title: [Doppler sonography determination of flow ratios Qp/Qs and resistance ratios Rp/Rs in isolated ventricular septal defect].
abstract: We present a model based on an electric analogon that describes the haemodynamic situation of an isolated ventricular septal defect. The model shows a way to estimate the ratio of pulmonary to systemic vascular resistance by Doppler sonographic measurements of pulmonary to systemic flow ratio (Qp/Qs) and the ratio between the size of the defect and the cross-sectional area of the aorta (Av/Aa). The ratio of pulmonary to systemic vascular resistance is theoretically given by: Rp/Rs = Qs/Qp + log (Av/Aa) * (1-Qs/Qp). Systemic to pulmonary flow ratio can be measured by Doppler echocardiography as well as Av/Aa; therefore, Rp/Rs can be estimated noninvasively by the equation given above. The values estimated noninvasively by Doppler echocardiography showed a good correlation with the haemodynamic data obtained at cardiac catheterisation.
authors.affiliation: Kardiologische Abteilung, Universitäts-Kinderklinik Erlangen.
authors.forename: T
authors.initials: T
authors.lastname: Rupprecht
authors.forename: K H
authors.initials: KH
authors.lastname: Deeg
authors.forename: M
authors.initials: M
authors.lastname: Hofbeck
authors.forename: K
authors.initials: K
authors.lastname: Richter
authors.forename: H
authors.initials: H
authors.lastname: Singer
mesh_terms: D001013:Aorta, Thoracic / Q000473:pathology; D001783:Blood Flow Velocity; D006328:Cardiac Catheterization; D003198:Computer Simulation; D015150:Echocardiography, Doppler / Q000379:methods*; D006345:Heart Septal Defects, Ventricular / Q000151:congenital* / Q000175:diagnosis; D006439:Hemodynamics; D006801:Humans; D007223:Infant; D008955:Models, Cardiovascular; D011651:Pulmonary Artery / Q000473:pathology; D014655:Vascular Resistance
vernacular_title: Dopplersonographische Bestimmung von Flussverhältnis Qp/Qs und Widerstandsverhältnis Rp/Rs beim isolierten Ventrikelseptumdefekt.