Sick sinus syndrome

Background

  • Collection of signs or symptoms that indicate sinus node dysfunction[1]
  • May present as bradycardia, tachycardia, or alternating bradycardia and tachycardia
    • 50% have alternating bradycardia and tachycardia

Causes

  • Intrinsic:
    • Degenerative fibrosis
    • Infiltrative disease process
    • Ion channel dysfunction
    • SA node remodeling
  • Extrinsic:
    • Pharmacologic
    • Metabolic/electrolyte disturbance
    • Autonomic dysfunction
    • Obstructive sleep apnea

Clinical Features

  • Syncope or pre-syncope (50%)
  • Palpitations
  • Fatigue
  • Generalized weakness
  • Dyspnea
  • Angina
  • Disturbed sleep
  • Confusion

Differential Diagnosis

Symptomatic bradycardia

Evaluation

  • ECG identification, inpatient telemetry, outpatient Holter monitoring, event monitoring, loop monitoring
    • ECG frequently negative for findings early in disease course

Management

  • remove extrinsic factors and/or pacemakers
    • Pacemakers do not reduce mortality, only decrease symptoms

Disposition

  • Admit

Complications

  • (50%) Tachy-brady syndrome with atrial fibrillation or atrial flutter
  • (50%) AV block

See Also

External Links

References

  1. Semelka, M et Al. Sick Sinus Syndrome: A Review. Am Fam Physician. 2013 May 15;87(10):691-696. http://www.aafp.org/afp/2013/0515/p691.html