What is the best course of action for a patient with atrial fibrillation (AFib) and congestive heart failure (CHF) on metoprolol (Lopressor) 50mg, Entresto (sacubitril/valsartan), Xarelto (rivaroxaban), and Jardiance (empagliflozin) who is experiencing an irregular heartbeat?

Management of Irregular Heartbeat in AFib/CHF Patient on Optimal Medical Therapy

First, assess whether the patient is experiencing symptomatic rapid ventricular response (RVR) or simply perceiving their baseline irregular rhythm—this distinction determines whether rate control optimization versus reassurance is needed. 1

Initial Assessment

Immediately check the following critical parameters:

• Heart rate at rest and during activity - Target is <100 bpm at rest and <110 bpm during moderate exercise 1
• Blood pressure and signs of hemodynamic instability (hypotension, acute pulmonary edema, chest pain) 1
• Volume status - Look for signs of decompensated heart failure (peripheral edema, elevated JVP, pulmonary congestion) 1
• Medication adherence - Confirm the patient is actually taking metoprolol 50mg as prescribed 1

If Heart Rate is Adequately Controlled (<100 bpm at rest)

The irregular heartbeat sensation alone does not require intervention if rate control is adequate. 1

• Reassure the patient that irregular rhythm is expected with AFib and does not indicate treatment failure 1
• Confirm anticoagulation is therapeutic - Xarelto (rivaroxaban) provides appropriate stroke prevention for AFib with CHF 2
• Verify no new precipitating factors such as infection, thyroid dysfunction, electrolyte abnormalities, or medication non-adherence 1

If Heart Rate is Inadequately Controlled (≥100 bpm at rest or symptomatic RVR)

For Hemodynamically Stable Patients with HFrEF:

Optimize beta-blocker dosing first, as metoprolol 50mg may be subtherapeutic. 1, 3

• Increase metoprolol dose - Can titrate up to 200mg daily in divided doses for rate control in AFib 1
• Add digoxin if beta-blocker alone is insufficient - Combination therapy is reasonable for rate control in HF patients 1
• Consider amiodarone if rate remains uncontrolled despite beta-blocker and digoxin combination 1

Critical Medication Considerations:

Avoid non-dihydropyridine calcium channel blockers (diltiazem/verapamil) if the patient has reduced ejection fraction (HFrEF), as these are contraindicated due to negative inotropic effects. 1, 4 However, recent evidence suggests diltiazem may be safer than previously thought even in HF patients, though beta-blockers remain first-line 5.

Do NOT use digoxin as monotherapy - It is ineffective for acute rate control and works primarily at rest, not during activity 1, 3

For Hemodynamically Unstable Patients:

Proceed immediately to electrical cardioversion if the patient has symptomatic hypotension, acute pulmonary edema, ongoing chest pain, or signs of shock. 1

Role of Current Medications

The patient's Entresto (sacubitril/valsartan) may actually help maintain sinus rhythm if cardioversion is considered. 6, 7, 8

• Sacubitril/valsartan reduces atrial remodeling and improves success rates of cardioversion compared to valsartan alone 7, 8
• This provides an "upstream therapy" benefit for AFib beyond standard rate control 6

Jardiance (empagliflozin) and Xarelto do not directly affect rate control but are appropriate for the patient's CHF and stroke prevention respectively 2

When to Consider Rhythm Control Strategy

If the patient remains symptomatic despite adequate rate control, consider rhythm control with cardioversion and antiarrhythmic therapy. 1

• Amiodarone is the preferred antiarrhythmic for patients with heart failure and reduced ejection fraction 1
• Dofetilide is an alternative with proven safety in HF patients 1
• Avoid Class IC agents (flecainide, propafenone) in patients with structural heart disease 1

Common Pitfalls to Avoid

• Do not stop anticoagulation - Xarelto must be continued regardless of rate or rhythm control strategy, as stopping increases stroke risk 2
• Do not assume metoprolol 50mg is adequate - This is often a subtherapeutic dose for AFib rate control 1
• Do not use calcium channel blockers as first-line if HFrEF is present 1, 4
• Do not pursue AV node ablation without first attempting pharmacological rate control optimization 1

Specific Action Plan

Contact cardiology to:

1. Verify ejection fraction - Management differs significantly between HFrEF and HFpEF 1
2. Uptitrate metoprolol to 100-200mg daily if tolerated 1
3. Add digoxin 0.125-0.25mg daily if beta-blocker uptitration insufficient 1
4. Consider 24-hour Holter monitoring to assess rate control during activity 1