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Long‐Duration +Gz Acceleration on Cardiac Volumes Determined by Two‐Dimensional Echocardiography
Author(s) -
Tripp Lloyd D.,
Jennings Thomas J.,
Seaworth John F.,
Howell Lora L.,
Goodyear Chuck
Publication year - 1994
Publication title -
the journal of clinical pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.92
H-Index - 116
eISSN - 1552-4604
pISSN - 0091-2700
DOI - 10.1002/j.1552-4604.1994.tb04991.x
Subject(s) - acceleration , cardiology , duration (music) , medicine , diastole , physics , blood pressure , classical mechanics , acoustics
To enhance protection of humans exposed to long‐duration low‐gravity environments such as the Space Shuttle and National Aerospace Plane during re‐entry or in the short‐duration high‐+Gz environment of fighter aircraft, the effects of +Gz acceleration on cardiovascular hemodynamics must be understood. This study reports the use of two‐dimensional echocardiography in normal men during +Gz acceleration. The heart's position in relation to the chest did not change during acceleration up to +7 Gz. The success in maintaining high‐quality images during exposures to G‐forces of this magnitude may he attributed to the relatively low rate of G onset. End‐diastolic volumes (EDV) and stroke volumes (SV) decreased during a +Gz acceleration ramp that increased until the subject experienced peripheral light loss (PLL) ( P > .05). An inflated G‐suit partially counteracted this effect. By 30 seconds of a +3 Gz acceleration plateau, the protective effects of the inflated G‐suit to maintain EDV is lost and the EDV of the inflated G‐suit was lower than the EDV of the uninflated G‐suit ( P > .05) .