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J Cereb Blood Flow Metab 2021 Apr 14:271678X211007957. Epub 2021 Apr 14.

Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, USA.

Local blood flow in the brain is tightly coupled to metabolic demands, a phenomenon termed functional hyperemia. Both capillaries and arterioles contribute to the hyperemic response to neuronal activity via different mechanisms and timescales. The nature and specific signaling involved in the hyperemic response of capillaries versus arterioles, and their temporal relationship are not fully defined. Read More

Curr Tissue Microenviron Rep 2020 Dec 30;1(4):163-169. Epub 2020 Oct 30.

Knight Cardiovascular Institute Oregon Health & Science University, Portland, Oregon, USA.

Purpose: The microvascular capillary network is ensheathed by cells called pericytes - a heterogeneous population of mural cells derived from multiple lineages. Pericytes play a multifaceted role in the body, including in vascular structure and permeability, regulation of local blood flow, immune and wound healing functions, induction of angiogenesis, and generation of various progenitor cells. Here, we consider the role of pericytes in capillary de-recruitment, a pathophysiologic phenomenon that is observed following hyperemic stimuli in the presence of a stenosis and attenuates the hyperemic response. Read More

J Appl Physiol (1985) 2021 Mar 25. Epub 2021 Mar 25.

Department of Kinesiology, The University of Texas at Arlington, United States.

Non-Hispanic black individuals have an elevated prevalence of cardiovascular disease in large part, related to impaired vascular function, secondary to reduced nitric oxide (NO) bioavailability. Nitrate supplementation increases NO bioavailability and improves vascular function. This study tested the hypothesis that forearm blood flow responses in young, non-Hispanic, black (BL) men during mental stress are blunted relative to, non-Hispanic, white (WH) men and that acute dietary nitrate supplementation would improve this response in BL men. Read More

Alzheimers Dement 2021 Mar 3. Epub 2021 Mar 3.

Neurology, Box 2900, Duke University Medical Center, Durham, North Carolina, 27710, USA.

We compared the efficacy of neurovascular coupling and substrate supply in cerebral cortex during severe metabolic challenges in transgenic Alzheimer's [CVN-AD] and control [C57Bl/6] mice, to evaluate the hypothesis that metabolic insufficiency is a critical component of degeneration leading to dementia. We analyzed cerebral blood flow and metabolic responses to spreading depression (induced by K applied to the cortex) and anoxia across aging in CVN-AD + C57Bl/6 genotypes. In the CVN-AD genotype progression to histological and cognitive hallmarks of dementia is a stereotyped function of age. Read More

Korean Circ J 2021 Feb;51(2):126-139

Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai Institute of Cardiovascular Diseases, Shanghai, China.

Background And Objectives: Quantitative flow ratio (QFR) is an angiography-based technique for functional assessment of coronary artery stenosis. This study investigated the response of QFR to different degree of stenosis severity and its ability to predict the positron emission tomography (PET)-defined myocardial ischemia.

Methods: From 109 patients with 185 vessels who underwent both 13N-ammonia PET and invasive physiological measurement, we compared QFR, fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) for the responses to the different degree of anatomical (percent diameter stenosis [%DS]) and hemodynamic (relative flow reserve [RFR], coronary flow reserve, hyperemic stenosis resistance, and stress myocardial flow) stenosis severity and diagnostic performance against PET-derived parameters. Read More

Mol Cell Biochem 2021 Jan 28. Epub 2021 Jan 28.

Pharmaceutical Sciences, School of Pharmacy, Center for Basic and Translational Stroke Research, West Virginia University Morgantown, Morgantown, WV, USA.

Previously, we have reported that the coronary reactive hyperemic response was reduced in adenosine A receptor-null (AAR) mice, and it was reversed by the soluble epoxide hydrolase (sEH) inhibitor. However, it is unknown in aortic vascular response, therefore, we hypothesized that AAR-gene deletion in mice (AAR) affects adenosine-induced vascular response by increase in sEH and adenosine A receptor (AAR) activities. AAR mice showed an increase in sEH, A AR and CYP450-4A protein expression but decrease in CYP450-2C compared to C57Bl/6 mice. Read More

J Back Musculoskelet Rehabil 2021 ;34(2):327-333

Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Champaign, IL, USA.

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. Read More

Am J Physiol Heart Circ Physiol 2021 03 15;320(3):H991-H998. Epub 2021 Jan 15.

Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine, University of Iowa, Iowa City, Iowa.

