What is the treatment for Premature Atrial Contractions (PACs)?

Treatment for Premature Atrial Contractions (PACs)

Beta blockers are the first-line treatment for symptomatic premature atrial contractions, with metoprolol being a preferred agent starting at 50 mg daily and titrating based on symptom response. 1

Assessment and Diagnosis

• PACs are characterized by early beats originating from the atria, appearing on ECG as premature P waves with abnormal morphology
• Diagnostic evaluation should include:
  • 12-lead ECG to confirm PACs
  • 24-hour Holter monitoring to quantify PAC burden (significant burden is typically >1% of total beats)
  • Echocardiogram to rule out structural heart disease

Treatment Algorithm

Step 1: Assess Symptoms and PAC Burden

• Asymptomatic with minimal PACs: No specific treatment needed 2
• Symptomatic or frequent PACs (>5% burden): Proceed with treatment 3

Step 2: Address Modifiable Triggers

• Reduce or eliminate:
  • Caffeine intake
  • Alcohol consumption
  • Tobacco use
  • Sympathomimetic medications
  • Stress

Step 3: Pharmacological Management

1. First-line therapy: Beta blockers

   • Metoprolol succinate 50 mg once daily, titrate up to 400 mg daily based on response 1
   • Monitor for hypotension, bradycardia, and heart failure symptoms

2. Second-line therapy (if beta blockers ineffective or contraindicated):

   • Non-dihydropyridine calcium channel blockers (e.g., verapamil, diltiazem) 1
   • Flecainide 50 mg twice daily (for PAF patients without structural heart disease), may increase to 100 mg twice daily if needed 4

3. For refractory cases:

   • Consider referral for electrophysiology study and possible catheter ablation 5

Special Considerations

• Hemodynamically unstable patients: Synchronized cardioversion is recommended if PACs trigger sustained arrhythmias 6
• Pre-excited AF triggered by PACs: Ibutilide or IV procainamide for hemodynamically stable patients 6
• Patients with high stroke risk: Evaluate for atrial cardiomyopathy, as frequent PACs are associated with increased risk of atrial fibrillation and stroke 7

Monitoring and Follow-up

• Reassess symptoms after 4 weeks of treatment
• Consider repeat Holter monitoring to objectively assess PAC burden reduction
• Evaluate for progression to sustained arrhythmias (atrial fibrillation, atrial flutter)

Efficacy of Treatment

• Catheter ablation has shown high success rates (>95%) with significant improvement in quality of life in patients with drug-refractory symptomatic PACs 5
• Lifestyle modifications, particularly physical activity and weight management, are associated with lower odds of frequent PACs 8

Caution

• Avoid abrupt discontinuation of beta blockers as this can lead to rebound tachycardia
• Beta blockers should be avoided in patients with significant AV block, decompensated heart failure, or severe bronchospastic disease 1
• Flecainide should be used cautiously in patients with history of CHF or myocardial dysfunction 4

Remember that frequent PACs can impair left atrial contractile function and promote adverse left atrial remodeling, potentially increasing stroke risk 3, making appropriate treatment important for long-term cardiovascular health.