What is the management approach for an older adult with a history of Chronic Obstructive Pulmonary Disease (COPD) presenting with multifocal atrial tachycardia?

Management of Multifocal Atrial Tachycardia

The cornerstone of managing multifocal atrial tachycardia (MAT) is treating the underlying pulmonary disease and correcting metabolic abnormalities—particularly hypoxemia, acidosis, and electrolyte imbalances—before attempting any antiarrhythmic therapy. 1, 2

Initial Management: Address Underlying Causes First

Correction of precipitating factors is the Class I recommendation and must be the first step, as antiarrhythmic therapy and cardioversion are ineffective until the underlying condition is stabilized 1, 2:

• Optimize treatment of COPD exacerbation with bronchodilators, corticosteroids, and oxygen therapy to correct hypoxemia 1, 2
• Correct hypoxemia and acidosis immediately—this is a Class I recommendation for patients with acute pulmonary illness 1
• Replete magnesium aggressively, even if serum levels are normal, as hypomagnesemia is a common precipitant 2, 3
• Correct hypokalemia if present 2
• Discontinue or reduce theophylline if the patient is receiving it, as this commonly precipitates MAT 1, 2
• Avoid or minimize β-adrenergic agonists when possible, as these can trigger MAT 1

Acute Pharmacologic Management

Once stabilization measures are underway, rate control can be attempted if the patient remains symptomatic:

First-Line Agents (Class IIa Recommendations)

Non-dihydropyridine calcium channel blockers are the preferred agents for rate control in COPD patients with MAT 1:

• Intravenous verapamil can terminate MAT in approximately 50% of patients (8 of 16 in one study) and provides rate control in others 1, 4

  • Monitor closely for hypotension, which is the major side effect 1, 5
  • Contraindicated in patients with ventricular dysfunction, sinus node dysfunction, AV block, or hemodynamic instability 1, 2

• Intravenous metoprolol is an alternative that can achieve conversion to sinus rhythm in 68% of patients 1, 6

  • Use the cardioselective β-1 blocker metoprolol rather than non-selective agents 1
  • Use with extreme caution in COPD patients, particularly those with active bronchospasm 1
  • Should only be used after correction of hypoxia and respiratory decompensation 1, 6
  • Mean effective IV dose is approximately 6.5 mg 6

Critical Contraindications

Never use the following agents in MAT patients with obstructive lung disease (Class III recommendation) 1:

• Non-selective β-blockers
• Sotalol
• Propafenone
• Adenosine

Do not attempt electrical cardioversion—it is not effective for MAT 1, 2

Hemodynamic Instability

If the patient becomes hemodynamically unstable, direct current cardioversion should be attempted (Class I recommendation), though it is generally ineffective for MAT 1. Focus instead on aggressive treatment of the underlying cause and supportive measures.

Ongoing Management for Recurrent MAT

For patients with recurrent symptomatic MAT after hospital discharge:

• Oral verapamil or diltiazem for rate control (Class IIa recommendation) 1, 2

  • Verapamil has the advantage of not exacerbating pulmonary disease 1
  • Avoid in patients with severe conduction abnormalities or sinus node dysfunction 1, 2

• Oral metoprolol is reasonable as an alternative (Class IIa recommendation) 1, 2

  • Can be used for maintenance after demonstrating tolerability during acute phase 6
  • Mean effective oral dose is approximately 32.5 mg 6

Important Clinical Pearls

• MAT is commonly mistaken for atrial fibrillation—the key distinguishing feature is the presence of at least 3 distinct P-wave morphologies with isoelectric baseline between P waves 2, 7
• MAT typically occurs in elderly patients with severe COPD and carries adverse prognostic implications during acute exacerbations 1, 3
• The mechanism likely involves triggered activity from delayed afterdepolarizations, which explains why cardioversion fails 1, 3, 7
• Both β-blockers and calcium channel blockers should be avoided in acute decompensated heart failure 1, 2
• Small doses of β-1 selective blockers (bisoprolol) can be considered as alternatives for rate control (Class IIa) 1