- Title
- Accuracy of continuous non-invasive impedance cardiographic measurements of stroke volume in exercising man
- Creator
- White, Saxon William; Letchford, P. J.; Traugott, F. M.; Brown, W. J.; Porges, W. L.; Quail, A. W.
- Relation
- 7th Commonwealth and International Conference on Sport, Physical Education, Recreation and Dance (Conference '82). Proceedings of the 7th Commonwealth and International Conference on Sport, Physical Education, Recreation and Dance, Volume 8 (Gold Coast, Qld 27-29 September, 1982) p. 119-128
- Publisher
- Dept. of Human Movement Studies, University of Queensland
- Resource Type
- conference paper
- Date
- 1983
- Description
- Several new techniques have been introduced and/or refined over the past decade for the non-invasive measurement of stroke volume (SV) and cardiac output (CO) in man which have clear implications for the assessment of performance characteristics of athletes hitherto not possible. The CO2 rebreathing method, however, still suffers from relatively poor accuracy at rest, and gated pool radionuclide scanning requires high levels of medical technological expertise under confined laboratory conditions. Impedance cardiography (IC) does not suffer from these disadvantages. We have evaluated the accuracy of impedance cardiography against accepted invasive methods e.g. thermodilution (TD), dye dilution (DD), the electromagnetic flowmeter (EM), in models where different degrees of experimental control could be applied. This approach was necessary due to the empirical aspects of the Kubicek formula for the calculation of stroke volume using IC. In addition, we have assessed the accuracy of the independent methods in clinical usage, as the assessment of accuracy of impedance cardiography would depend to some extent on the accuracy of the independent method used. Using regression analysis of simultaneous estimates of SV and CO, the accuracy of TD (against EM) in rabbits is 1.0% (S.E. of a single CO estimate expressed as % of mean CO (492 ± 3.5 ml), and that of IC SV measurements in the dog (against EM) is 1.7% (22.2 ± 0.4ml). In man, the accuracy of right heart thermodilution SV measurements (against DD) is 3.9% (75.4 3.0ml), and that for IC SV measurements (against TD) is 2.1 % (58.2 ± 1.2ml). These results indicate that both the invasive TD, and the non-invasive IC systems used in our laboratories have comparable and satisfactory accuracies for SV measurement, and suggest that under conditions of normal hearts and lungs, IC is useful for accurate and continuous non-invasive stroke volume measurements in exercising man, provided certain conditions of usage are satisfied.
- Subject
- cardiographic measurements; stroke; exercise; men
- Identifier
- http://hdl.handle.net/1959.13/938895
- Identifier
- uon:12691
- Identifier
- ISBN:0867761318
- Language
- eng
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