title: Estimating stroke volume from oxygen pulse during exercise.
abstract: This investigation aimed at verifying whether it was possible to reliably assess stroke volume (SV) during exercise from oxygen pulse (OP) and from a model of arterio-venous oxygen difference (a-vO(2)D) estimation. The model was tested in 15 amateur male cyclists performing an exercise test on a cycle-ergometer consisting of a linear increase of workload up to exhaustion. Starting from the analysis of previous published data, we constructed a model of a-vO(2)D estimation (a-vO(2)D(est)) which predicted that the a-vO(2)D at rest was 30% of the total arterial O(2) content (CaO(2)) and that it increased linearly during exercise reaching a value of 80% of CaO(2) at the peak workload (W(max)) of cycle exercise. Then, the SV was calculated by applying the following equation, SV = OP/a-vO(2)D(est), where the OP was assessed as the oxygen uptake/heart rate. Data calculated by our model were compared with those obtained by impedance cardiography. The main result was that the limits of agreement between the SV assessed by impedance cardiography and the SV estimated were between 22.4 and -27.9 ml (+18.8 and -24% in terms of per cent difference between the two SV measures). It was concluded that our model for estimating SV during effort may be reasonably applicable, at least in a healthy population.
authors: Department of Science Applied to Biological Systems, Section of Human Physiology, University of Cagliari, Italy. crisafulli@tiscali.it
authors: Antonio
authors: A
authors: Crisafulli
authors: Francesco
authors: F
authors: Piras
authors: Paolo
authors: P
authors: Chiappori
authors: Stefano
authors: S
authors: Vitelli
authors: Marcello A
authors: MA
authors: Caria
authors: Andrea
authors: A
authors: Lobina
authors: Raffaele
authors: R
authors: Milia
authors: Filippo
authors: F
authors: Tocco
authors: Alberto
authors: A
authors: Concu
authors: Franco
authors: F
authors: Melis
mesh_terms: D000328:Adult; D002307:Cardiography, Impedance; D017097:Electric Impedance; D015444:Exercise / Q000502:physiology*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D010100:Oxygen / Q000378:metabolism*; D013318:Stroke Volume / Q000502:physiology*; D013997:Time Factors
chemical_list: D010100:Oxygen