What is the management of atrial flutter in an inpatient requiring a rapid response?

From the Guidelines

Management of a flutter inpatient rapid response requires immediate assessment and intervention, with synchronized cardioversion recommended for acute treatment of patients with atrial flutter who are hemodynamically unstable and do not respond to pharmacological therapies. The first step is to ensure the patient is hemodynamically stable by checking vital signs. If the patient is unstable with hypotension or signs of poor perfusion, proceed with immediate synchronized cardioversion at 50-100 joules, as recommended by the 2015 ACC/AHA/HRS guideline for the management of adult patients with supraventricular tachycardia 1.

For stable patients, begin rate control with intravenous beta-blockers such as metoprolol or diltiazem, as they are useful for acute rate control in patients with atrial flutter who are hemodynamically stable, according to the guideline 1. Obtain a 12-lead ECG to confirm atrial flutter diagnosis, looking for the characteristic sawtooth pattern. Order basic labs including electrolytes, CBC, and cardiac enzymes. Consider anticoagulation with heparin or enoxaparin if the duration of flutter is unknown or greater than 48 hours to prevent thromboembolism, as acute antithrombotic therapy is recommended in patients with atrial flutter to align with recommended antithrombotic therapy for patients with AF 1.

Some key points to consider in the management of atrial flutter include:

• Oral dofetilide or intravenous ibutilide is useful for acute pharmacological cardioversion in patients with atrial flutter 1
• Elective synchronized cardioversion is indicated in stable patients with well-tolerated atrial flutter when a rhythm-control strategy is pursued 1
• Rapid atrial pacing is useful for acute conversion of atrial flutter in patients who have pacing wires in place as part of a permanent pacemaker or implantable cardioverter-defibrillator or for temporary atrial pacing after cardiac surgery 1
• Intravenous amiodarone can be useful for acute control of the ventricular rate in patients with atrial flutter and systolic heart failure, when beta blockers are contraindicated or ineffective 1

Identify and treat underlying causes such as electrolyte abnormalities, hypoxia, or cardiac ischemia. Atrial flutter occurs due to a macro-reentrant circuit, typically in the right atrium, causing rapid atrial rates of 250-350 beats per minute with variable ventricular response depending on AV node conduction.

From the FDA Drug Label

Ibutilide fumarate injection is indicated for the rapid conversion of atrial fibrillation or atrial flutter of recent onset to sinus rhythm. Among patients with atrial flutter, 53% receiving 1 mg ibutilide fumarate and 70% receiving 2 mg ibutilide fumarate converted, compared to 18% of those receiving sotalol Conversion of atrial flutter/ fibrillation usually (70% of those who converted) occurred within 30 minutes of the start of infusion and was dose related.

Management of a flutter inpatient rapid response:

• Ibutilide fumarate injection can be used for the rapid conversion of atrial flutter to sinus rhythm.
• The conversion rate for atrial flutter is around 53-70% with ibutilide fumarate injection, depending on the dose.
• Conversion usually occurs within 30 minutes of the start of infusion.
• Monitoring with continuous ECG for at least 4 hours following infusion is required to anticipate and manage potential proarrhythmic events 2, 2.
• Skilled personnel and equipment, including cardiac monitoring equipment and a cardioverter/defibrillator, must be available during and after administration of ibutilide fumarate injection 2.

From the Research

Management of Atrial Flutter

• Atrioventricular node blocking agents, including beta-adrenergic blockers, non-dihydropyridine calcium channel blockers, and digoxin, are usually effective in controlling ventricular rate in atrial fibrillation and flutter 3.
• Intravenous beta-blockers and non-dihydropyridine calcium channel blockers are equally effective in rapidly controlling the ventricular rate 3.
• The choice of agent depends on the clinical situation, with beta-blockers preferred in patients with myocardial ischemia, myocardial infarction, and hyperthyroidism, but avoided in patients with bronchial asthma and chronic obstructive pulmonary disease 3.

Cardioversion of Atrial Flutter

• Cardioversion is widely used in patients with atrial fibrillation and atrial flutter when a rhythm control strategy is pursued 4.
• Biphasic shocks have been shown to be superior to monophasic shocks for external cardioversion of atrial flutter, with greater efficacy and lower mean delivered energy 5.
• The use of biphasic cardioversion with lower starting energies is recommended for transthoracic cardioversion of typical atrial flutter 5.

Pharmacological Management

• Diltiazem and metoprolol are both commonly used to treat atrial fibrillation/flutter in the emergency department, with diltiazem shown to be more effective in achieving rate control 6.
• The effectiveness of diltiazem and metoprolol for rate control of atrial fibrillation/flutter has been compared in several studies, with varying results 7, 6.
• The choice of pharmacological agent depends on the individual patient's clinical situation and medical history 3, 7, 6.

Inpatient Rapid Response

• The management of atrial flutter with rapid ventricular response in patients with acute decompensated heart failure is a complex issue, with limited high-level evidence to inform clinical decision making 7.
• A systematic review of observational studies and randomized clinical trials found that the overall risk of bias for included studies ranged from serious to critical, and that missing data and heterogeneity of definitions precluded the combination of results for quantitative meta-analysis 7.