title: Fourier analysis on ungated time-activity curves.
abstract: The frequency content of the ungated radionuclide time-activity curves for left and right ventricles was analyzed using a power spectrum estimation technique. This technique was applied to ten patients. It was observed that 75% of the contraction power of any ventricle was contained in the fundamental and at least 98% contained in the fundamental plus the first harmonic. Patients presenting bigeminy and trigeminy had a completely different spectrum distribution which calls for a different interpretation. Low frequency spectrum lines have been observed at breathing frequency. Up to 62% of the total power may be contained in those spectrum lines.
mesh_terms: D004912:Erythrocytes; D005583:Fourier Analysis; D006321:Heart / Q000000981:diagnostic imaging*; D006339:Heart Rate; D006801:Humans; D009200:Myocardial Contraction; D011877:Radionuclide Imaging; D013318:Stroke Volume; D013667:Technetium; D013997:Time Factors
chemical_list: D013667:Technetium