Impact of Obesity on Noninvasive Cardiac Hemodynamic Measurement by Electrical Cardiometry in Adults With Aortic Stenosis

J Cardiothorac Vasc Anesth. 2018 Dec;32(6):2505-2511. doi: 10.1053/j.jvca.2018.04.040. Epub 2018 Apr 26.


Objectives: There are substantial potential benefits to noninvasive cardiac monitoring methods, such as electrical cardiometry (EC), over more invasive methods, including significantly reduced risk of complications, lower up-front and operational costs, ease of use, and continuous monitoring. To take advantage of these technologies, clinical equivalence to currently established methods must be determined. The authors sought to determine if the noninvasive measurement of cardiac index (CI) by EC was clinically equivalent to thermodilution (TD) in adult patients with aortic stenosis (AS).

Design: This is a cross-sectional study comparing measurement devices in a single patient group.

Setting: Single-center, university teaching hospital.

Participants: The study included 52 adult patients with aortic stenosis undergoing right heart catheterization.

Interventions: Cardiac output (CO) was measured concurrently using EC with an ICON device and TD in 52 participants with AS. CI values were to determine the accuracy and precision of EC in reference to TD. Percentage error (PE) was used to assess their clinical equivalence. The participants were divided further into groups (normal and overweight/obese) based on body mass index and the analysis was repeated.

Measurements and main results: CO measurement made by EC in adult patients with obesity or overweight was reduced significantly relative to TD. This was not observed in normal-weight adult AS patients. EC provided clinically equivalent measurements to TD for measuring CI in normal-weight adult AS patients (PE = 25.0%), but not for those adult AS patients with overweight or obesity (PE = 42.3%).

Conclusion: Overall, the ICON device produced lower CO and index measurements relative to TD in adult patients with AS. Overweight and obesity also significantly affected the relative precision and accuracy of the ICON electrical cardiometric device to measure CI in these patients.

Keywords: aortic valve stenosis; bioimpedance; cardiac output; electrical cardiometry; obesity; thermodilution.

MeSH terms

  • Aged
  • Aortic Valve Stenosis / complications
  • Aortic Valve Stenosis / diagnosis
  • Aortic Valve Stenosis / physiopathology*
  • Blood Flow Velocity / physiology
  • Cardiac Catheterization / methods*
  • Cardiac Output / physiology
  • Cross-Sectional Studies
  • Electric Impedance
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Obesity / complications*
  • Obesity / physiopathology
  • Reproducibility of Results
  • Retrospective Studies
  • Systole
  • Thermodilution / methods