Modelflow estimates of cardiac output compared with Doppler ultrasound during acute changes in vascular resistance in women

Autor: J. Kevin Shoemaker, Kenneth S. Dyson, Philippe Arbeille, Richard L. Hughson
Rok vydání: 2010
Předmět:
Zdroj: Experimental Physiology. 95:561-568
ISSN: 0958-0670
DOI: 10.1113/expphysiol.2009.050815
Popis: We compared Modelflow (MF) estimates of cardiac stroke volume (SV) from the finger pressure-pulse waveform (Finometer®) with pulsed Doppler ultrasound (DU) of the ascending aorta during acute changes in total peripheral resistance (TPR) in the supine and head-up-tilt (HUT) postures. Twenty-four women were tested during intravenous infusion of 0.005 or 0.01 μg kg−1 min−1 isoprenaline, 10 or 50 ng kg−1 min−1 noradrenaline and 0.3 mg sublingual nitroglycerine. Responses to static hand-grip exercise (SHG), graded lower body negative pressure (LBNP, from −20 to −45 mmHg) and 45 deg HUT were evaluated on separate days. Bland–Altman analysis indicated that SVMF yielded lower estimates than SVDU during infusion of 0.01 μg kg−1 min−1 isoprenaline (SVMF 92.7 ± 15.5 versus SVDU 104.3 ± 22.9 ml, P= 0.03) and SHG (SVMF 78.8 ± 12.0 versus SVDU 106.1 ± 28.5 ml, P < 0.01), while larger estimates were recorded with SVMF during −45 mmHg LBNP (SVMF 52.6 ± 10.7 versus SVDU 46.2 ± 14.5 ml, P= 0.04) and HUT (SVMF 59.3 ± 13.6 versus SVDU 45.2 ± 11.3 ml, P < 0.01). Linear regression analysis revealed a relationship (r2= 0.41, P < 0.01) between the change in TPR from baseline and the between-methods discrepancy in SV measurements. This relationship held up under all of the experimental protocols (regression for fixed effects, P= 0.46). These results revealed a discrepancy in MF estimates of SV, in comparison with those measured by DU, during acute changes in TPR.
Databáze: OpenAIRE
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