Impedance Cardiography for Cardiac Output Estimation
نویسندگان
چکیده
everal studies suggest the importance of cardiac power output calculation, which is derived from cardiac output (CO) and mean blood pressure, to predict the prognosis in heart failure patients not only in hospital but also in the outpatient setting.1–3 CO measured by the thermodilution method with a Swan-Ganz catheter placed in the pulmonary artery has become one of the most widely accepted and used methods of monitor cardiac function, despite its certain limitations. 1,3,4 A noninvasive and low cost method for measuring CO would be relevant for the widespread clinical use of cardiac power output. Some noninvasive techniques of measuring CO have been proposed over the past years. The indirect Fick method of re-breathing carbon dioxide5,6 and Doppler flow measurement of the left ventricular outflow tract have been shown to be accurate;7 however, their applications require expensive equipments and trained operators. Other promising results have been observed with devices based on electrical bioimpedance technology,8 and 2 basic technologies of impedance cardiography (ICG) are currently in use. The first is called whole-body ICG9,10 (ICGWB), which was introduced in 1948,11 in which the electrodes are placed on the distal portion of the limbs. The second one is thoracic ICG (ICGT), which was introduced in 1964, and the electrodes are placed on the root of the neck and on the lower chest. When the CO is measured in subjects with healthy hearts, the results from both these technologies are usually reliable, but the reliability of CO measurements taken by ICGT is compromised in patients with cardiac diseases.12–16 According to the Food and Drug Administration (FDA) standard of bio-equivalence,17 the disparity between 2 techCirc J 2006; 70: 1164–1168
منابع مشابه
Automated non-invasive measurement of cardiac output: comparison of electrical bioimpedance and carbon dioxide rebreathing techniques.
Two commercial automated, non-invasive systems for estimation of cardiac output were evaluated. Values of cardiac output obtained by electrical bioimpedance cardiography (BoMed NCCOM3 machine) were compared with values derived from an indirect Fick technique that uses carbon dioxide rebreathing (Gould 9000 IV system) during 103 simultaneous measurements made at rest in 19 randomly selected subj...
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