Doppler echocardiographic-determined changes in left ventricular diastolic filling flow velocity during the lower body positive and negative pressure method

1990 ◽  
Vol 65 (3) ◽  
pp. 237-241 ◽  
Author(s):  
Toshiyuki Takahashi ◽  
Masahiko Iizuka ◽  
Hiroshi Sato ◽  
Takashi Serizawa ◽  
Shin-ichi Momomura ◽  
...  
Keyword(s):  
Flow Velocity ◽  
Negative Pressure ◽  
Left Ventricular ◽  
Diastolic Filling ◽  
Lower Body ◽  
Pressure Method ◽  
Body Positive ◽  
Left Ventricular Diastolic Filling

Simulation of cardiovascular response to lower body negative pressure from 0 to -40 mmHg

1994 ◽  
Vol 77 (2) ◽  
pp. 630-640 ◽  
Author(s):  
F. M. Melchior ◽  
R. S. Srinivasan ◽  
P. H. Thullier ◽  
J. M. Clere
Keyword(s):  
Heart Rate ◽  
Negative Pressure ◽  
Baroreflex Sensitivity ◽  
Lower Body Negative Pressure ◽  
Cardiovascular Response ◽  
Left Ventricular ◽  
Diastolic Filling ◽  
Lower Body ◽  
Arterial Baroreflex ◽  
Arterial Baroreflex Sensitivity

This paper presents a mathematical model for simulation of the human cardiovascular response to lower body negative pressure (LBNP) up to -40 mmHg both under normal conditions and when arterial baroreflex sensitivity or leg blood capacity (LBC) is altered. Development of the model assumes that the LBNP response could be explained solely on the bases of 1) blood volume redistribution, 2) left ventricular end-diastolic filling, 3) interaction between left ventricle and peripheral circulation, and 4) modulations of peripheral resistances and heart rate by arterial and cardiopulmonary baroreflexes. The model reproduced well experimental data obtained both under normal conditions and during complete autonomic blockade; thus it is validated for simulation of the cardiovascular response from 0 to -40 mmHg LBNP. We tested the ability of the model to simulate the changes in LBNP response due to a reduction in LBC. To assess these changes experimentally, six healthy men were subjected to LBNP of -15, -30, and -38 mmHg with and without wearing elastic compression stockings. Stockings significantly reduced LBC (from 3.9 +/- 0.3 to 1.8 +/- 0.4 ml/100 ml tissue at -38 mmHg LBNP; P < 0.01) and attenuated the change in heart rate (from 23 +/- 4 to 8 +/- 3% at -38 mmHg LBNP; P < 0.05). The model accurately reproduced this result. The model is useful for assessing the influence of LBC or other parameters such as arterial baroreflex sensitivity in diminishing the orthostatic tolerance of humans after spaceflight, bed rest, or endurance training.

Right and Left Ventricular Diastolic Filling Parameters in Essential Hypertension

1999 ◽  
Vol 7 (3) ◽  
pp. 214-220 ◽  
Author(s):  
Azad Akkoç ◽  
Berzal Uçaman ◽  
Halil Kaymak ◽  
Ali Vahip Temamoğullari ◽  
Kenan Iltümür ◽  
...  
Keyword(s):  
Essential Hypertension ◽  
Left Ventricular ◽  
Diastolic Filling ◽  
Left Ventricular Diastolic Filling

Effects of verapamil on left ventricular diastolic filling in children with hypertrophic cardiomyopathy

1988 ◽  
Vol 61 (6) ◽  
pp. 413-417 ◽  
Author(s):  
Elizabeth M. Shaffer ◽  
Albert P. Rocchini ◽  
Robert L. Spicer ◽  
Jack Juni ◽  
Rebecca Snider ◽  
...  
Keyword(s):  
Hypertrophic Cardiomyopathy ◽  
Left Ventricular ◽  
Diastolic Filling ◽  
Left Ventricular Diastolic Filling

Hemodynamic and hormonal effects of prolonged anti-G suit inflation in humans

1992 ◽  
Vol 72 (3) ◽  
pp. 977-984 ◽  
Author(s):  
G. Geelen ◽  
P. Arbeille ◽  
J. L. Saumet ◽  
J. M. Cottet-Emard ◽  
F. Patat ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Plasma Renin Activity ◽  
Plasma Renin ◽  
Left Ventricular ◽  
Renin Activity ◽  
Positive Pressure ◽  
Plasma Norepinephrine ◽  
Lower Body ◽  
Lower Body Positive Pressure ◽  
Body Positive

This study examined the hemodynamic consequences of prolonged lower body positive-pressure application and their relationship to changes in the plasma concentration of the major vasoactive hormones. Six men [36 +/- 2 (SE) yr] underwent 30 min of sitting and then 3 h of 70 degrees head-up tilt. An antigravity suit was applied (60 Torr legs, 30 Torr abdomen) during the last 2 h of tilt. In a similar noninflation experiment, the endocrine responses were measured in the suited subjects tilted for 3 h. Two-dimensional echocardiography was used to calculate ventricular volume and cardiac output. Measurements were made 30 min before and 30 and 90 min after inflation. Immediately after inflation, mean arterial pressure increased by 7 +/- 2 Torr and heart rate decreased by 16 +/- 4 beats/min. Left ventricular end-diastolic volume and systolic volume increased significantly (P less than 0.05) at 30 and 90 min of inflation. Cardiac output increased after 30 min of inflation and returned to the preinflation level at 90 min. Plasma norepinephrine and plasma renin activity were maximally suppressed after 15 and 90 min of inflation, respectively (P less than 0.05). No such hormonal changes occurred during control. Plasma sodium, potassium, and osmolality remained unchanged during both experiments. Thus, prolonged application of lower body positive pressure induces 1) a transient increase in cardiac output and 2) a marked and sustained decrease in plasma norepinephrine and plasma renin activity, which reflect an inflation-induced decrease in sympathetic activity.

Relation of Left Ventricular Diastolic Filling to Age and Left Ventricular Hypertrophy

1989 ◽  
Vol 19 (2) ◽  
pp. 283
Author(s):  
Won Kyo Suh ◽  
Chung Whee Choue ◽  
Kwon Sam Kim ◽  
Myung Shick Kim ◽  
Jung Sang Song ◽  
...  
Keyword(s):  
Left Ventricular Hypertrophy ◽  
Ventricular Hypertrophy ◽  
Left Ventricular ◽  
Diastolic Filling ◽  
Left Ventricular Diastolic Filling
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