The effects of lower body compression on left ventricular rotational mechanics in lymphoedema (from the MAGYAR‐Path Study)

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.

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Maturational patterns of left ventricular rotational mechanics in pre-term infants through 1 year of age

Cardiology in the Young ◽

10.1017/s1047951120001912 ◽

2020 ◽

Vol 30 (9) ◽

pp. 1238-1246

Author(s):

Gloria C. Lehmann ◽

Philip T. Levy ◽

Meghna D. Patel ◽

Timothy Sekarski ◽

HongJie Gu ◽

...

Keyword(s):

Repeated Measures ◽

Neonatal Period ◽

Ductus Arteriosus ◽

Left Ventricular ◽

Term Infants ◽

Apical Rotation ◽

Cardiopulmonary Complications ◽

Rotational Mechanics ◽

The Impact ◽

Over Time

AbstractBackground:Pre-mature birth impacts left ventricular development, predisposing this population to long-term cardiovascular risk. The aims of this study were to investigate maturational changes in rotational properties from the neonatal period through 1 year of age and to discern the impact of cardiopulmonary complications of pre-maturity on these measures.Methods:Pre-term infants (<29 weeks at birth, n = 117) were prospectively enrolled and followed to 1-year corrected age. Left ventricular basal and apical rotation, twist, and torsion were measured by two-dimensional speckle-tracking echocardiography and analysed at 32 and 36 weeks post-menstrual age and 1-year corrected age. A mixed random effects model with repeated measures analysis was used to compare rotational mechanics over time. Torsion was compared in infants with and without complications of cardiopulmonary diseases of pre-maturity, specifically bronchopulmonary dysplasia, pulmonary hypertension, and patent ductus arteriosus.Results:Torsion decreased from 32 weeks post-menstrual age to 1-year corrected age in all pre-term infants (p < 0.001). The decline from 32 to 36 weeks post-menstrual age was more pronounced in infants with cardiopulmonary complications, but was similar to healthy pre-term infants from 36 weeks post-menstrual age to 1-year corrected age. The decline was due to directional and magnitude changes in apical rotation over time (p < 0.05).Conclusion:This study tracks maturational patterns of rotational mechanics in pre-term infants and reveals torsion declines from the neonatal period through 1 year. Cardiopulmonary diseases of pre-maturity may negatively impact rotational mechanics during the neonatal period, but the myocardium recovers by 1-year corrected age.

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Simultaneous multi-slice excitation for single breath hold estimates of left ventricular rotational mechanics

Journal of Cardiovascular Magnetic Resonance ◽

10.1186/1532-429x-18-s1-o109 ◽

2016 ◽

Vol 18 (S1) ◽

Author(s):

Zhe Wang ◽

Fei Han ◽

Yi Wang ◽

Peng Hu ◽

Daniel B Ennis

Keyword(s):

Left Ventricular ◽

Breath Hold ◽

Single Breath ◽

Single Breath Hold ◽

Rotational Mechanics

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Left Ventricular Rotational Mechanics in Children After Heart Transplantation

Circulation Cardiovascular Imaging ◽

10.1161/circimaging.116.004848 ◽

2016 ◽

Vol 9 (9) ◽

Cited By ~ 10

Author(s):

Hythem M. Nawaytou ◽

Putri Yubbu ◽

Andrea E. Montero ◽

Deipanjan Nandi ◽

Matthew J. O’Connor ◽

...

Keyword(s):

Heart Transplantation ◽

Left Ventricular ◽

Rotational Mechanics

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Lower body negative pressure vs. lower body positive pressure to prevent cardiac atrophy after bed rest and spaceflight. What caused the controversy?

Journal of Applied Physiology ◽

10.1152/japplphysiol.00950.2005 ◽

2006 ◽

Vol 100 (3) ◽

pp. 1090-1090 ◽

Cited By ~ 2

Author(s):

Marieta V. Pancheva ◽

Vladimir S. Panchev ◽

Adelina V. Suvandjieva

Keyword(s):

