Multifocal atrial tachycardia

Background

  • Multiple (3 or more) ectopic foci in the atria causing an irregular atrial tachycardia
  • Increased automaticity due to causes listed below

Causes

Clinical Features

  • Palpitations
  • Dyspnea
  • Chest pain
  • Presyncope/syncope
Multifocal atrial tachycardia

Differential Diagnosis

Narrow-complex tachycardia

Palpitations

Evaluation

  • ECG
    • Irregular tachycardia (>100 bpm)
    • At least 3 distinct p wave morphologies
    • No dominant pacemaker site
  • BMP, Magnesium
  • Hemoglobin/hematocrit
  • Consider infectious disease work up
  • Consider ABG/VBG

Management

  • Treat underlying cause
  • Replace magnesium
  • Replace potassium
  • Increased AV nodal activity is unlikely to be effective
    • Vagal maneuvers and adenosine may help reveal underlying rhythm/p-waves
    • Can consider beta-blocker or calcium channel blocker in hemodynamically stable patient
      • Use beta-blockers cautiously in patients with pulmonary disease
  • Cardioversion not definitive
    • MAT likely to recur if underlying etiology not addressed

Disposition

  • Disposition depends on underlying illness, but often requires admission due to illness severity
  • Poor prognostic sign when MAT develops during hospitalization or acute illness
    • 60% in-hospital mortality
      • Due to illness, not arrhythmia
    • Mean survival around 1 year

See Also

External Links

References