scholarly journals Early cardiovascular sympathetic reflex activation is independent of occlusion time during reactive hyperemia

2021 ◽  
Author(s):  
Erislandis López-Galán ◽  
Adán Andreu-Heredia ◽  
Ramón Carrazana-Escalona ◽  
Odalis Querts Méndez ◽  
Juan Carlos García Naranjo ◽  
...  
Keyword(s):  
Reactive Hyperemia ◽  
Occlusion Time ◽  
Reflex Activation

Cerebral blood flow during elevation of intracranial pressure: role of sympathetic nerves

1981 ◽  
Vol 241 (1) ◽  
pp. H78-H84 ◽  
Author(s):  
S. Sadoshima ◽  
M. Thames ◽  
D. Heistad
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Intracranial Pressure ◽  
Intracranial Hypertension ◽  
Reactive Hyperemia ◽  
Sympathetic Nerves ◽  
Base Line ◽  
Artificial Cerebrospinal Fluid ◽  
Reflex Activation

This study was performed to examine effects of increased intracranial pressure on cerebral blood flow (CBF) and to determine if sympathetic nerves modulate this response. Intracranial pressure was raised by infusion of artificial cerebrospinal fluid into a lateral ventricle of rabbits. Increases in intracranial pressure were similar in the lateral ventricles and cisterna magna. Graded increases in intracranial pressure from base line of 7 to 96 mmHg produced graded reductions in CBF (measured with microspheres). Reductions in blood flow were heterogeneous: elevation of intracranial pressure from 7 +/- 1 to 46 +/- 3 (SE) mmHg reduced blood flow to the cerebrum by 33 +/- 5% and blood flow to the medulla by only 5 +/- 2% (P less than 0.05). Reduction of intracranial pressure to normal levels produced marked reactive hyperemia in all areas of the brain. Although sympathetic nerve traffic increased fivefold during intracranial hypertension, superior cervical ganglionectomy did not affect CBF. In other experiments, electrical stimulation of sympathetic nerves at 4 Hz reduced blood flow to skeletal muscle by 80% but did not affect CBF; stimulation at 15 Hz produced a modest reduction in CBF. We conclude that 1) during increases in intracranial pressure, blood flow is better preserved to the medulla than to the cerebrum despite similar intracranial pressure in the two areas and 2) intense reflex activation of sympathetic nerves during intracranial hypertension does not affect CBF.

Dependence of human forearm skin postocclusive reactive hyperemia on occlusion time

2004 ◽  
Vol 50 (1) ◽  
pp. 73-78 ◽  
Author(s):  
Get Bee Yvonne Tee ◽  
Aida Hanum Ghulam Rasool ◽  
Ahmad Sukari Halim ◽  
Abdul Rashid Abdul Rahman
Keyword(s):  
Reactive Hyperemia ◽  
Occlusion Time ◽  
Human Forearm ◽  
Forearm Skin ◽  
Postocclusive Reactive Hyperemia

Ventilatory threshold is related to walking tolerance in patients with intermittent claudication

VASA ◽  
2012 ◽  
Vol 41 (4) ◽  
pp. 275-281 ◽  
Author(s):  
da Rocha Chehuen ◽  
G. Cucato ◽  
P. dos Anjos Souza Barbosa ◽  
A. R. Costa ◽  
M. Ritti-Dias ◽  
...  
Keyword(s):  
Blood Flow ◽  
Oxygen Uptake ◽  
Intermittent Claudication ◽  
Lower Limb ◽  
Ventilatory Threshold ◽  
Reactive Hyperemia ◽  
Ankle Brachial Index ◽  
Metabolic Parameters ◽  
Walking Distance ◽  
The Relationship

Background: This study assessed the relationship between lower limb hemodynamics and metabolic parameters with walking tolerance in patients with intermittent claudication (IC). Patients and methods: Resting ankle-brachial index (ABI), baseline blood flow (BF), BF response to reactive hyperemia (BFRH), oxygen uptake (VO2), initial claudication distance (ICD) and total walking distance (TWD) were measured in 28 IC patients. Pearson and Spearman correlations were calculated. Results: ABI, baseline BF and BF response to RH did not correlate with ICD or TWD. VO2 at first ventilatory threshold and VO2peak were significantly and positively correlated with ICD (r = 0.41 and 0.54, respectively) and TWD (r = 0.65 and 0.71, respectively). Conclusions: VO2peak and VO2 at first ventilatory threshold, but not ABI, baseline BF and BFHR were associated with walking tolerance in IC patients. These results suggest that VO2 at first ventilatory threshold may be useful to evaluate walking tolerance and improvements in IC patients.

scholarly journals Determination of optimal deployment strategy for REBOA in patients with non-compressible hemorrhage below the diaphragm

