Atrial Fibrillation Management

Introduction to Atrial Fibrillation Control

The European Society of Cardiology recommends metoprolol over digoxina for controlling heart rate in unstable atrial fibrillation due to its rapid onset of action and greater effectiveness in states of elevated sympathetic tone 1
Beta-blockers like metoprolol are preferred for acute heart rate control in unstable atrial fibrillation because they have a faster onset of action than digoxina, are more effective in states of elevated sympathetic tone, and can be administered intravenously in doses of 2.5-10 mg as a bolus (which can be repeated as needed) 1

The European Society of Cardiology suggests that digoxina has several disadvantages for acute heart rate control in unstable atrial fibrillation, including a slower onset of action (approximately 2 hours), limited efficacy during states of elevated sympathetic tone, and insufficient heart rate control during exercise or stress 1, 2
First-line treatment for acute heart rate control in unstable atrial fibrillation is metoprolol IV (2.5-10 mg as a bolus, repeatable as needed) 1
Alternative therapy includes diltiazem or verapamilo IV if there are contraindications to beta-blockers 1
Combination therapy with digoxina should be considered if control with monotherapy is insufficient 1
In cases of severe ventricular dysfunction, amiodarone IV may be used in patients with hemodynamic instability or severe ventricular dysfunction 1

In patients with severe ventricular dysfunction, calcium channel blockers (diltiazem/verapamilo) are contraindicated 1
The combination of beta-blockers and digoxina produces a synergistic effect on the AV node, improving heart rate control 2
Metoprolol controls heart rate better during exercise than digoxina alone 2

Potential side effects of beta-blockers include hypotension, bradycardia, heart block, and exacerbation of heart failure 4
Precautions should be taken in patients with asthma or COPD (preferably using cardioselective agents) 1
Digoxina toxicity can lead to heart block, bradycardia, and increased risk of death, especially with elevated plasma levels, and requires dose adjustment in patients with renal insufficiency 1, 2
Monitoring should include evaluating heart rate at rest and during activity, ECG to detect conduction anomalies, and vigilance for signs of hypotension or worsening heart failure 1

In cases of severe hemodynamic instability, urgent electrical cardioversion should be considered as a definitive treatment 1