scholarly journals The Effect of Lower Body Positive Pressure on Left Ventricular Ejection Duration in Patients With Heart Failure

Dose-Response ◽  
2018 ◽  
Vol 16 (4) ◽  
pp. 155932581881154
Author(s):  
Sriya Avadhani ◽  
Muhammad Ihsan ◽  
Arismendy Nunez ◽  
Haroon Kamran ◽  
Sahib Singh ◽  
...  
Keyword(s):  
Heart Failure ◽  
Body Weight ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Positive Pressure ◽  
Lv Function ◽  
Lower Body ◽  
Lower Body Positive Pressure ◽  
Patients With Heart Failure ◽  
Body Positive

Lower body positive pressure (LBPP) treadmill activity might benefit patients with heart failure (HF). To determine the short-term effects of LBPP on left ventricular (LV) function in HF patients, LV ejection duration (ED), a measure of systolic function was prospectively assessed in 30 men with stable HF with LV ejection fraction ≤ 40% and 50 healthy men (N). Baseline measurements (100% body weight), including blood pressure (BP), heart rate (HR) and LVED, obtained via radial artery applanation tonometry, were recorded after 2 minutes of standing on weight support treadmill and after LBPP achieving reductions of 25%, 50%, and 75% of body weight in random sequence. Baseline, HR, and LVED (251 ± 5 vs 264 ± 4 ms; P = .035) were lower in the HF group. The LBPP lowered HR more (14% vs 6%, P = .009) and increased LVED more (15% ± 7% vs 10% ± 6%; P = .004) in N versus HF. Neither group had changes (Δ) in BP. On generalized linear regression, the 2 groups showed different responses ( P < .001). Multivariate analysis showed %ΔHR ( P < .001) and HF ( P = .026) were predictive of ΔED ( r2 = 0.44; P < .001). In conclusion, progressive LBPP increases LVED in a step-wise manner in N and HF patients independent of HR lowering. The ΔLVED is less marked in patients with HF.

scholarly journals Effect of Uphill Running on VO2, Heart Rate and Lactate Accumulation on Lower Body Positive Pressure Treadmills

Sports ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 51
Author(s):  
Daniel Fleckenstein ◽  
Olaf Ueberschär ◽  
Jan C. Wüstenfeld ◽  
Peter Rüdrich ◽  
Bernd Wolfarth
Keyword(s):  
Heart Rate ◽  
Body Weight ◽  
Body Weight Support ◽  
Positive Pressure ◽  
Lower Body ◽  
Lactate Accumulation ◽  
Biomechanical Stress ◽  
Lower Body Positive Pressure ◽  
Weight Support ◽  
Body Positive

Lower body positive pressure treadmills (LBPPTs) as a strategy to reduce musculoskeletal load are becoming more common as part of sports conditioning, although the requisite physiological parameters are unclear. To elucidate their role, ten well-trained runners (30.2 ± 3.4 years; VO2max: 60.3 ± 4.2 mL kg−1 min−1) ran at 70% of their individual velocity at VO2max (vVO2max) on a LBPPT at 80% body weight support (80% BWSet) and 90% body weight support (90% BWSet), at 0%, 2% and 7% incline. Oxygen consumption (VO2), heart rate (HR) and blood lactate accumulation (LA) were monitored. It was found that an increase in incline led to increased VO2 values of 6.8 ± 0.8 mL kg−1 min−1 (0% vs. 7%, p < 0.001) and 5.4 ± 0.8 mL kg−1 min−1 (2% vs. 7%, p < 0.001). Between 80% BWSet and 90% BWSet, there were VO2 differences of 3.3 ± 0.2 mL kg−1 min−1 (p < 0.001). HR increased with incline by 12 ± 2 bpm (0% vs. 7%, p < 0.05) and 10 ± 2 bpm (2% vs. 7%, p < 0.05). From 80% BWSet to 90% BWSet, HR increases of 6 ± 1 bpm (p < 0.001) were observed. Additionally, LA values showed differences of 0.10 ± 0.02 mmol l−1 between 80% BWSet and 90% BWSet. Those results suggest that on a LBPPT, a 2% incline (at 70% vVO2max) is not yet sufficient to produce significant physiological changes in VO2, HR and LA—as opposed to running on conventional treadmills, where significant changes are measured. However, a 7% incline increases VO2 and HR significantly. Bringing together physiological and biomechanical factors from previous studies into this practical context, it appears that a 7% incline (at 80% BWSet) may be used to keep VO2 and HR load unchanged as compared to unsupported running, while biomechanical stress is substantially reduced.

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.

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

2007 ◽  
Vol 102 (3) ◽  
pp. 904-912 ◽  
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.

scholarly journals Physiological Responses to Treadmill Running With Body Weight Support in Hypoxia Compared With Normoxia

2018 ◽  
Vol 27 (3) ◽  
pp. 224-229 ◽  
Author(s):  
Ben J. Lee ◽  
Charles Douglas Thake
Keyword(s):  
Heart Rate ◽  
Body Weight ◽  
Metabolic Response ◽  
Treadmill Running ◽  
Positive Pressure ◽  
Lower Body ◽  
Physiological Strain ◽  
Sports Clubs ◽  
Lower Body Positive Pressure ◽  
Body Positive

