Utility of Impedance Cardiography to Determine Cardiac vs. Noncardiac Cause of Dyspnea in the Emergency Department

Abstract

Determining the correct diagnosis of patients with dyspnea can be challenging. Early and accurate determination of the cause of dyspnea is vital in instituting timely and appropriate interventions. Hemodynamic parameters may aid in the evaluation of dyspnea, but are difficult to assess by physical exam. Impedance cardiography (ICG) is a newly validated method of determining hemodynamic parameters noninvasively. The purpose of this study was to determine the accuracy in differentiating cardiac from noncardiac causes of dyspnea utilizing ICG-derived hemodynamic parameters compared with that of emergency department (ED) physicians after initial history, physical, and laboratory tests. The final diagnosis, which was made retrospectively after review of the patient's hospital record by a senior ED physician blinded to the ICG data, was compared with the treating ED physician's and the ICG diagnoses. Thirty-eight patients who presented with dyspnea to a community ED were included in the study. There were significant differences in values of cardiac index by ICG (2.2 vs. 3.1; p<0.0001), systolic time ratio (0.52 vs. 0.37; p<0.01) and velocity index (32.9 vs. 42.7; p<0.01) between the cardiac and noncardiac groups, respectively. ICG measurements demonstrated greater sensitivity (92 vs. 83%), specificity (88 vs. 77%), and positive and negative predictive values (79 vs. 63% and 96 vs. 91%, respectively) compared with the ED physician in distinguishing cardiac from noncardiac cause of dyspnea. ICG can aid ED physicians in making more rapid and accurate determinations of cardiac vs. noncardiac cause of dyspnea.

The Herbal Medicine Daikenchuto Increases Blood Flow in the Superior Mesenteric Artery

“…There were no significant changes in any index. .9) 171.9 (9.4) 169.9 (9.0) 175.6 (9.8) 95% CI 153.7,189.4 155.2,183.8 153.8,188.4 153.4,188.0 146.4,183.3 152.9,194.5 155.1,190.1 153.5,190.3 152.3,187.5 156.3,194.9 Daikenchuto + Water Mean (SEM) 165.6 (10.2) 172.6 (10.1) 182.5 (11.3)* 185.2 (11.5)** 188.5 (11.6)** 186.7 (13.2)* 189.7 (13.4)** 189.8 (13.7)** 186.8 (12.9)** 178.3 (11.3) 95% CI 145.6,185.5 152.9,192.3 160.4,204.6 162.8,207.7 165.7,211. culate hemodynamic parameters such as stroke volume, CO, and cardiac index (Springfield et al 2004). The latest-generation ICG device (BioZ ICG Module, Dash 3000 ® , GE Healthcare, Tokyo, Japan) provides highly reproducible and accurate data in a number of clinical settings, including assessment of heart failure (Strobeck and Silver 2004).…”

Bioimpedância transtorácica comparada à ressonância magnética na avaliação do débito cardíaco

“…TIC made physicians change patients' diagnosis in 13% of the cases, and medications in 39% of the patients 6 . In another study, it was useful to differentiate cardiac form noncardiac dyspnea 7 . However, these studies are limited by the lack of a control group and by nonrandomization, which makes it difficult to evaluate the ability of the method in changing outcomes.…”

“…The clinical application of TIC has been assessed in patients with acute dyspnea in the emergency department 6,7 . TIC made physicians change patients' diagnosis in 13% of the cases, and medications in 39% of the patients 6 .…”

“…Thus, hemodynamic parameters and the volemic status can be estimated. Although TIC has been evaluated in some clinical situations [6][7][8][9] , some questions remain on its accuracy and usefulness 10 . Cardiac magnetic resonance imaging (CMRI) is considered the gold-standard for the calculation of cardiac volumes 11,12 , and no previous study comparing the two methods has ever been conducted.…”

Bioelectrical impedance analysis for heart failure diagnosis in the ED

“…In another setting, Springfield et al [22] found that thoracic impedance had a sensitivity of 92 % and a sensitivity of 88% for the diagnosis of AHF. These results are not directly comparable to ours because thoracic impedance mainly studies cardiac output and aortic velocity.…”