title: Interference of cardiovascular sounds with phonopneumography in children.
abstract: We have used fast Fourier transform and power spectra analysis to determine possible interference of cardiovascular sounds with the analysis of breath sounds in children. Ten normal children, 8 to 13 yr of age, were studied with sound transducer over midprecordium, right upper lobe, and right lower lobe along with simultaneously recorded ECG and air flow. Detection of R-waves facilitated sampling of sound segments at defined flow rates, with inclusion or exclusion of heart sounds. Measurements during breath-holding and without heart sounds served as baseline values. Heart sounds were only slightly attenuated over the right upper lobe. There was a considerable overlap in the power spectra of heart and breath sounds, mainly in frequencies below 100 Hz. Analysis of low-frequency components of normal breath sounds requires sampling during parts of the cardiac cycle that are free of cardiovascular sounds.
mesh_terms: D000293:Adolescent; D001314:Auscultation / Q000592:standards*; D002320:Cardiovascular Physiological Phenomena; D002648:Child; D005260:Female; D006326:Heart Auscultation; D006347:Heart Sounds; D006801:Humans; D008297:Male; D012135:Respiratory Sounds