What is the management of hypotension in atrial fibrillation (AF)?

From the Guidelines

Management of shock in atrial fibrillation requires immediate cardioversion and hemodynamic stabilization, prioritizing the patient's safety and preventing further morbidity and mortality. For patients with AF-induced shock, perform synchronized electrical cardioversion at 120-200 joules biphasic (or 200 joules monophasic) without delay, as recommended by the latest guidelines 1. Prior to cardioversion, administer sedation if the patient is conscious and time permits, using medications like midazolam (1-2 mg IV) or etomidate (0.1-0.3 mg/kg IV). Simultaneously, address the underlying shock with IV fluids (crystalloids at 20-30 ml/kg) and vasopressors if needed, with norepinephrine (starting at 0.1-0.5 mcg/kg/min) being the preferred agent.

After cardioversion, initiate rate control with cautious doses of beta-blockers (metoprolol 2.5-5 mg IV) or calcium channel blockers (diltiazem 5-10 mg IV) once hemodynamic stability is achieved, considering the patient's underlying heart function and comorbidities 1. For long-term management, anticoagulation should be started based on stroke risk assessment using the CHA₂DS₂-VASc score, as outlined in the 2024 ESC guidelines for the management of atrial fibrillation 1. The aggressive approach to immediate cardioversion is justified because AF with shock represents a life-threatening emergency where the rapid, irregular heart rate compromises cardiac output, further exacerbating hypotension and end-organ hypoperfusion, creating a dangerous cycle that requires prompt intervention.

Key considerations in the management of shock in atrial fibrillation include:

• Immediate cardioversion to restore a stable heart rhythm
• Hemodynamic stabilization with IV fluids and vasopressors as needed
• Rate control with beta-blockers or calcium channel blockers after cardioversion
• Long-term anticoagulation based on stroke risk assessment
• Comprehensive management of underlying comorbidities and risk factors, as emphasized in the 2024 ESC guidelines 1.

By prioritizing the patient's safety and following the latest guidelines, healthcare providers can effectively manage shock in atrial fibrillation, reducing morbidity and mortality, and improving quality of life.

From the FDA Drug Label

In clinical trials, treatment-emergent, drug-related hypotension was reported as an adverse effect in 288 (16%) of 1836 patients treated with intravenous amiodarone Treat hypotension initially by slowing the infusion; additional standard therapy may be needed, including the following: vasopressor drugs, positive inotropic agents, and volume expansion.

The management of shock in atrial fibrillation with amiodarone (IV) involves treating hypotension by:

• Slowing the infusion
• Using vasopressor drugs
• Using positive inotropic agents
• Implementing volume expansion 2

From the Research

Management of Shock in Atrial Fibrillation

• Atrial fibrillation (AF) is common in ICU patients and is associated with a two- to fivefold increase in mortality 3.
• AF can cause hypotension and heart failure with subsequent organ dysfunction, and the underlying mechanisms are the loss of atrial contraction and the high ventricular rate 3.
• In unstable patients, sinus rhythm must be rapidly restored by synchronised electrical cardioversion (ECV), and if pharmacological treatment is indicated, clinicians can choose between the rate control and the rhythm control strategy 3, 4.
• A beta-1 antagonist with a very short half-life (e.g., esmolol) is an advantage for ICU patients because the effect of beta-blockade on cardiovascular stability is unpredictable in those patients 3.
• Amiodarone is commonly used in the ICU setting but has potentially severe cardiac and noncardiac side effects, and digoxin controls the ventricular response at rest, but its benefit decreases in the presence of adrenergic stress 3.
• Vernakalant converts new-onset AF to sinus rhythm in approximately 50% of patients, but data on its efficacy and safety in critically ill patients are lacking 3, 4.

Treatment Strategies

• The initial management includes the evaluation of the hemodynamic consequences of new-onset atrial fibrillation and the optimization of reversible causes 4.
• In patients with hemodynamic instability, the rapid restoration of an adequate perfusion pressure is the initial goal, and often, a rapid conversion in sinus rhythm is required to achieve hemodynamic stabilization 4.
• Electrical cardioversion, if possible performed after pretreatment with an antiarrhythmic drug to increase the success rate, frequently plays a central role in the conversion to sinus rhythm of hemodynamically unstable patients 4.
• Stable patients are initially treated with a short-acting intravenous β-blocker to achieve heart rate control, and a conversion to sinus rhythm may be achieved pharmacologically with vernakalant, an atrial-specific multichannel blocker 4.

Anticoagulation and Thromboembolic Risk

• All patients with atrial fibrillation lasting more than 48 h should be evaluated for anticoagulation in order to reduce cardio-embolic complications 4, 5.
• Atrial fibrillation and heart failure with reduced ejection fraction are associated with worse outcomes, including an increased risk of stroke, and requiring oral anticoagulation in many or left atrial appendage closure in some 6.