The incidence of pulmonary embolism in unexplained sudden cardiac arrest with pulseless electrical activity

Am J Med. 2000 Oct 1;109(5):351-6. doi: 10.1016/s0002-9343(00)00511-8.


Purpose: The cause of many cases of sudden cardiac arrest from pulseless electrical activity is unknown. We hypothesized that pulmonary embolism was responsible for a substantial proportion of these cases and used transesophageal echocardiography to identify pulmonary embolism among patients with sudden cardiac arrest.

Subjects and methods: We performed a prospective study at a tertiary care, university-operated county hospital, with a level 1 trauma center. Consecutive patients (n = 36) who were admitted with (n = 20) or unexpectedly developed (n = 16) sudden cardiac arrest of unknown cause were studied with transesophageal echocardiography during cardiopulmonary resuscitation. We determined the presence of central pulmonary embolism, right ventricular enlargement, and other causes of sudden cardiac arrest (such as myocardial infarction and aortic dissection) using prospectively defined criteria.

Results: Of the 25 patients with pulseless electrical activity as the initial event, 9 (36%) had pulmonary emboli (8 seen with transesophageal echocardiography and 1 diagnosed at autopsy) compared with none of the 11 patients with other rhythms, such as asystole or ventricular tachycardia or fibrillation (P = 0.02). Of the 8 patients who had pulmonary embolism diagnosed by transesophageal echocardiography, 2 survived to hospital discharge.

Conclusions: Mortality from massive pulmonary embolism is high, particularly if patients present with sudden cardiac arrest. Earlier diagnosis of pulmonary embolus may permit wider use of thrombolytic agents or other interventions and may potentially increase survival.

MeSH terms

  • Aged
  • Cardiopulmonary Resuscitation
  • Diagnosis, Differential
  • Echocardiography, Transesophageal*
  • Electrocardiography
  • Female
  • Heart Arrest / diagnostic imaging*
  • Heart Arrest / etiology*
  • Heart Arrest / therapy
  • Hospitals, University
  • Humans
  • Incidence
  • Male
  • Middle Aged
  • Northwestern United States / epidemiology
  • Prospective Studies
  • Pulmonary Embolism / complications*
  • Pulmonary Embolism / diagnostic imaging
  • Pulmonary Embolism / epidemiology*
  • Pulmonary Embolism / mortality
  • Pulse