Context: Anecdotal reports suggest elite sports clubs combine lower-body positive-pressure rehabilitation with a hypoxic stimulus to maintain or increase physiological and metabolic strain, which are reduced during lower-body positive pressure. However, the effects of hypoxia on cardiovascular and metabolic response during lower-body positive-pressure rehabilitation are unknown. Objective: Evaluate the use of normobaric hypoxia as a means to increase physiological strain during body-weight-supported (BWS) running. Design: Crossover study. Setting: Controlled laboratory. Participants: Seven familiarized males (mean (SD): age, 20 (1) y; height, 1.77 (0.05) m; mass, 69.4 (5.1) kg; hemoglobin, 15.2 (0.8) g·dL−1) completed a normoxic and hypoxic (fraction of inspired oxygen [O2] = 0.14) trial, during which they ran at 8 km·h−1 on an AlterG™ treadmill with 0%, 30%, and 60% BWS in a randomized order for 10 minutes interspersed with 5 minutes of recovery. Main Outcome Measures: Arterial O2 saturation, heart rate, O2 delivery, and measurements of metabolic strain via indirect calorimetry. Results: Hypoxic exercise reduced hemoglobin O2 saturation and elevated heart rate at each level of BWS compared with normoxia. However, the reduction in hemoglobin O2 saturation was attenuated at 60% BWS compared with 0% and 30%, and consequently, O2 delivery was better maintained at 60% BWS. Conclusion: Hypoxia is a practically useful means of increasing physiological strain during BWS rehabilitation. In light of the maintenance of hemoglobin O2 saturation and O2 delivery at increasing levels of BWS, fixed hemoglobin saturations rather than a fixed altitude are recommended to maintain an aerobic stimulus.

scholarly journals Alterations in the Rate of Limb Movement Using a Lower Body Positive Pressure Treadmill Do Not Influence Respiratory Rate or Phase III Ventilation

2015 ◽  
Vol 2015 ◽  
pp. 1-4
Author(s):  
Michael J. Buono ◽  
Marissa Burnsed-Torres ◽  
Bethany Hess ◽  
Kristine Lopez ◽  
Catherine Ortiz ◽  
...  
Keyword(s):  
Body Weight ◽  
Metabolic Rate ◽  
Submaximal Exercise ◽  
Limb Movement ◽  
Phase Iii ◽  
Positive Pressure ◽  
Lower Body ◽  
Step Frequency ◽  
Lower Body Positive Pressure ◽  
Body Positive

The purpose of this study was to determine the effect of alterations in rate of limb movement on Phase III ventilation during exercise, independent of metabolic rate, gait style, and treadmill incline. Subjects completed five submaximal exercise bouts on a lower body positive pressure treadmill (AlterG P 200). The percent body weight for the five exercise bouts was 100, 87, 75, 63, and 50% and each was matched for carbon dioxide production (VCO2). Naturally, to match theVCO2while reducing the body weight up to 50% of normal required a significant increase in the treadmill speed from3.0±0.1to4.1±0.2mph, which resulted in a significant(P<0.05)increase in the mean step frequency (steps per minute) from118±10at 3 mph (i.e., 100% of body weight) to133±6at 4.1 mph (i.e., 50% of body weight). The most important finding was that significant increases in step frequency did not significantly alter minute ventilation or respiratory rate. Such results do not support an important role for the rate of limb movement in Phase III ventilation during submaximal exercise, when metabolic rate, gait style, and treadmill incline are controlled.

Brachial artery flow and dimension responses to lower body positive pressure in healthy and heart failure subjects

2016 ◽  
Vol 10 (4) ◽  
pp. e26-e27
Author(s):  
Muhammad Ihsan ◽  
Arismendy Nunez ◽  
Bryan Massay Massay ◽  
Andrew Levin ◽  
John Kral ◽  
...  
Keyword(s):  
Heart Failure ◽  
Brachial Artery ◽  
Positive Pressure ◽  
Lower Body ◽  
Lower Body Positive Pressure ◽  
Body Positive ◽  
Artery Flow

scholarly journals Cardiorespiratory and metabolic responses to exercise testing during lower-body positive pressure running

2020 ◽  
Vol 128 (4) ◽  
pp. 778-784
Author(s):  
Tim Brüssau ◽  
Robert Oehring ◽  
Stephan B. Felix ◽  
Marcus Dörr ◽  
Martin Bahls
Keyword(s):  
Body Weight ◽  
Perceived Exertion ◽  
Pulse Wave ◽  
Disease Risk ◽  
Rating Of Perceived Exertion ◽  
Cardiometabolic Disease ◽  
Positive Pressure ◽  
Lower Body ◽  
Lower Body Positive Pressure ◽  
Body Positive

Exercise reduces the future cardiometabolic disease risk. However, not everyone can participate in routine physical activity because of obesity or orthopedic impairments. Body weight-supported (BWS) exercise may be an option for these individuals. Unfortunately, very little data are available with regard to BWS running in untrained healthy individuals. Yet, this information is important to assess the potential use of lower-body positive pressure (LBPP) treadmill running for the prevention of cardiometabolic disease. Twenty healthy but untrained participants (10 females, mean age 31.5 yr) were included in this study. Participants completed two exercise tests (one with 100% and one with 60% body wt) in randomized order on a LBPP treadmill. Expired gas data and heart rate (HR) were collected continuously. Blood lactate, blood pressure (BP), pulse wave velocity (PWV), and rating of perceived exertion (RPE) were measured during a 2-min break after each stage. Oxygen uptake increased significantly independent of BWS but was lower with BWS. Furthermore, we identified a significant correlation between HR and RPE independent of BWS. BP and PWV showed a large heterogeneity in response to BWS. The lower O2 requirement when running with BWS may help untrained individuals to adapt to an exercise regimen. Future research needs to explore the heterogenetic response of blood pressure and pulse wave velocity to LBPP BWS between individuals. NEW & NOTEWORTHY Lower-body positive pressure body weight-supported exercise has a lower metabolic and cardiovascular demand. Furthermore, heart rate and rating of perceived exertion are highly correlated independent of body weight support. Our data support the further examination of lower-body positive pressure exercise training for cardiovascular disease risk groups.

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