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

• COPD
• CHF
• Sepsis
• Methylxanthine toxicity
• Electrolyte abnormalities
• Other associations
  • Valvular heart disease
  • DM
  • Acute renal failure
  • Postoperative state
  • Pulmonary embolism
  • Pneumonia
  • Anemia

Clinical Features

• Palpitations
• Dyspnea
• Chest pain
• Presyncope/syncope

Multifocal atrial tachycardia

Differential Diagnosis

Palpitations

• Arrhythmias:
  • Atrial fibrillation
  • Grouped beats on ECG (commonly misdx as A-fib)
    • Atrial bigeminy and trigeminy
    • Mobitz I or Mobitz II
  • Atrial flutter
  • SVT
  • Ventricular Tachycardia
  • Sick sinus syndrome
  • Multifocal atrial tachycardia
  • PVCs
  • Wolff–Parkinson–White syndrome (WPW)
  • Sinus node dysfunction
  • AV Block
  • Lown-Ganong-Levine Syndrome‎
  • Accelerated idioventricular rhythm
• Non-arrhythmic cardiac causes:
  • Cardiomyopathy
  • CHF
  • Mitral valve prolapse
  • Congenital heart disease
  • Pericarditis
  • Valvular disease
  • Pacemaker malfunction
  • Acute MI
• Psychiatric causes:
  • Anxiety disorder
  • Panic attack
• Drugs and Medications:
  • Alcohol
  • Caffeine
  • Meds (i.e. digitalis, theophylline)
  • Street drugs (i.e. cocaine)
  • Tobacco
• Misc
  • Hyperthyroidism

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 the 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 BB/CCB in hemodynamically stable patient (caution with pulmonary disease)
• Cardioversion not definitive, likely recurrence if underlying illness not addressed

Disposition

• Disposition depends on the underlying illness, but often requires admission due to illness severity/age
• Poor prognostic sign when developed during hospitalization/illness
  • 60% in hospital mortality
  • mean survival around 1 year
  • Due to illness not arrhythmia

References

Authors

Colin Hoff, Kevin Lu, Ross Donaldson, Neil Young, Claire, Daniel Ostermayer