Determination of Cardiac Output in Pulmonary Hypertension Using Impedance Cardiography

Area of Science:

• Cardiology
• Medical Devices
• Pulmonary Hypertension Research

Background:

• Cardiac output (CO) is a critical prognostic indicator in pulmonary hypertension (PH).
• Right heart catheterization (RHC) via direct Fick or thermodilution (TD) are gold standards for CO measurement.
• Impedance cardiography (IPc) offers a non-invasive alternative for CO assessment.

Purpose of the Study:

• To evaluate the accuracy of the PHYSIOFLOW® system for CO measurement in PH patients.
• To compare IPc-derived CO with reference methods (Fick and TD) in specific PH groups (1 and 4).

Main Methods:

• Prospective study involving 75 PH patients at a reference center.
• Simultaneous CO measurements using Fick, TD, and IPc during RHC.
• Bland-Altman analysis to assess agreement between CO measurement techniques.

Main Results:

• Mean CO values were similar across Fick (5.7±1.9 L/min), TD (5.4±1.5 L/min), and IPc (5.5±1.7 L/min).
• Low bias observed between IPc and Fick (0.149 L/min) and IPc and TD (-0.153 L/min).
• Correlation diminished at extreme CO levels (<3 L/min or >7 L/min); BMI and PH group influenced agreement.

Conclusions:

• IPc measurement of CO in PH patients demonstrates reliability comparable to direct Fick and TD methods.
• The accuracy of IPc for CO assessment may be reduced in cases of extreme cardiac output values.