Impact of impedance cardiography on diagnosis and therapy of emergent dyspnea: the ED-IMPACT trial

Acad Emerg Med. 2006 Apr;13(4):365-71. doi: 10.1197/j.aem.2005.11.078. Epub 2006 Mar 10.


Background: Dyspnea is one of the most common emergency department (ED) symptoms, but early diagnosis and treatment are challenging because of multiple potential causes. Impedance cardiography (ICG) is a noninvasive method to measure hemodynamics that may assist in early ED decision making.

Objectives: To determine the rate of change in working diagnosis and initial treatment plan by adding ICG data during the course of ED clinical evaluation of elder patients presenting with dyspnea.

Methods: The authors studied a convenience sample of dyspneic patients 65 years and older who were presenting to the EDs of two urban academic centers. The attending emergency physician was initially blinded to the ICG data, which was collected by research staff not involved in patient care. At initial ED presentation, after history and physical but before central lab or radiograph data were returned, the attending ED physician completed a case report form documenting diagnosis and treatment plan. The physician then was shown the ICG data and the same information was again recorded. Pre- and post-ICG differences were analyzed.

Results: Eighty-nine patients were enrolled, with a mean age of 74.8 +/- 7.0 years; 52 (58%) were African American, 42 (47%) were male. Congestive heart failure and chronic obstructive pulmonary disease were the most common final diagnoses, occurring in 43 (48%), and 20 (22%), respectively. ICG data changed the working diagnosis in 12 (13%; 95% CI = 7% to 22%) and medications administered in 35 (39%; 95% CI = 29% to 50%).

Conclusions: Impedance cardiography data result in significant changes in ED physician diagnosis and therapeutic plan during the evaluation of dyspneic patients 65 years and older.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Cardiography, Impedance* / methods
  • Diagnosis, Differential
  • Dyspnea / etiology*
  • Electrocardiography
  • Emergency Medicine
  • Emergency Service, Hospital
  • Female
  • Heart Failure / complications
  • Heart Failure / diagnosis*
  • Hemodynamics
  • Humans
  • Male
  • Prospective Studies
  • Pulmonary Disease, Chronic Obstructive / complications
  • Pulmonary Disease, Chronic Obstructive / diagnosis*
  • Radiography, Thoracic