What is the treatment for emergent atrial fibrillation (afib) with rapid ventricular response (RVR)?

From the Guidelines

To treat emergent atrial fibrillation with rapid ventricular response (AFib with RVR), first stabilize the patient and control the heart rate with rate-controlling medications, such as beta-blockers, diltiazem, or verapamil, as recommended by the 2024 ESC guidelines 1. For hemodynamically unstable patients (hypotensive, altered mental status, chest pain, or heart failure), perform immediate synchronized cardioversion starting at 120-200 joules. For stable patients, administer rate-controlling medications:

• IV diltiazem (0.25 mg/kg over 2 minutes, followed by 5-15 mg/hour infusion)
• IV metoprolol (5 mg IV bolus over 2-5 minutes, may repeat twice)
• IV esmolol (500 mcg/kg loading dose over 1 minute, then 50-300 mcg/kg/min). Avoid beta-blockers in patients with heart failure or bronchospasm. Consider IV amiodarone (150 mg over 10 minutes, then 1 mg/min for 6 hours) for patients with heart failure or when other agents fail, as suggested by the 2014 AHA/ACC/HRS guideline 1. Correct electrolyte abnormalities, particularly potassium and magnesium. Provide supplemental oxygen if hypoxic and address any underlying triggers such as infection, thyrotoxicosis, or pulmonary embolism. After rate control is achieved, assess stroke risk to determine the need for anticoagulation, as recommended by the 2006 ACC/AHA/ESC guidelines 1. Rate control is essential because prolonged rapid heart rates can lead to tachycardia-induced cardiomyopathy and heart failure. The choice of rate-controlling medication should be based on the patient's underlying condition, such as heart failure or left ventricular dysfunction, and the potential side effects of the medication. In patients with heart failure, beta-blockers are the preferred agents for achieving rate control, unless otherwise contraindicated, as stated in the 2014 AHA/ACC/HRS guideline 1. Digoxin may be an effective adjunct to a beta blocker, but nondihydropyridine calcium antagonists, such as diltiazem, should be used with caution in those with depressed EF due to their negative inotropic effect. AV node ablation and cardiac resynchronization therapy device placement can be useful when rate control cannot be achieved either because of drug inefficacy or intolerance, as suggested by the 2024 ESC guidelines 1.

From the FDA Drug Label

Diltiazem Hydrochloride Injection or Diltiazem Hydrochloride for Injection are indicated for the following: Atrial Fibrillation or Atrial Flutter Temporary control of rapid ventricular rate in atrial fibrillation or atrial flutter Unless otherwise contraindicated, appropriate vagal maneuvers should be attempted prior to administration of diltiazem hydrochloride injection For either indication and particularly when employing continuous intravenous infusion, the setting should include continuous monitoring of the ECG and frequent measurement of blood pressure. A defibrillator and emergency equipment should be readily available Following administration of one or two intravenous bolus doses of diltiazem hydrochloride injection, response usually occurs within 3 minutes and maximal heart rate reduction generally occurs in 2 to 7 minutes.

To treat emergent Atrial Fibrillation (AFib) with Rapid Ventricular Rate (RVR), the following steps can be taken:

• Attempt vagal maneuvers prior to administration of diltiazem hydrochloride injection, unless otherwise contraindicated.
• Administer diltiazem hydrochloride injection as a bolus dose, with the option for a second dose if necessary.
• Monitor the patient's ECG and blood pressure continuously, with a defibrillator and emergency equipment readily available.
• Be prepared to manage potential hypotension with interventions such as intravenous fluids or the Trendelenburg position, if necessary 2.

From the Research

Treatment Options for Emergent Afib with RVR

• Emergent cardioversion is indicated in hemodynamically unstable patients 3
• Rate or rhythm control should be pursued in hemodynamically stable patients 3
• Rate control using beta blockers or calcium channel blockers should be pursued in those with AF with RVR who do not undergo cardioversion 3, 4

Pharmacologic Management

• Intravenous beta blockers and calcium channel blockers are equally effective in rapidly controlling the ventricular rate in acute AF in selected individuals 4
• The addition of digoxin to the regimen causes a favorable outcome, however, digoxin as a single agent is generally inefficacious in slowing the ventricular rate in acute AF 4
• Diltiazem may be more effective than metoprolol in achieving rapid rate control, but high-quality randomized studies are needed 5
• Metoprolol had a lower failure rate than amiodarone and was superior to diltiazem in achieving rate control at 4 h 6

Anticoagulation and Disposition

• Anticoagulation is an important component of management, and several tools (e.g., CHA2DS2-VASc) are available to assist with this decision 3
• Direct oral anticoagulants are the first-line medication class for anticoagulation 3
• Disposition can be challenging, and several risk assessment tools (e.g., RED-AF, AFFORD, and the AFTER scores) are available to assist with disposition decisions 3