PMID: 9435597Jan 22, 1998Paper

Left atrial distension and antiorthostatic decrease in arterial pressure and heart rate in humans

The American Journal of Physiology
B PumpP Norsk

Abstract

It was investigated to what degree left atrial distension augments the hypotensive effects of a 15-min moderate antiorthostatic maneuver in humans. Ten healthy males underwent a posture change from upright seated (Seat, legs horizontal) to supine (Sup) or to supine with simultaneous lower body negative pressure (Sup + LBNP) to keep left atrial diameter (LAD) unchanged. After 2.5 min of Sup, mean arterial pressure (MAP) decreased from 94 +/- 3 to 86 +/- 3 mmHg (P < 0.05), whereas a similar decrease was delayed 7.5 min into Sup + LBNP. Heart rate (HR) decreased within 2.5 min of Sup from 68 +/- 2 to 60 +/- 3 beats/min (P < 0.05) and remained significantly decreased for at least 2.5 min longer than during Sup + LBNP. Aortic systolic distension (ASD) increased by 59 +/- 17% during Sup (P < 0.05) but was unchanged during Sup + LBNP. The 29 +/- 4% decrease in plasma norepinephrine (NE) during Sup (P < 0.05) was abolished during Sup + LBNP. In conclusion, the increases in LAD and ASD seem important stimuli for the prompt decrease in MAP, the 2.5-min longer-lasting decrease in HR, and the sustained decrease in NE during a 15-min moderate antiorthostatic posture change in humans.

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Citations

Feb 18, 2012·American Journal of Physiology. Regulatory, Integrative and Comparative Physiology·Sine K ArvedsenPeter Norsk
May 18, 2001·American Journal of Physiology. Heart and Circulatory Physiology·B PumpP Norsk
Aug 22, 2001·American Journal of Physiology. Heart and Circulatory Physiology·B PumpP Norsk
Dec 13, 2018·Physiological Reviews·Nandu GoswamiVictor A Convertino
Dec 18, 2001·Journal of Applied Physiology·Makoto ShiraishiPeter Norsk
Dec 12, 2018·American Journal of Physiology. Heart and Circulatory Physiology·Jian CuiLawrence I Sinoway
Apr 8, 2006·Journal of Applied Physiology·A Cortney HendersonG Kim Prisk
Aug 21, 2015·American Journal of Physiology. Regulatory, Integrative and Comparative Physiology·Sine Kongsbak ArvedsenMorten Damgaard
Jul 6, 2021·Heart Rhythm O2·María Mónica Marín ODavid Santacruz P

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