2021 ◽  
Vol 6 (1) ◽  
pp. e000660
Author(s):  
Nicholas L Johnson ◽  
Charles E Wade ◽  
Erin E Fox ◽  
David E Meyer ◽  
Charles J Fox ◽  
...  
Keyword(s):  
Primary Source ◽  
Multiple Organ ◽  
Balloon Occlusion ◽  
Hemorrhage Control ◽  
Level Of Evidence ◽  
Occlusion Time ◽  
Deployment Strategy ◽  
Multicenter Prospective Observational Study ◽  
Selection Algorithms ◽  
Post Hoc

BackgroundNon-compressible truncal hemorrhage (NCTH) is the leading cause of preventable death after trauma. Resuscitative endovascular balloon occlusion of the aorta (REBOA) achieves temporary hemorrhage control, supporting cardiac and cerebral perfusion prior to definitive hemostasis. Aortic zone selection algorithms vary among institutions. We evaluated the efficacy of an algorithm for REBOA use.MethodsA multicenter prospective, observational study conducted at six level 1 trauma centers over 12 months. Inclusion criteria were age >15 years with evidence of infradiaphragmatic NCTH needing emergent hemorrhage control within 60 min of ED arrival. An algorithm characterized by the results of focused assessment with sonography in trauma and pelvic X-ray was assessed post hoc for efficacy in a cohort of patients receiving REBOA.ResultsOf the 8166 patients screened, 78 patients had a REBOA placed. 21 patients were excluded, leaving 57 patients for analysis. The algorithm ensures REBOA deployment proximal to hemorrhage source to control bleeding in 98.2% of cases and accurately predicts the optimal REBOA zone in 78.9% of cases. If the algorithm was violated, bleeding was optimally controlled in only 43.8% (p=0.01). Three (75.0%) of the patients that received an inappropriate zone 1 REBOA died, two from multiple organ failure (MOF). All three patients that died with an inappropriate zone 3 REBOA died from exsanguination.DiscussionThis algorithm ensures proximal hemorrhage control and accurately predicts the primary source of hemorrhage. We propose a new algorithm that will be more inclusive. A zone 3 REBOA should not be performed when a zone 1 is indicated by the algorithm as 100% of these patients exsanguinated. MOF, perhaps from visceral ischemia in patients with an inappropriate zone 1 REBOA, may have been prevented with zone 3 placement or limited zone 1 occlusion time.Level of evidenceLevel III.

Using reactive hyperemia to investigate the effect of cupping sizes of cupping therapy on skin blood flow responses

2021 ◽  
pp. 1-7
Author(s):  
Xiangfeng He ◽  
Xueyan Zhang ◽  
Fuyuan Liao ◽  
Li He ◽  
Xin Xu ◽  
...  
Keyword(s):  
Blood Flow ◽  
Laser Doppler Flowmetry ◽  
Skin Blood Flow ◽  
Repeated Measures ◽  
Recovery Time ◽  
Reactive Hyperemia ◽  
Cupping Therapy ◽  
Doppler Flowmetry ◽  
Healthy Participants ◽  
Hyperemic Response

BACKGROUND: Various cupping sizes of cupping therapy have been used in managing musculoskeletal conditions; however, the effect of cupping sizes on skin blood flow (SBF) responses is largely unknown. OBJECTIVE: The objective of this study was to compare the effect of three cupping sizes of cupping therapy on SBF responses. METHODS: Laser Doppler flowmetry (LDF) was used to measure SBF on the triceps in 12 healthy participants in this repeated measures study. Three cup sizes (35, 40 and 45 mm in diameter) were blinded to the participants and were tested at -300 mmHg for 5 minutes. Reactive hyperemic response to cupping therapy was expressed as a ratio of baseline SBF. RESULTS: All three sizes of cupping cups resulted in a significant increase in peak SBF (p< 0.001). Peak SBF of the 45 mm cup (9.41 ± 1.32 times) was significantly higher than the 35 mm cup (5.62 ± 1.42 times, p< 0.05). Total SBF of the 45 mm cup ((24.33 ± 8.72) × 103 times) was significantly higher than the 35 mm cup ((8.05 ± 1.63) × 103 times, p< 0.05). Recovery time of the 45 mm cup (287.46 ± 39.54 seconds) was significantly longer than the 35 mm cup (180.12 ± 1.42 seconds, p< 0.05). CONCLUSIONS: Our results show that all three cup sizes can significantly increase SBF. The 45 mm cup is more effective in increasing SBF compared to the 35 mm cup.

