How to control tachycardia in an 87-year-old female with A fib, CKD stage 2, and normal blood pressure, currently on Metoprolol succinate (metoprolol) 75 mg and Eliquis (apixaban)?

Management of Rapid Atrial Fibrillation in an Elderly Patient with CKD Stage 2 and Normal Blood Pressure

For this 87-year-old female with atrial fibrillation and heart rate of 130-140 bpm, increase the metoprolol succinate dose to 100-200 mg daily while monitoring blood pressure, as this is the most effective strategy that will control heart rate without significantly reducing her already borderline blood pressure. 1

Current Medication Assessment

• Metoprolol succinate 75 mg daily (current dose insufficient for rate control)
• Apixaban (Eliquis) for anticoagulation (appropriate for CKD stage 2)

Recommended Rate Control Strategy

First-Line Approach:

1. Increase metoprolol succinate dose:
   • Current dose: 75 mg daily
   • Target dose: 100-200 mg daily 1, 2
   • Titration: Increase by 25-50 mg increments every 1-2 weeks
   • Monitor: Heart rate, blood pressure, and symptoms

Alternative Options (if metoprolol titration is ineffective or not tolerated):

1. Consider adding diltiazem:

   • Starting dose: 120 mg daily (extended release)
   • Target dose: 120-360 mg daily 1
   • Caution: Recent evidence shows increased bleeding risk when combined with apixaban 3

2. Consider adding digoxin:

   • Starting dose: 0.125 mg daily
   • Target dose: 0.125-0.25 mg daily 1, 2
   • Particularly useful in elderly patients with preserved blood pressure
   • Monitor: Serum levels, especially with CKD

3. Consider oral amiodarone (if other measures unsuccessful):

   • Starting dose: 100 mg daily
   • Target dose: 100-200 mg daily 1, 2
   • Class IIb recommendation when other measures fail 1
   • Requires careful monitoring for side effects

Rationale for Metoprolol Dose Increase

1. Efficacy in AF rate control:

   • Beta-blockers are first-line agents for rate control in AF 1, 2
   • Metoprolol has been shown to effectively maintain rate control during rest and exercise 4
   • The recommended dose range for metoprolol succinate is 50-400 mg daily 1

2. Blood pressure considerations:

   • At 75 mg, patient still has adequate BP (100/70 mmHg)
   • Metoprolol's effect on blood pressure is dose-dependent but generally less pronounced than with calcium channel blockers 5
   • Can be titrated slowly to minimize BP reduction

3. Safety in elderly and CKD:

   • Metoprolol is relatively safe in CKD stage 2 without dose adjustment 6
   • Already tolerated by the patient at current dose
   • Less risk of significant hypotension compared to calcium channel blockers 5

Heart Rate Targets

• Initial target: Resting heart rate <110 bpm 1, 2
• Optimal target: Resting heart rate <80 bpm if symptoms persist 1, 2
• During moderate exercise: Heart rate <110 bpm 2

Monitoring Recommendations

1. Short-term monitoring:

   • Check heart rate and blood pressure 1-2 weeks after dose adjustment
   • Assess for symptoms of bradycardia or hypotension
   • ECG to confirm adequate rate control

2. Long-term monitoring:

   • Regular assessment of heart rate during rest and with activity
   • Periodic 24-hour Holter monitoring to assess rate control throughout daily activities
   • Monitor renal function due to CKD stage 2

Important Considerations

• Avoid calcium channel blockers at high doses: Recent evidence shows diltiazem doses >120 mg/day increase bleeding risk when combined with apixaban (HR 1.29; 95% CI 1.19-1.39) 3

• Avoid abrupt discontinuation of beta-blockers as this may precipitate rebound tachycardia 1

• Age-related factors: Elderly patients may be more sensitive to beta-blockers; careful titration is essential 1

• CKD implications: Metoprolol does not require dose adjustment in CKD stage 2, making it preferable to other agents 6

• If rate control remains inadequate despite maximum tolerated doses of medications, consider AV nodal ablation with permanent pacemaker implantation 1, 2