Aging causes deleterious changes in resting conduit artery shear patterns and reduced blood flow during exercise partially attributable to reduced nitric oxide (NO). Inorganic nitrate increases circulating NO bioavailability and may, therefore, improve age-associated changes in shear rate as well as exercise hyperemia. Ten older adults (age: 67 ± 3 yr) consumed 4. Read More

PLoS One 2021 7;16(1):e0244795. Epub 2021 Jan 7.

Department of Kinesiology, Iowa State University, Ames, Iowa, United States of America.

Background: Impaired perfusion indices signal potential microvascular dysfunction preceding atherosclerosis and other cardiometabolic pathologies. Post-occlusive reactive hyperemia (PORH), a vasodilatory response following a mechanically induced ischemia, is a transient increase in perfusion and can assess microvascular function. The greatest blood flow change corresponding to the first minute of hyperemia (represented by time-to-peak, hyperemic velocity, AUC within 1st min) has been shown to indicate microvascular dysfunction. Read More

J Cardiovasc Magn Reson 2021 Jan 7;23(1). Epub 2021 Jan 7.

Department of Nuclear Medicine, Cardiac Imaging, University Hospital Zurich and University Zurich, Ramistrasse 100, 8091, Zurich, Switzerland.

Background: Inadequate coronary adenosine response is a potential cause for false negative ischemia testing. Recently, the splenic switch-off (SSO) sign has been identified as a promising tool to ascertain the efficacy of adenosine during vasodilator stress cardiovascular magnetic resonance imaging (CMR). We assessed the value of SSO to predict adenosine response, defined as an increase in myocardial blood flow (MBF) during quantitative stress myocardial perfusion 13 N-ammonia positron emission tomography (PET). Read More

J Dent Sci 2021 Jan 4;16(1):249-255. Epub 2020 Jun 4.

Department of Oral Biology, Faculty of Dentistry, Mahidol University, Bangkok, Thailand.

Background/purpose: Local anesthetics and anesthetic techniques affect the patterns of pulpal blood flow (PBF) and pulpal anesthesia in human teeth. This study aimed to determine PBF changes and pulpal anesthesia of intact mandibular first molars and canines after administration of 4% articaine with epinephrine 1:100,000 using inferior alveolar nerve block (IANB).

Materials And Methods: Ten healthy subjects received IANB of 4% articaine with epinephrine 1:100,000. Read More

Am J Physiol Heart Circ Physiol 2021 02 11;320(2):H668-H678. Epub 2020 Dec 11.

Geriatric Research, Education, and Clinical Center, Department of Veterans Affairs Medical Center, Salt Lake City, Utah.

Passive leg movement (PLM) evokes a robust and predominantly nitric oxide (NO)-mediated increase in blood flow that declines with age and disease. Consequently, PLM is becoming increasingly accepted as a sensitive assessment of endothelium-mediated vascular function. However, a substantial PLM-induced hyperemic response is still evoked despite nitric oxide synthase (NOS) inhibition. Read More

Am J Physiol Heart Circ Physiol 2021 01 4;320(1):H23-H28. Epub 2020 Dec 4.

Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.

In neural tissues, the coupling between neural activity and blood flow is a physiological key principle in blood flow regulation. We used optical coherence tomography angiography to investigate stimulus-evoked hemodynamic responses in different microvascular layers of the human retina. Twenty-two healthy subjects were included. Read More

Am J Physiol Heart Circ Physiol 2021 01 20;320(1):H144-H158. Epub 2020 Nov 20.

Laboratory for Structural, Physiologic and Functional Imaging, Department of Radiology.

This study was designed to investigate the acute effects of nonnicotinized e-cigarette (e-cig) aerosol inhalation in nonsmokers both in terms of blood-based markers of inflammation and oxidative stress and evaluate their association with hemodynamic-metabolic MRI parameters quantifying peripheral vascular reactivity, cerebrovascular reactivity, and aortic stiffness. Thirty-one healthy nonsmokers were subjected to two blood draws and two identical MRI protocols, each one before and after a standardized e-cig vaping session. After vaping, the serum levels of C-reactive protein, soluble intercellular adhesion molecule, and the danger signal machinery high-mobility group box 1 (HMGB1) and its downstream effector and the NLR family pyrin domain containing 3 (NLRP3) inflammasome (as monitored by its adaptor protein ASC) increased significantly relative to the respective baseline (prevaping) values. Read More

J Hum Hypertens 2020 Nov 9. Epub 2020 Nov 9.

Exercise & Sport Science Department, Western Colorado University, Paul Wright Gym 209, 1 Western Way, Gunnison, CO, 81231, USA.