Nailfold Capillaroscopy in Hypothyroidism and Hyperthyroidism: Blood Flow Velocity During Rest and Postocclusive Reactive Hyperemia

Angiology ◽  
1998 ◽  
Vol 49 (6) ◽  
pp. 471-476 ◽  
Author(s):  
Carmen C. Pazos-Moura ◽  
Egberto G. Moura ◽  
Marisa M. D. Breitenbach ◽  
Eliete Bouskela
Keyword(s):  
Blood Flow ◽  
Flow Velocity ◽  
Blood Flow Velocity ◽  
Reactive Hyperemia ◽  
Nailfold Capillaroscopy ◽  
Postocclusive Reactive Hyperemia

scholarly journals Effects of Monotherapy with Clopidogrel vs. Aspirin on Vascular Function and Hemostatic Measurements in Patients with Coronary Artery Disease: The Prospective, Crossover I-LOVE-MONO Trial

2021 ◽  
Vol 10 (12) ◽  
pp. 2720
Author(s):  
Hyun-Woong Park ◽  
Min-Gyu Kang ◽  
Jong-Hwa Ahn ◽  
Jae-Seok Bae ◽  
Udaya S. Tantry ◽  
...  
Keyword(s):  
Coronary Artery Disease ◽  
Coronary Artery ◽  
Endothelial Function ◽  
Vascular Function ◽  
Platelet Reactivity ◽  
Reactive Hyperemia ◽  
Open Label ◽  
Peripheral Arterial Tonometry ◽  
Coagulation Activity ◽  
Artery Disease

To evaluate the effect of clopidogrel vs. aspirin monotherapy on vascular function and hemostatic measurement. Background: Monotherapy with P2Y12 receptor inhibitor vs. aspirin can be a useful alterative to optimize clinical efficacy and safety in high-risk patients with coronary artery disease (CAD). Methods: We performed a randomized, open-label, two-period crossover study in stented patients receiving at least 6-month of dual antiplatelet therapy (DAPT). Thirty CAD patients with moderate-to-high ischemic risk were randomly assigned to receive either 75 mg of clopidogrel or 100 mg of aspirin daily for 4 weeks, and were crossed over to the other strategy for 4 weeks. Vascular function was evaluated with reactive hyperemia-peripheral arterial tonometry (RH-PAT) and brachial-ankle pulse wave velocity (baPWV). Hemostatic profiles were measured with VerifyNow and thromboelastography (TEG). The primary endpoint was the reactive hyperemia index (RHI) during clopidogrel or aspirin monotherapy. Results: Clopidogrel vs. aspirin monotherapy was associated with better endothelial function (RHI: 2.11 ± 0.77% vs. 1.87 ± 0.72%, p = 0.045), lower platelet reactivity (130 ± 64 vs. 214 ± 50 P2Y12 reaction unit [PRU], p < 0.001) and prolonged reaction time (TEG R: 5.5 ± 1.2 vs. 5.1 ± 1.1 min, p = 0.037). In multivariate analysis, normal endothelial function (RHI ≥ 2.1) was significantly associated with clot kinetics (TEG angle ≤ 68 degree) and ‘PRU ≤ 132’. ‘PRU ≤ 132’ was achieved in 46.2% vs. 3.8% during clopidogrel administration vs. aspirin monotherapy (odds ratio 21.4, 95% confidence interval 2.7 to 170.1, p < 0.001). Conclusions: In CAD patients, clopidogrel vs. aspirin monotherapy was associated with better endothelial function, greater platelet inhibition and lower coagulation activity, suggesting pleiotropic effects of clopidogrel on endothelial function and hemostatic profiles.

scholarly journals Novel Application of a Multiscale Entropy Index as a Sensitive Tool for Detecting Subtle Vascular Abnormalities in the Aged and Diabetic

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Hsien-Tsai Wu ◽  
Men-Tzung Lo ◽  
Guan-Hong Chen ◽  
Cheuk-Kwan Sun ◽  
Jian-Jung Chen
Keyword(s):  
Glycosylated Hemoglobin ◽  
Reactive Hyperemia ◽  
Multiscale Entropy ◽  
Arterial Pulse ◽  
Vascular Changes ◽  
Entropy Index ◽  
Pressure Sensing ◽  
Vascular Abnormalities ◽  
Sensing System ◽  
Sensitive Tool

Although previous studies have shown the successful use of pressure-induced reactive hyperemia as a tool for the assessment of endothelial function, its sensitivity remains questionable. This study aims to investigate the feasibility and sensitivity of a novel multiscale entropy index (MEI) in detecting subtle vascular abnormalities in healthy and diabetic subjects. Basic anthropometric and hemodynamic parameters, serum lipid profiles, and glycosylated hemoglobin levels were recorded. Arterial pulse wave signals were acquired from the wrist with an air pressure sensing system (APSS), followed by MEI and dilatation index (DI) analyses. MEI succeeded in detecting significant differences among the four groups of subjects: healthy young individuals, healthy middle-aged or elderly individuals, well-controlled diabetic individuals, and poorly controlled diabetic individuals. A reduction in multiscale entropy reflected age- and diabetes-related vascular changes and may serve as a more sensitive indicator of subtle vascular abnormalities compared with DI in the setting of diabetes.

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