What are the drugs and doses used to treat atrial flutter?

Drugs for Atrial Flutter with Doses

Rate Control Medications

For acute rate control in hemodynamically stable atrial flutter, beta-blockers, diltiazem, or verapamil are the first-line agents, though achieving adequate rate control is more challenging than in atrial fibrillation due to less concealed AV nodal conduction. 1, 2

Beta-Blockers (Preferred in Most Patients)

• Metoprolol tartrate: 2.5-5 mg IV bolus over 2 minutes; up to 3 doses. Oral maintenance: 25-100 mg twice daily 1
• Esmolol (preferred for acute situations due to rapid onset): 500 mcg/kg IV bolus over 1 minute, then 50-300 mcg/kg/min continuous infusion 1, 2
• Metoprolol succinate (XL): 50-400 mg once daily (oral only) 1
• Propranolol: 1 mg IV over 1 minute, up to 3 doses at 2-minute intervals. Oral: 10-40 mg three to four times daily 1
• Atenolol: 25-100 mg once daily (oral only, renally eliminated) 1
• Bisoprolol: 2.5-10 mg once daily (oral only) 1
• Carvedilol: 3.125-25 mg twice daily (oral only) 1
• Nadolol: 10-240 mg once daily (oral only) 1

Nondihydropyridine Calcium Channel Blockers

• Diltiazem (preferred IV calcium channel blocker due to superior safety and efficacy): 0.25 mg/kg IV bolus over 2 minutes, may repeat 0.35 mg/kg over 2 minutes, then 5-15 mg/h continuous infusion. Oral maintenance: 120-360 mg once daily (extended release) 1, 2
• Verapamil: 0.075-0.15 mg/kg (5-10 mg) IV bolus over 2 minutes, may give additional 10 mg after 30 minutes if no response, then 0.005 mg/kg/min (5 mg/h) infusion. Oral: 180-480 mg once daily (extended release) 1

Critical caveat: Avoid nondihydropyridine calcium channel blockers in decompensated heart failure, advanced heart block, sinus node dysfunction without pacemaker, or pre-excitation syndromes 1, 2

Digoxin

• Digoxin: 0.25 mg IV with repeat dosing to maximum of 1.5 mg over 24 hours. Oral maintenance: 0.125-0.25 mg once daily 1
• Digoxin is generally less effective as monotherapy for rate control in active patients and should not be used alone 3
• Renally eliminated; increased mortality at plasma concentrations exceeding 1.2 ng/mL 1

Amiodarone (Second-Line for Rate Control)

• Amiodarone: 150-300 mg IV over 1 hour, then 10-50 mg/h over 24 hours. Oral maintenance: 100-200 mg once daily (loading dose 6-10 g over 2-4 weeks) 1
• May be useful for rate control when other measures are unsuccessful or contraindicated, particularly in systolic heart failure when beta-blockers are contraindicated 1, 2

Important consideration: Higher doses of rate-control medications, and often combination therapy, are typically needed in atrial flutter compared to atrial fibrillation because the slower atrial rate paradoxically results in more rapid AV nodal conduction 1, 2

Rhythm Control Medications (Acute Cardioversion)

Ibutilide and dofetilide are the first-line pharmacological agents for acute cardioversion of atrial flutter, with class III drugs being more effective than class I agents for flutter conversion. 4, 5

Class III Antiarrhythmic Drugs (First-Line)

• Ibutilide (IV only): Requires continuous electrocardiographic monitoring for at least 4 hours after infusion or until QTc returns to baseline to minimize risk of torsades de pointes 1, 4

  • Correct hypokalemia and hypomagnesemia before administration 1

• Dofetilide (oral): Requires hospitalization for initiation with continuous ECG monitoring 1, 4

  • Baseline and follow-up testing includes 12-lead ECG, serum creatinine for creatinine clearance estimation, serum potassium and magnesium every 3-6 months 1

Class IC Antiarrhythmic Drugs (For Patients Without Structural Heart Disease)

• Flecainide: Starting dose 50 mg every 12 hours for paroxysmal atrial flutter. May increase in 50 mg twice daily increments every 4 days. Maximum 300 mg/day for supraventricular arrhythmias 4, 6

  • Critical warning: Can cause 1:1 AV conduction in atrial flutter, potentially increasing ventricular rate; concomitant AV nodal blocking agents are mandatory 1, 4, 7, 6
  • Contraindicated in structural heart disease 4, 7, 6

• Propafenone: Starting dose 150 mg every 8 hours or 225 mg every 12 hours (extended release). Usual dose 450-900 mg/day in divided doses 7

  • Same critical warning regarding 1:1 conduction as flecainide; requires concomitant AV nodal blockade 1, 4, 7
  • Contraindicated in structural heart disease 7

Major pitfall: Class IC drugs (flecainide, propafenone) can paradoxically increase ventricular rate in atrial flutter by organizing flutter to a slower atrial rate that conducts 1:1 through the AV node. Always combine with beta-blockers or calcium channel blockers 1, 4, 7, 6

Long-Term Rhythm Control (Maintenance Therapy)

For patients without structural heart disease, first-choice antiarrhythmic drugs include dronedarone, flecainide, propafenone, or sotalol 3

• Sotalol: Requires hospitalization for initiation with continuous ECG monitoring. Follow-up includes 12-lead ECG, serum creatinine, potassium and magnesium every 3-6 months 1
• Dronedarone: Baseline and follow-up AST/ALT within first 6 months, 12-lead ECG 1
• Amiodarone: Only drug recommended for patients with left ventricular ejection fraction <35% 3

Special Considerations

Pre-Excitation Syndromes (Wolff-Parkinson-White)

Avoid digoxin, nondihydropyridine calcium channel blockers, beta-blockers, and amiodarone in pre-excited atrial flutter, as these can accelerate conduction through the accessory pathway and precipitate ventricular fibrillation. 1, 8

• Procainamide is the drug of choice for atrial flutter with pre-excitation 8
• Requires ECG monitoring during infusion for QRS widening, QTc prolongation, and blood pressure monitoring for hypotension 1, 8

Hemodynamic Instability

Immediate synchronized cardioversion is indicated for hemodynamically unstable patients (hypotension, acute heart failure, ongoing chest pain, altered mental status) who don't respond to pharmacological therapies. 1, 2

• Atrial flutter typically requires lower energy levels than atrial fibrillation 1, 2

Anticoagulation Requirements

Anticoagulation protocols for atrial flutter must follow the same guidelines as atrial fibrillation, with therapeutic anticoagulation for at least 3 weeks before and 4 weeks after cardioversion for flutter ≥48 hours or unknown duration. 1, 4, 2

• Stroke risk in atrial flutter is approximately 3% annually 2
• For flutter <48 hours with high stroke risk, IV heparin, LMWH, or direct oral anticoagulants should be initiated before or immediately after cardioversion 1

Definitive Treatment Consideration

Catheter ablation of the cavotricuspid isthmus should be strongly considered as first-line therapy for symptomatic atrial flutter or flutter refractory to pharmacological rate control, with success rates exceeding 90% and low complication rates. 1, 4, 2

• This is particularly important because 22-50% of patients develop atrial fibrillation within 14-30 months after successful CTI ablation 4, 2