Cardiac Muscle ◽

Bed Rest ◽

Left Ventricular ◽

Physiological Adaptation ◽

Positive Pressure ◽

Loading Conditions ◽

Lower Body ◽

Cardiac Atrophy ◽

End Diastolic Volume ◽

Lv Mass

Cardiac muscle adapts well to changes in loading conditions. For example, left ventricular (LV) hypertrophy may be induced physiologically (via exercise training) or pathologically (via hypertension or valvular heart disease). If hypertension is treated, LV hypertrophy regresses, suggesting a sensitivity to LV work. However, whether physical inactivity in nonathletic populations causes adaptive changes in LV mass or even frank atrophy is not clear. We exposed previously sedentary men to 6 ( n = 5) and 12 ( n = 3) wk of horizontal bed rest. LV and right ventricular (RV) mass and end-diastolic volume were measured using cine magnetic resonance imaging (MRI) at 2, 6, and 12 wk of bed rest; five healthy men were also studied before and after at least 6 wk of routine daily activities as controls. In addition, four astronauts were exposed to the complete elimination of hydrostatic gradients during a spaceflight of 10 days. During bed rest, LV mass decreased by 8.0 ± 2.2% ( P = 0.005) after 6 wk with an additional atrophy of 7.6 ± 2.3% in the subjects who remained in bed for 12 wk; there was no change in LV mass for the control subjects (153.0 ± 12.2 vs. 153.4 ± 12.1 g, P = 0.81). Mean wall thickness decreased (4 ± 2.5%, P = 0.01) after 6 wk of bed rest associated with the decrease in LV mass, suggesting a physiological remodeling with respect to altered load. LV end-diastolic volume decreased by 14 ± 1.7% ( P = 0.002) after 2 wk of bed rest and changed minimally thereafter. After 6 wk of bed rest, RV free wall mass decreased by 10 ± 2.7% ( P = 0.06) and RV end-diastolic volume by 16 ± 7.9% ( P = 0.06). After spaceflight, LV mass decreased by 12 ± 6.9% ( P = 0.07). In conclusion, cardiac atrophy occurs during prolonged (6 wk) horizontal bed rest and may also occur after short-term spaceflight. We suggest that cardiac atrophy is due to a physiological adaptation to reduced myocardial load and work in real or simulated microgravity and demonstrates the plasticity of cardiac muscle under different loading conditions.

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Left ventricular function during arm exercise: influence of leg cycling and lower body positive pressure

Journal of Applied Physiology ◽

10.1152/japplphysiol.00511.2006 ◽

2007 ◽

Vol 102 (3) ◽

pp. 904-912 ◽

Cited By ~ 4

Author(s):

Jack M. Goodman ◽

Michael R. Freeman ◽

Leonard S. Goodman

Keyword(s):

Left Ventricular ◽

Cell Labeling ◽

Positive Pressure ◽

Lower Body ◽

Arm Exercise ◽

Lower Body Positive Pressure ◽

End Diastolic Volume ◽

Body Positive ◽

Leg Cycling ◽

Leg Exercise

The purpose of this study was to characterize left ventricular (LV) diastolic filling and systolic performance during graded arm exercise and to examine the effects of lower body positive pressure (LBPP) or concomitant leg exercise as means to enhance LV preload in aerobically trained individuals. Subjects were eight men with a mean age (±SE) of 26.8 ± 1.2 yr. Peak exercise testing was first performed for both legs [maximal oxygen uptake (V̇o2) = 4.21 ± 0.19 l/min] and arms (2.56 ± 0.16 l/min). On a separate occasion, LV filling and ejection parameters were acquired using non-imaging scintography using in vivo red blood cell labeling with technetium 99m first during leg exercise performed in succession for 2 min at increasing grades to peak effort. Graded arm exercise (at 30, 60, 80, and 100% peak V̇o2) was performed during three randomly assigned conditions: control (no intervention), with concurrent leg cycling (at a constant 15% leg maximal V̇o2) or with 60 mmHg of LBPP using an Anti G suit. Peak leg exercise LV ejection fraction was higher than arm exercise (60.9 ± 1.7% vs. 55.9 ± 2.7%; P < 0.05) as was peak LV end-diastolic volume was reported as % of resting value (110.3 ± 4.4% vs. 97 ± 3.7%; P < 0.05) and peak filling rate (end-diastolic volume/s; 6.4 ± 0.28% vs. 5.2 ± 0.25%). Concomitant use of either low-intensity leg exercise or LBPP during arm exercise failed to significantly increase LV filling or ejection parameters. These observations suggest that perturbations in preload fail to overcome the inherent hemodynamic conditions present during arm exercise that attenuate LV performance.

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