What is the best course of action for a 64-year-old male with a history of atrial fibrillation, currently on Flecainide (flecainide), Metoprolol (metoprolol), and Eliquis (apixaban), presenting with tachycardia and an irregularly irregular rhythm?

Urgent Cardiology Evaluation Required Within 1-2 Weeks

This patient requires urgent cardiology follow-up within 1-2 weeks, not several weeks, due to breakthrough atrial fibrillation with rapid ventricular response despite triple antiarrhythmic therapy. 1, 2

Immediate Clinical Concerns

This presentation represents treatment failure of his current rhythm and rate control regimen:

• The patient is experiencing breakthrough AFib with RVR (115 bpm irregularly irregular) despite being on flecainide (rhythm control), metoprolol (rate control), and therapeutic anticoagulation 1, 2
• The American College of Cardiology emphasizes that patients with symptoms suggesting hypoperfusion or rate-related cardiac ischemia require immediate evaluation 1
• An irregularly irregular rhythm at 115 bpm confirms atrial fibrillation with inadequate rate control, as the target heart rate should be 80-110 bpm at rest 1, 2

Why This Cannot Wait Several Weeks

Hemodynamic assessment is critical - you must evaluate for:

• Symptoms of dizziness, visual changes, chest discomfort, or dyspnea that may indicate hypoperfusion, transient ischemic attack, stroke, or rate-related cardiac ischemia 1
• Signs of heart failure exacerbation, as flecainide has negative inotropic effects and can worsen CHF, particularly concerning given his inadequate rate control 3
• The European Heart Journal recommends discharge only if rate control is achieved, neurological symptoms are resolved, and close cardiology follow-up is arranged within 1-2 weeks 1

Immediate Management Steps in Clinic

Rate Control Optimization

Increase his metoprolol dose immediately:

• The American College of Cardiology recommends increasing the home beta-blocker dose for patients experiencing breakthrough rapid ventricular response 1
• Consider uptitrating metoprolol to 25-100 mg twice daily for chronic rate control 2
• If he is hemodynamically stable but symptomatic, IV metoprolol 2.5-5 mg over 2 minutes can be administered for immediate rate control 1, 2

Consider adding digoxin as second-line agent:

• The American College of Cardiology recommends adding digoxin (Class I, Level B recommendation) to a beta blocker for inadequate response, as the combination produces synergistic effects on the AV node 2
• Beta-blockers are effective for rate control both at rest and during exercise, while digoxin is only effective at rest 4, 2

Critical Safety Warning

Never combine more than two of the following three drugs: beta blocker, digoxin, and amiodarone due to risk of severe bradycardia, third-degree AV block, and asystole 2

Cardiology Consultation Priorities

The cardiologist needs to address within 1-2 weeks:

• Flecainide efficacy assessment - His current flecainide dose may be inadequate, as doses can be increased in increments of 50 mg twice daily every four days until efficacy is achieved, with maximum dose of 300 mg/day for paroxysmal AFib 3
• Rhythm control strategy reconsideration - The combination of flecainide and metoprolol significantly reduces AFib recurrences compared to flecainide alone (66.7% vs 46.8% at 1 year) 5
• Cardioversion consideration - If AFib duration is >48 hours, cardioversion should not be attempted without either 3 weeks of therapeutic anticoagulation or transesophageal echocardiography to exclude left atrial thrombus 4, 1

Documentation Requirements

Obtain 12-lead ECG in clinic to:

• Confirm atrial fibrillation with rapid ventricular response 1
• Assess QRS duration, as flecainide increases QRS by approximately 25% and caution is needed if QRS exceeds 0.18 seconds 3
• Evaluate for ischemic changes 1

Anticoagulation Verification

• Confirm he is adherent to apixaban, as his CHA₂DS₂-VASc score (age 64 = 1 point, male = 0 points, plus any additional risk factors) determines stroke risk 1
• Patients with multiple stroke risk factors require continued anticoagulation indefinitely 1

Common Pitfalls to Avoid

• Do not delay cardiology referral to several weeks - breakthrough AFib on triple therapy requires urgent reassessment 1
• Do not add amiodarone without cardiology consultation - it should only be considered when both beta blockers and digoxin are contraindicated or ineffective 2
• Do not attempt cardioversion in clinic if AFib duration is unknown or >48 hours without proper anticoagulation protocol 4, 1
• Do not ignore potential heart failure symptoms - flecainide can cause or worsen CHF, and new or worsened CHF developed in 6.3% of patients with ventricular arrhythmias 3