Related Experiment Video
Updated: Apr 23, 2026

Cutoff Value of Phase Angle by Bioelectrical Impedance Analysis at Admission as a Prognostic Factor in Patients with Acute Heart Failure
Published on: June 10, 2025
Correlation between trans and intra-thoracic impedance and conductance in patients with chronic heart failure
Gabriella Malfatto1, Alessandra Villani, Francesco Della Rosa
1aDivisione di Cardiologia, Ospedale San Luca, Istituto Auxologico Italiano IRCCS bDipartimento di Medicina Clinica, Prevenzione e Biotecnologie Sanitarie, Università di Milano-Bicocca, Milan, Italy.
Aims:
In chronic heart failure, changes of intra-thoracic impedance (Z0IT) may suggest impending pulmonary congestion; a similar result has been found by measuring trans-thoracic conductance (TFCTT = 1/Z0 = 1/kΩ). We assumed that a relationship could exist between Z0IT and TFCTT.
Methods:
We collected 140 measurements from 70 patients carrying an implantable cardioverter-defibrillator/cardiac resynchronization device with the CareLink function (71 ± 9 years, New York Heart Association (NYHA) 2.4 ± 0.9, ejection fraction 31 ± 8%, optimal treatment); they were studied during system alarms and after appropriate treatment (diuretics and/or vasodilators, n = 42) or during clinical stability and at the time of a system alarm (n = 28); correspondent BNP values were obtained. We related Z0IT obtained by the device, with TFCTT obtained with a commercial system.
Results:
A strong relationship was found between Z0IT and TFCTT. Changes in the variables after treatment or during worsening conditions were of the same direction and order of magnitude, and were related to BNP levels obtained simultaneously.
Conclusions:
Trans-thoracic conductance, similarly to intra-thoracic impedance, may noninvasively point to pulmonary congestion and be useful in patients not carrying an implanted device. The possibility of remotely obtaining this variable should be evaluated for the telemonitoring of heart failure patients.
More Related Videos
04:05Author Spotlight: Unveiling Prognostic Indicators in Heart Failure - The Role of Phase Angle and Bioelectrical Impedance Analysis
Published on: June 30, 2023
10:21Evaluation of Hydration Status by Bioelectrical Impedance Vector Analysis in Patients with Ischemic Heart Disease Undergoing Exercise Stress Test
Published on: September 22, 2023
Related Concept Videos
Bode Plots Construction
Heart Failure II: Pathophysiology
Heart Failure III: Clinical Manifestations
Aortic Regurgitation II: Clinical Features and Diagnostic Tests
Resistance and Conductance
Various factors impact the resistance of a conductor. Spiraling in stranded conductors increases their...
Heart Failure I: Introduction