaluate chest pain:

  • Obtain 12-lead ECG to assess for ischemia
  • Consider cardiac enzymes to rule out acute coronary syndrome
  • Assess for other causes of chest pain (pulmonary embolism, aortic dissection)

Rate Control Strategy

First-line options (LVEF >40%):

• Beta-blockers: Preferred first-line therapy 1

  • Metoprolol: Start with 2.5-5 mg IV bolus over 2 min (up to 3 doses) or 25 mg orally twice daily 1, 2
  • Esmolol: 500 μg/kg IV over 1 min, then 50-300 μg/kg/min IV (useful for short-term control) 1, 2
  • Consider lower initial doses given previous bradycardia

• Non-dihydropyridine calcium channel blockers (if beta-blockers contraindicated): 1

  • Diltiazem: 0.25 mg/kg IV over 2 min, then 5-15 mg/h, or 40-120 mg orally three times daily 2
  • Verapamil: 0.075-0.15 mg/kg IV over 2 min, or 40-120 mg orally three times daily 2
  • Caution: Avoid in heart failure with reduced ejection fraction 1, 2

For patients with LVEF ≤40%:

• Beta-blockers: First choice (start at lower dose) 1
• Digoxin: Alternative or add-on therapy 1
  • 0.25 mg IV every 2 hours (up to 1.5 mg) or 0.125-0.25 mg orally daily 2
  • More effective when combined with beta-blockers 2

Rate Control Targets

• Initial target: Resting heart rate <110 bpm (lenient control) 1
• Consider stricter control (<80 bpm) if symptoms persist 1
• Monitor response during both rest and activity 1

Special Considerations

• Previous bradycardia: Start with lower doses of rate-controlling medications and titrate carefully
• Combination therapy: If single-agent therapy is insufficient, consider combination of beta-blocker with digoxin 1
• Amiodarone: Consider if other agents fail or are contraindicated (Class IIb recommendation) 1

Advanced Options for Refractory Cases

• If pharmacological therapy fails despite optimization:
  • Consider AV nodal ablation with permanent pacemaker implantation 1
  • For severely symptomatic patients with heart failure: AV node ablation with cardiac resynchronization therapy 1

Anticoagulation Assessment

• Calculate CHA₂DS₂-VASc score to assess stroke risk
• Initiate anticoagulation if score ≥2 in men or ≥3 in women 1, 2
• Choose direct oral anticoagulant (DOAC) over warfarin unless contraindicated 2

Pitfalls and Caveats

• Avoid non-dihydropyridine calcium channel blockers in patients with heart failure with reduced ejection fraction 1, 2
• Avoid digoxin as sole agent for rate control in paroxysmal AF 1
• Never use AV nodal blockers (beta-blockers, calcium channel blockers, digoxin) if pre-excitation syndrome (WPW) is suspected 1, 3
• Monitor for bradycardia when restarting beta-blockers, especially at night
• Combination of beta-blockers with calcium channel blockers should be used cautiously and only under specialist supervision 1

The most recent guidelines emphasize that rate control is the cornerstone of AF management when rhythm control is not pursued, with beta-blockers being the preferred first-line therapy in most clinical scenarios 1.