Wandering atrial pacemaker

Background

• Three or more ectopic foci within the atrial myocardium serve as the pacemaker
• Rate is less than 100bpm (in contrast to MAT)
• Is irregularly irregular therefore sometimes confused with atrial fibrillation and sinus arrhythmia

Causes

• Intrinsic cardiac or pulmonary disease
• Metabolic derangements
• Drug toxicity (including Digoxin)

Clinical Features

• Often seen in the extremes of age and in athletes
• Rarely causes symptoms

Differential Diagnosis

Palpitations

• Arrhythmias:
  • Narrow-complex tachycardias
  • Wide-complex tachycardias
  • AV blocks
    • Second Degree AV Block Type I (Wenckeback)
    • Second Degree AV Block Type II
    • Third Degree AV Block
  • Premature atrial contraction
  • Premature junctional contraction
  • Premature ventricular contraction
  • Sick sinus syndrome
  • Wandering atrial pacemaker
• Non-arrhythmic cardiac causes:
  • Acute coronary syndrome
  • Cardiomyopathy
  • Congenital heart disease
  • Congestive heart failure (CHF)
  • Mitral valve prolapse
  • Pacemaker complication
  • Pericarditis
  • Myocarditis
  • Valvular disease
• Psychiatric causes:
  • Panic attack
  • Anxiety
  • Somatic Symptom Disorder
• Drugs and Medications:
  • Alcohol
  • Caffeine
  • Drugs of abuse (e.g. cocaine)
  • Medications (e.g. digoxin, theophylline)
  • Tobacco
• Misc
  • Anemia
  • Hyperthyroidism
    • Thyroid storm
  • Pulmonary embolism
  • Dehydration
  • Sepsis
  • Pheochromocytoma

Evaluation

Workup

• ECG

Diagnosis

• ECG should show three distinct P wave morphologies with a ventricular rate <100bpm

Management

• Rarely requires treatment

Disposition

• Outpatient management

See Also

• Multifocal atrial tachycardia
• Dysrhythmia
• ECG (main)