Can diltiazem be given for atrial fibrillation (AFib) with rapid ventricular response (RVR) and a baseline left ventricular ejection fraction (LVEF) of 35%?

Management of Atrial Fibrillation with Rapid Ventricular Response in a Patient with LVEF 35%

Diltiazem should not be used for atrial fibrillation with rapid ventricular response in a patient with an ejection fraction of 35% due to its negative inotropic effects that may worsen heart failure. 1

First-Line Treatment Options for AFib RVR with LVEF 35%

• Beta-blockers are the recommended first-line agents for rate control in patients with atrial fibrillation and reduced ejection fraction (LVEF <40%) 1
• The smallest effective dose of beta-blocker should be used to achieve rate control in patients with heart failure 1
• Amiodarone is an alternative option for patients with hemodynamic instability or severely reduced LVEF who cannot tolerate beta-blockers 1

Why Diltiazem Should Be Avoided

• Non-dihydropyridine calcium channel blockers (diltiazem, verapamil) should be avoided in patients with reduced left ventricular function (LVEF ≤40%) due to their negative inotropic effects 1
• The European Society of Cardiology explicitly recommends against diltiazem in patients with LVEF <40% as it may worsen heart failure 1
• Diltiazem causes excitation-contraction uncoupling in myocardial tissues and has a negative inotropic effect in isolated preparations 2

Treatment Algorithm for AFib RVR with LVEF 35%

1. Initial therapy: Start with the smallest dose of beta-blocker to achieve rate control 1

   • Options include metoprolol, esmolol, or propranolol at appropriate doses 1
   • Initial resting heart rate target should be <110 bpm 1

2. If beta-blockers are ineffective or contraindicated:

   • Add digoxin as a second-line agent 1
   • Consider amiodarone for patients with hemodynamic instability 1

3. Monitoring:

   • Perform echocardiogram to determine further management and choice of maintenance therapy 1
   • Avoid bradycardia 1
   • Consider need for anticoagulation based on CHA₂DS₂-VA score 1

Recent Research Considerations

• Despite traditional recommendations against diltiazem in reduced EF, some recent small studies suggest comparable safety and effectiveness between metoprolol and diltiazem in the acute management of AFib with RVR in HFrEF patients 3, 4
• However, these studies have significant limitations including small sample sizes and retrospective design 3, 4, 5
• A 2024 observational study found that patients with reduced EF who received diltiazem had a higher incidence of worsening heart failure (17%) compared to those with preserved EF (4.8%) 6

Practical Considerations

• When using beta-blockers, start with low doses and titrate carefully to avoid hypotension and bradycardia 7
• For long-term management, consider the four cornerstone medications for heart failure with reduced EF (beta-blockers, ACE inhibitors/ARBs, mineralocorticoid receptor antagonists, and SGLT2 inhibitors) 8
• Regular reassessment of LVEF is recommended to guide therapy adjustments 8

Common Pitfalls to Avoid

• Using diltiazem in patients with LVEF <40% despite its effectiveness in rate control due to potential worsening of heart failure 1
• Discontinuing heart failure medications inappropriately, which increases risk of relapse of heart failure and LV dysfunction 8
• Failing to consider the need for anticoagulation based on stroke risk factors 1