What is the management of intraoperative atrial fibrillation (AF) with rapid ventricular response in an adult patient with possible underlying cardiovascular disease?

Management of Intraoperative Atrial Fibrillation with Rapid Ventricular Response

For hemodynamically unstable patients with intraoperative AF and RVR, perform immediate direct-current cardioversion; for hemodynamically stable patients, use intravenous beta-blockers (metoprolol or esmolol) as first-line therapy if left ventricular function is preserved, or intravenous amiodarone if heart failure or significant LV dysfunction is present. 1, 2

Initial Assessment: Hemodynamic Stability

Immediately assess for signs of hemodynamic compromise:

• Symptomatic hypotension (systolic BP <90 mmHg with symptoms) 2, 3
• Ongoing myocardial ischemia or angina 1, 2
• Acute heart failure or pulmonary edema 2, 3
• Altered mental status from hypoperfusion 2

If any of these are present, proceed directly to electrical cardioversion without attempting pharmacologic rate control. 1, 2

Hemodynamically Stable Patients: Rate Control Strategy

Step 1: Assess Left Ventricular Function and Comorbidities

For patients with preserved ejection fraction (LVEF >40%) and no decompensated heart failure:

• Administer intravenous beta-blockers as first-line therapy 1, 2, 3
  • Esmolol is specifically FDA-approved for rapid control of ventricular rate in perioperative AF and offers the advantage of ultra-short half-life (9 minutes), allowing rapid titration and reversal if hypotension develops 4
  • Metoprolol 2.5-5 mg IV bolus over 2 minutes, may repeat every 5 minutes up to 15 mg total 2, 3
• Alternative: Intravenous diltiazem or verapamil if beta-blockers are contraindicated (e.g., bronchospasm, severe COPD) 1, 2, 3
  • Diltiazem 0.25 mg/kg IV over 2 minutes, followed by continuous infusion 5

For patients with reduced ejection fraction (LVEF ≤40%) or decompensated heart failure:

• Intravenous amiodarone is the preferred agent 1, 6
  • Loading dose: 150 mg IV over 10 minutes, followed by 1 mg/min for 6 hours, then 0.5 mg/min for 18 hours 7
  • Amiodarone provides both rate control and rhythm control effects, with low proarrhythmic risk 1, 7
• Alternative: Intravenous digoxin (onset slower, 30-60 minutes) 1, 3
• Do NOT use intravenous beta-blockers or calcium channel blockers in decompensated heart failure 1, 3

Step 2: Target Heart Rate

Aim for ventricular rate <110 beats per minute at rest 2, 3

• More aggressive targets (60-80 bpm) may be needed if patient remains symptomatic or has ongoing ischemia 2

Step 3: Combination Therapy if Single Agent Fails

If monotherapy inadequate, add digoxin to beta-blocker or calcium channel blocker 1, 2, 3

• Digoxin loading: 0.25 mg IV every 2 hours up to 1.5 mg total 3

Critical Special Situations in the Intraoperative Setting

Wolff-Parkinson-White Syndrome with Pre-excitation

If wide QRS complexes (≥120 ms) are present on ECG, suspect WPW:

• DO NOT administer AV nodal blocking agents (beta-blockers, calcium channel blockers, digoxin, or adenosine) as these can precipitate ventricular fibrillation 1, 2, 3
• For hemodynamically unstable WPW patients: immediate cardioversion 1, 3
• For hemodynamically stable WPW patients: intravenous procainamide (15 mg/kg over 30-60 minutes) or ibutilide 1, 2

Acute Myocardial Infarction or Active Ischemia

Use intravenous beta-blockers or amiodarone 1

• Beta-blockers provide dual benefit of rate control and anti-ischemic effects 1
• Avoid if clinical LV dysfunction, bronchospasm, or AV block present 1
• Initiate unfractionated heparin unless contraindicated 1

Suspected Tachycardia-Induced Cardiomyopathy

If new heart failure presentation with AF-RVR, presume rate-related cardiomyopathy until proven otherwise:

• Either aggressive rate control OR rhythm control (cardioversion) is reasonable 1, 2
• Amiodarone provides both rate and rhythm control, making it ideal in this scenario 1
• LV function typically recovers within 6 months of adequate rate or rhythm control 2

Anticoagulation Considerations

Assess stroke risk and initiate anticoagulation:

• Administer unfractionated heparin intraoperatively unless active bleeding or high bleeding risk 1, 6
• Calculate CHA₂DS₂-VASc score postoperatively to guide long-term anticoagulation 2, 3

Common Pitfalls to Avoid

Do not use digoxin as monotherapy for acute rate control - it is ineffective for controlling ventricular rate during acute AF with high sympathetic tone (as occurs intraoperatively) 8, 9

Avoid beta-blockers in patients with:

• Decompensated heart failure or overt pulmonary congestion 1, 3
• Severe bronchospasm or active asthma exacerbation 1
• High-degree AV block 1

Monitor for excessive bradycardia - particularly when combining rate-control agents or in elderly patients 2

If patient has history of atrial flutter, co-administer AV nodal blocker with any antiarrhythmic agent to prevent 1:1 AV conduction and paradoxical acceleration of ventricular rate 2