Decrease in left ventricular ejection time on digital arterial waveform during simulated hypovolemia in normal humans.
BACKGROUND
Left ventricular ejection time (LVET) measured in central arteries is modified during hypovolemia. We compared modifications of the pulse wave in a central artery (carotid) and in a peripheral artery (digital) during central hypovolemia induced by lower body negative pressure (LBNP) in conscious volunteers.


METHODS
Hypovolemia was simulated with progressive LBNP (baseline, -10, -20, and -30 mm Hg) in nine young healthy volunteers. The carotid arterial pressure waveform was recorded using a Millar tonometric method. The digital pulse wave was measured with a volume-clamp method (Finapres) and the stroke volume with a thoracic impedance method (Biomed).


RESULTS
Mean arterial pressure did not change during LBNP. Compared with baseline values, heart rate increased significantly at the -30 mm Hg level (68 +/- 13 beats/min vs. 59 +/- 11 beats/min), and stroke volume decreased as soon as -10 mm Hg was achieved (113 +/- 41 mL vs. 127 +/- 35 mL). Both carotid and digital LVET decreased significantly at the -10 mm Hg level (337 +/- 26 and 339 +/- 24 ms vs. 360 +/- 35 and 361 +/- 24 ms, respectively).


CONCLUSIONS
Peripheral LVET could reflect variation of central LVET during LBNP and be a reliable noninvasive parameter for monitoring hypovolemia.
Geeraerts
Thomas
T
Department of Anesthesiology and UPRES 3540, Hôpital de Bicêtre, Le Kremlin Bicêtre, France.
Albaladejo
Pierre
P
Declère
Adrien Descorps
AD
Duranteau
Jacques
J
Sales
Jean-Patrick
JP
Benhamou
Dan
D
D000328:Adult; D001794:Blood Pressure; D002339:Carotid Arteries; D006801:Humans; D020896:Hypovolemia / Q000503:physiopathology*; D008297:Male; D013318:Stroke Volume; D013997:Time Factors