How do I treat atrial fibrillation (afib) with rapid ventricular response (RVR) in a patient with hypotension?

From the Guidelines

For a patient with atrial fibrillation with rapid ventricular response (AFib with RVR) who is hypotensive, immediate cardioversion is the recommended first-line treatment. This approach is based on the most recent and highest quality evidence from the 2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation 1. The guideline recommends urgent cardioversion for patients with hemodynamic compromise, which includes hypotension.

Key Considerations

• Begin with synchronized electrical cardioversion at 120-200 joules using a biphasic defibrillator.
• If the patient is conscious, consider brief procedural sedation with medications like etomidate (0.1-0.2 mg/kg IV) or midazolam (1-2 mg IV) if time and resources permit.
• Avoid rate-controlling medications like beta-blockers, calcium channel blockers, or digoxin as these can worsen hypotension in this scenario.
• After successful cardioversion, address the underlying cause of the AFib (such as sepsis, hypovolemia, or electrolyte abnormalities) and consider starting anticoagulation if the patient has risk factors for thromboembolism.

Alternative Approaches

• If cardioversion fails or is temporarily unavailable, cautious use of low-dose vasopressors (norepinephrine 0.01-0.3 mcg/kg/min) may help support blood pressure while preparing for cardioversion.
• In patients with heart failure, a beta blocker or nondihydropyridine calcium channel antagonist may be recommended to slow ventricular response to AF in the acute setting, exercising caution in patients with overt congestion, hypotension, or HFrEF 1.

Prioritizing Hemodynamic Stability

The approach prioritizes hemodynamic stability first, as the rapid heart rate combined with hypotension indicates the patient is not tolerating the arrhythmia and requires immediate intervention to prevent further decompensation. This is in line with the recommendations from the 2014 AHA/ACC/HRS guideline, which emphasizes the importance of urgent cardioversion in patients with hemodynamic compromise 1.

From the FDA Drug Label

In the event of breakthrough episodes of VF or hemodynamically unstable VT, use 150 mg supplemental infusions of amiodarone (mixed in 100 mL of D5W and infused over 10 minutes to minimize the potential for hypotension) Treat hypotension initially by slowing the infusion; additional standard therapy may be needed, including the following: vasopressor drugs, positive inotropic agents, and volume expansion.

To treat atrial fibrillation (afib) with rapid ventricular response (RVR) in a patient with hypotension, amiodarone (IV) can be used with caution.

• The initial dose of amiodarone should be administered carefully to avoid exacerbating hypotension.
• If hypotension occurs, the infusion rate should be slowed, and additional standard therapy such as vasopressor drugs, positive inotropic agents, and volume expansion may be needed.
• It is essential to monitor the patient closely and adjust the treatment as necessary to balance the need to control the arrhythmia with the risk of worsening hypotension 2, 2.
• Diltiazem (IV) is contraindicated in patients with severe hypotension or cardiogenic shock, making it an unsuitable option for this patient 3.

From the Research

Treatment Options for Atrial Fibrillation with Rapid Ventricular Response (RVR) in Patients with Hypotension

• Intravenous (IV) diltiazem and metoprolol are commonly used to achieve rate control for atrial fibrillation with RVR (Afib with RVR) and are recommended as first-line treatments by current guidelines 4.
• A study comparing IV diltiazem and metoprolol for Afib with RVR found that metoprolol was associated with a 26% lower risk of adverse events (AEs) compared to diltiazem, although there was no difference in rates of hypotension or bradycardia 4.
• In patients with heart failure (HF), diltiazem is not recommended due to its negative inotropic effects, but studies have found similar safety and effectiveness outcomes between diltiazem and metoprolol in this population 5, 6, 7.

Considerations for Patients with Hypotension

• A study examining the hemodynamic effects of IV diltiazem and metoprolol found that both agents caused similar reductions in systolic blood pressure (SBP) and rates of clinically relevant hypotension 8.
• Another study found that IV diltiazem resulted in greater heart rate reductions at 30 minutes and 60 minutes compared to metoprolol, but with no difference in safety outcomes 5.
• In patients with heart failure with reduced ejection fraction (HFrEF), IV diltiazem achieved similar rate control with no increase in adverse events compared to IV metoprolol 6, 7.

Key Findings

• IV metoprolol and diltiazem are both effective for rate control in Afib with RVR, but metoprolol may have a lower risk of AEs 4.
• In patients with HF, diltiazem may not be contraindicated, but its use should be carefully considered due to potential negative inotropic effects 5, 6, 7.
• Both diltiazem and metoprolol can cause reductions in SBP, but the risk of clinically relevant hypotension is similar between the two agents 8.