ISSN:
1619-7089
Keywords:
Fourier analysis
;
Cardiac phantom model
;
Artificial heart
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract Using pusher-plate-type artificial hearts, changes in the degree of synchrony and stroke volume were compared to phase and amplitude calculations from the first Fourier component of individual-pixel time-activity curves generated from gated radionuclide images (RNA) of these hearts. In addition, the ability of Fourier analysis to quantify paradoxical volume shifts was tested using a ventricular aneurysm model by which the Fourier amplitude was correlated to known increments of paradoxical volume. Predetermined phase-angle differences (incremental increases in asynchrony) and the mean phase-angle difference calculated from RNAs showed an agreement of -7°±4.4° (mean ±SD). A strong correlation was noted between stroke volume and Fourier amplitude (r=0.98; P〈0.0001) as well as between the paradoxical volume accepted by the ‘aneurysm’ and the Fourier amplitude (r=0.97; P〈0.0001). The degree of asynchrony and changes in stroke volume were accurately reflected by the Fourier phase and amplitude values, respectively. In the specific case of ventricular aneurysms, the data demonstrate that using this method, the paradoxically moving areas may be localized, and the expansile volume within these regions can be quantified.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00261400
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