What is the appropriate workup and management for a patient with paroxysmal atrial fibrillation (AFib) in the hospital?

Workup and Management of Paroxysmal Atrial Fibrillation in Hospital

The appropriate workup for paroxysmal atrial fibrillation in the hospital setting should include immediate rate control with a calcium channel blocker (preferably diltiazem) or beta-blocker, anticoagulation assessment based on stroke risk, and consideration for cardioversion if symptoms are severe or hemodynamic compromise is present. 1

Initial Assessment and Stabilization

1. Hemodynamic Assessment:

   • Evaluate for signs of hemodynamic instability (hypotension, angina, acute heart failure, shock)
   • If unstable: Immediate electrical cardioversion is indicated 1
   • If stable: Proceed with rate control and further evaluation

2. Rate Control Strategy:

   • First-line agents:

     • Calcium channel blockers (diltiazem) - achieves rate control faster than beta-blockers 2
     • Beta-blockers (metoprolol) - preferred in patients with heart failure or coronary disease
     • Combination therapy with digoxin and beta-blocker or calcium channel blocker for difficult cases 1

   • Avoid: Digitalis as sole agent for rate control in paroxysmal AF (Class III recommendation) 1

3. 12-lead ECG to:

   • Confirm AF diagnosis
   • Assess for pre-excitation/accessory pathways
   • Evaluate for myocardial ischemia or infarction
   • Identify QT prolongation or conduction abnormalities

Risk Stratification and Anticoagulation

1. Stroke Risk Assessment:

   • Apply CHA₂DS₂-VASc scoring system
   • Initiate anticoagulation for all patients except those with lone AF 1

2. Anticoagulation Protocol:

   • For AF >48 hours or unknown duration: Anticoagulate for 3-4 weeks before and after cardioversion 1
   • For AF <48 hours: May proceed with cardioversion with concurrent heparin 1
   • Alternative approach: TEE to rule out left atrial thrombus before cardioversion 1

3. Anticoagulant Selection:

   • High stroke risk: Oral anticoagulation (INR 2.0-3.0) 1
   • Age ≥75 years: Oral anticoagulation (INR ≥2.0) 1
   • Heart failure, LV ejection fraction ≤0.35, thyrotoxicosis, hypertension, rheumatic heart disease: Oral anticoagulation (INR 2.5-3.5) 1

Rhythm Control Considerations

1. Indications for Cardioversion:

   • Symptomatic AF with unacceptable symptoms 1
   • First episode of AF 1
   • Patients with acute AF and hemodynamic compromise 1

2. Cardioversion Options:

   • Electrical cardioversion: First-line for hemodynamic instability 1
   • Pharmacological cardioversion: Consider for stable patients 1
     • Amiodarone: 5-7 mg/kg IV over 1-2 hours, then 1.2-1.8 g/day 1
     • Flecainide: 200-300 mg oral (if no structural heart disease) 1
     • Propafenone: 450-600 mg oral (if no structural heart disease) 1

3. Maintenance Therapy:

   • Base selection on safety profile and patient characteristics 1
   • Consider "pill-in-the-pocket" approach for selected patients with infrequent episodes 1

Laboratory and Imaging Workup

1. Laboratory Tests:

   • Complete blood count
   • Electrolytes, renal function
   • Thyroid function tests (hyperthyroidism is common trigger)
   • Cardiac biomarkers if ischemia suspected

2. Imaging Studies:

   • Echocardiography to assess:
     • Left atrial size
     • Valvular disease
     • Left ventricular function
     • Structural heart disease
   • Transesophageal echocardiography if cardioversion planned and duration >48 hours 1

Common Pitfalls and Caveats

• Do not use digitalis as sole agent for rate control in paroxysmal AF 1
• Do not perform catheter ablation without prior medical therapy 1
• Do not cardiovert without appropriate anticoagulation if AF duration >48 hours 1
• Beware of pre-excited AF (with accessory pathway) - avoid AV nodal blocking agents and consider immediate cardioversion 1
• Monitor for proarrhythmic effects of antiarrhythmic drugs, especially in patients with structural heart disease

Hospital Discharge Planning

1. Follow-up anticoagulation plan:

   • INR monitoring schedule (weekly during initiation, monthly when stable) 1
   • Reassess anticoagulation needs regularly 1

2. Long-term management strategy:

   • Rate control vs. rhythm control based on symptom burden and patient factors 3
   • Consider early rhythm control with antiarrhythmic drugs or catheter ablation for symptomatic patients 3

3. Risk factor modification:

   • Address modifiable risk factors (hypertension, obesity, sleep apnea, alcohol intake) 3
   • Lifestyle counseling (weight loss, exercise) 3