What helps with atrial fibrillation (AFib) with rapid ventricular response (RVR) without causing hypotension (low blood pressure)?

From the Guidelines

For atrial fibrillation with rapid ventricular response (AFib with RVR) without dropping blood pressure, calcium channel blockers like diltiazem or beta-blockers such as metoprolol are typically first-line treatments, as recommended by the 2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation 1. These medications slow conduction through the AV node, reducing heart rate while generally preserving blood pressure. The choice between these agents depends on the patient's specific clinical context, including the presence of heart failure or hypotension concerns. For patients with hypotension concerns, amiodarone may be preferred as it has less negative inotropic effect, although its use should be guided by the clinical scenario and patient factors, as outlined in the guidelines 1. Digoxin can also be considered, particularly in patients with heart failure, though it works more slowly and its use is supported by guidelines for controlling resting heart rate in patients with heart failure 1. These medications work by modulating electrical conduction pathways in the heart, specifically slowing conduction through the AV node, which reduces the number of atrial impulses that reach the ventricles, thereby controlling ventricular rate without significantly reducing cardiac output or blood pressure. Key considerations in the management of AFib with RVR include assessing the need for immediate cardioversion, evaluating the patient's hemodynamic stability, and selecting the most appropriate pharmacological agent based on the patient's clinical profile, as emphasized in the guidelines 1. In clinical practice, the selection of a specific medication should be tailored to the individual patient, taking into account factors such as the presence of heart failure, the risk of hypotension, and the potential for drug interactions, with the goal of optimizing outcomes in terms of morbidity, mortality, and quality of life.

From the FDA Drug Label

Verapamil reduces afterload and myocardial contractility The commonly used intravenous doses of 5 to 10 mg verapamil hydrochloride produce transient, usually asymptomatic, reduction in normal systemic arterial pressure, systemic vascular resistance and contractility; left ventricular filling pressure is slightly increased In most patients, including those with organic cardiac disease, the negative inotropic action of verapamil is countered by reduction of afterload, and cardiac index is usually not reduced. This effect results in a reduction of the ventricular rate in patients with atrial flutter and/or atrial fibrillation and a rapid ventricular response

Verapamil can help with AFib RVR without significantly dropping BP in most patients, including those with organic cardiac disease, as the negative inotropic action is countered by reduction of afterload 2.

• Key points:
  • Reduces afterload and myocardial contractility
  • Transient, usually asymptomatic, reduction in normal systemic arterial pressure
  • Cardiac index is usually not reduced
  • Reduces ventricular rate in patients with AFib RVR

From the Research

Agents for Rate Control in Atrial Fibrillation with Rapid Ventricular Response

• Calcium channel blockers and β-blockers are effective for rate control in atrial fibrillation with rapid ventricular response (RVR) 3, 4.
• Diltiazem and metoprolol are commonly used agents, with diltiazem likely achieving rate control faster than metoprolol 3.
• The choice of agent should consider the individual patient, clinical situation, and comorbidities 3.

Comparison of Agents

• A study comparing intravenous diltiazem, metoprolol, and verapamil found no statistically significant difference in achieving rate control at 1 hour 5.
• Another study found that metoprolol had a lower failure rate than amiodarone and was superior to diltiazem in achieving rate control at 4 hours 6.
• In patients with heart failure with reduced ejection fraction (HFrEF), there was no difference in total adverse events between diltiazem and metoprolol, but diltiazem had a higher incidence of worsening heart failure symptoms 7.

Considerations for Blood Pressure

• Calcium channel blockers, such as diltiazem, can have negative inotropic effects and should be avoided in patients with HFrEF 7.
• Beta blockers, such as metoprolol, may be a better option for patients with HFrEF, but can cause hypotension and bradycardia 7.
• The choice of agent should balance the need for rate control with the risk of adverse effects, including hypotension 4, 7.