Treatment of Multifocal Atrial Tachycardia During COPD Exacerbation
The primary treatment of multifocal atrial tachycardia (MAT) during COPD exacerbation is correction of the underlying respiratory decompensation—specifically hypoxemia and acidosis—rather than direct antiarrhythmic therapy, as MAT will typically resolve once the pulmonary condition improves. 1
Initial Management Priority: Treat the Underlying COPD Exacerbation
The European Society of Cardiology explicitly states that MAT is common in severe COPD and may be mistaken for atrial fibrillation, and that correction of hypoxemia and acidosis is the recommended initial management for patients who develop arrhythmias during acute pulmonary illness. 1 Treatment of the underlying pulmonary disease and correction of metabolic imbalance are the primary considerations, as antiarrhythmic therapy and electrical cardioversion are likely to be ineffective until respiratory decompensation has been corrected. 1
Standard COPD Exacerbation Treatment
Bronchodilators: Administer short-acting β-agonists (salbutamol/albuterol) and/or ipratropium via MDI with spacer or nebulizer. 2, 3
Systemic corticosteroids: Give prednisone 30-40 mg orally daily for 5-7 days (or equivalent dose if intravenous route needed). 2, 3
Antibiotics: Initiate if patient has altered sputum characteristics (increased purulence and/or volume). 2, 3
Oxygen therapy: Target PaO₂ >60 mmHg or SpO₂ >90%, using controlled oxygen delivery to prevent worsening hypercapnia. 2, 3
Rate Control Strategies (If Needed After Treating Underlying Condition)
If MAT persists despite optimizing the respiratory status, or if rate control is urgently needed due to hemodynamic compromise:
First-Line Rate Control Agent
Non-dihydropyridine calcium channel antagonists (diltiazem or verapamil) should be considered as the preferred agents for ventricular rate control in patients with obstructive pulmonary disease who develop MAT. 1 These agents do not cause bronchospasm, unlike many other rate-controlling medications.
Alternative Rate Control Option
β-1 selective blockers (e.g., bisoprolol or metoprolol) in small doses should be considered as an alternative for ventricular rate control. 1 Research evidence supports metoprolol's effectiveness, showing dramatic heart rate slowing (average 54 beats/min reduction) with 68% conversion to sinus rhythm, without clinically apparent hemodynamic or respiratory deterioration. 4 Notably, PaO₂ actually increased by an average of 12.2 torr with metoprolol administration. 4
Electrolyte Repletion
Magnesium and potassium supplementation should be considered, as patients with MAT often have deficiencies. 5 Intravenous magnesium sulfate (7-12 gm over 5 hours) with potassium supplements successfully converted MAT to sinus rhythm in 7 of 8 patients in one study. 5
Refractory Cases
Amiodarone may be considered for refractory MAT when other measures fail. 6 Intravenous amiodarone (450-900 mg over 2 hours) or oral amiodarone (600 mg/day initially, then 200-400 mg/day maintenance) achieved sinus rhythm restoration in small case series. 6
Critical Contraindications
Avoid the following agents in COPD patients with MAT:
Non-selective β-blockers, sotalol, propafenone, and adenosine are not recommended in patients with obstructive lung disease who develop arrhythmias. 1
Theophylline and β-adrenergic agonist agents are not recommended in patients with bronchospastic lung disease who develop MAT, as these agents may precipitate or worsen the arrhythmia. 1
Hemodynamic Instability
Direct current cardioversion should be attempted in patients with pulmonary disease who become hemodynamically unstable as a consequence of the arrhythmia. 1 However, this is rarely necessary for MAT specifically, as it typically responds to treatment of the underlying condition.
Prognostic Considerations
MAT carries significant prognostic implications in COPD patients. 7 In mechanically ventilated COPD patients, 87% of those with MAT expired during ICU admission compared to 23.5% without MAT, suggesting MAT is a marker of severe disease. 7 This underscores the importance of aggressive treatment of the underlying respiratory failure rather than focusing solely on the arrhythmia.
Diagnostic Note
The rate threshold for diagnosing MAT should be 90 beats/min rather than the conventional 100 beats/min, as this lower threshold shows better association with COPD exacerbations. 8