Vagal syncope during recurrent pulmonary embolism

JAMA. 1983 Jan 21;249(3):390-3.


The mechanism for syncope during pulmonary embolism is not well understood. We describe two patients with transient sinus bradycardia and atrioventricular (AV) block during syncope from recurrent pulmonary embolism. Consciousness was regained each time the rhythm returned to normal. We believe that the syncope and bradyarrhythmia was caused by a parasympathetic reflex, since simultaneous slowing of the sinus rate with concomitant AV block is a common manifestation of increased vagal tone. Such a reflex is consistent with known cardiac reflexes, may occur frequently, and may be one of the mechanisms for syncope in patients with pulmonary embolism.

Publication types

  • Case Reports
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Bradycardia / etiology
  • Electrocardiography
  • Female
  • Heart Block / etiology
  • Humans
  • Male
  • Middle Aged
  • Pulmonary Embolism / complications*
  • Recurrence
  • Syncope / etiology*
  • Syncope / physiopathology
  • Vagus Nerve / physiopathology*