Application of impedance cardiography during exercise
| Autor: | M. H. Cox, D. S. Miles, Tony J. Verde, Robert W. Gotshall |
|---|---|
| Rok vydání: | 1993 |
| Předmět: |
Adult
Male Cardiac output medicine.medical_specialty Supine position Population Posture Myocardial Ischemia Physical exercise Cardiography Impedance Ventricular Function Left Internal medicine Medicine Humans Cardiac Output education End-systolic volume education.field_of_study medicine.diagnostic_test business.industry General Neuroscience Signal Processing Computer-Assisted Stroke volume Impedance cardiography Neuropsychology and Physiological Psychology Cardiology Exercise Test Female business Artifacts Software Computer technology |
| Zdroj: | Biological psychology. 36(1-2) |
| ISSN: | 0301-0511 |
| Popis: | Impedance cardiography has been used over the last 30 years to measure stroke volume on a beat-by-beat basis. Cardiac output has been successfully measured with either upper or lower body exercise during light or moderate workloads. With strenuous exercise, movement artifacts severely limit the acquisition of a quality impedance cardiogram. Advances in computer technology and signal conditioning techniques have created the next generation of impedance cardiograph systems. The purpose of this study was to evaluate such a system, the noninvasive continuous cardiac output monitor (NCCOM3-R7), at rest and during submaximal upright cycle exercise. In addition, the relationships between thoracic impedance (Z(o)), first derivative of the change in thoracic impedance (dZ/dt) and posture were evaluated using the NCCOM3-R7 and the Minnesota impedance cardiograph 304B (MIC). Twenty-eight healthy men and women participated. The Z(o) progressively increased when moving from the supine to seated to standing position with both instruments. However, the NCCOM3-R7 yielded lower Z(o) values and higher dZ/dt values compared with the MIC for all postures. Z(o) and dZ/dt values appear to be dependent upon factors such as posture, gender, electrical current, and characteristics of the instrumentation. Exercise cardiac output values seemed reasonable for most subjects, although population subsets exist where the accuracy must be questioned. The general consensus supported by the impedance literature and reaffirmed by the present observations is that impedance cardiography provides a reasonable estimate of the directional changes in stroke volume and cardiac output during exercise and can be used to monitor changes in thoracic fluid balance. As this technology evolves and is further refined, it will undoubtedly play an increasing role in environmental medicine, exercise stress testing, cardiac rehabilitation, and sports medicine. |
| Databáze: | OpenAIRE |
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