Overview

• Sinus arrest is the temporary interruption of sinoatrial node automaticity, that may occur due to intrinsic or extrinsic factors affecting the sinoatrial node.

• • Look For

  • A pause of at least three seconds, without P waves or QRS complexes
  • An escape rhythm may be present
• •  

• • Causes of Sinus Arrest

  • Intrinsic

  • Idiopathic degeneration
  • Myocardial infarction
  • Infiltrative disease - sarcoidosis, amyloidosis, haemochromatosis
  • Connective tissue disease - SLE, scleroderma, RA
  • Cardiac surgery - valvular surgery, correction of congenital heart disease
  • Infections - Lyme disease, endocarditis

  • Extrinsic

  • Physiologic - sleep, athletes
  • Autonomic - neurocardiogenic syncope, carotid sinus hypersensitivity
  • Drugs - beta blockers, calcium channel blockers, digoxin, adenosine, ivabradine, clonidine, acetylcholinesterase inhibitors
  • Hypothyroidism
  • Hypothermia
  • Hyperkalaemia
  • Obstructive sleep apnoea
  • Raised intracranial pressure