The extent that clustered CVD risk factors interfere with ischemic preconditioning (IPC) to protect against microvascular endothelial dysfunction with ischemia-reperfusion (I/R) injury in humans is unclear. We hypothesized that adults with a clustered burden of ≥3 CVD risk factors would demonstrate a reduced capacity of IPC to protect endothelial function with I/R injury. Twenty-two (age: 45 ± 14 year) adults [12 healthy controls; 10 raised risk (10-year FRS risk score ~3%)] were studied using a 2 × 2 randomized cross-over design. Read More

Cardiol J 2020 Nov 3. Epub 2020 Nov 3.

1st Clinic and Department of Cardiology, Medical University of Lodz, Lodz, Poland.

Background: This pilot study revealed a relationship between the results of flow mediated skin fluorescence (FMSF) and of ECG-Holter-based estimated apnea/hypopnea index (eAHI) in asymptomatic individuals. The aim was to test whether the results of FMSF show a relationship with the eAHI in patients with coronary artery disease or aortic stenosis.

Methods: Twenty-one patients (12 coronary disease, 9 aortic stenosis) and 37 healthy volunteers were included in this study. Read More

Catheter Cardiovasc Interv 2020 Sep 9. Epub 2020 Sep 9.

Division of Cardiology, Department of Internal Medicine, Emory Clinical Cardiovascular Research Institute, Atlanta, Georgia, USA.

Background: Patients without obstructive coronary artery disease (CAD) may have epicardial or microvascular dysfunction. The purpose of this study was to characterize patterns of epicardial and microvascular dysfunction in men and women with stable and unstable angina undergoing functional coronary angiography to inform medical therapy.

Methods: 163 symptomatic patients with ≤50% diameter stenosis and fractional flow reserve (FFR) > 0. Read More

J Clin Med 2020 09 1;9(9). Epub 2020 Sep 1.

Department of Clinical Pharmacology, Medical University Vienna, 1090 Vienna, Austria.

Neurovascular coupling, also termed functional hyperemia, is one of the physiological key mechanisms to adjust blood flow in a neural tissue in response to functional activity. In the retina, increased neural activity, such as that induced by visual stimulation, leads to the dilatation of retinal arterioles, which is accompanied by an immediate increase in retinal and optic nerve head blood flow. According to the current scientific view, functional hyperemia ensures the adequate supply of nutrients and metabolites in response to the increased metabolic demand of the neural tissue. Read More

Am J Physiol Heart Circ Physiol 2020 10 21;319(4):H797-H807. Epub 2020 Aug 21.

Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine, University of Iowa, Iowa City, Iowa.

Patients with type 2 diabetes mellitus (T2DM) exhibit diminished exercise capacity likely attributable to reduced skeletal muscle blood flow (i.e., exercise hyperemia). Read More

J Am Heart Assoc 2020 08 21;9(15):e015793. Epub 2020 Jul 21.

U955-IMRB Equipe 03 Inserm UPEC Ecole Nationale Vétérinaire d'Alfort Maisons-Alfort France.

Background Absolute hyperemic coronary blood flow and microvascular resistances can be measured by continuous thermodilution with a dedicated infusion catheter. We aimed to determine the mechanisms of this hyperemic response in animal. Methods and Results Twenty open chest pigs were instrumented with flow probes on coronary arteries. Read More

Hypertension 2020 08 8;76(2):342-349. Epub 2020 Jul 8.

Department of Internal Medicine (A.F.J.G., M.J.M.v.A., C.D.A.S., B.M.S., N.C.S., R.M.A.H., C.J.H.v.d.K., T.T.v.S., M.T.S., A.J.H.M.H.), Maastricht University Medical Center (MUMC+), the Netherlands.

The etiology of late-life depression (LLD) is still poorly understood. Microvascular dysfunction (MVD) has been suggested to play a role in the etiology of LLD, but direct evidence of this association is scarce. The aim of this study was to investigate whether direct and indirect markers of early microvascular dysfunction are associated with prevalent and incident LLD in the population-based Maastricht Study cohort. Read More

Circ Cardiovasc Interv 2020 06 10;13(6):e009019. Epub 2020 Jun 10.

School of Cardiovascular Medicine and Sciences, British Heart Foundation Centre of Excellence and National Institute for Health Research Biomedical Research Centre (H.R., O.M.D., M.R., H.M., H.E., A.W., D.P.), King's College London, United Kingdom.

Background: Among patients with angina and nonobstructive coronary artery disease, those with coronary microvascular dysfunction have a poor outcome. Coronary microvascular dysfunction is usually diagnosed by assessing flow reserve with an endothelium-independent vasodilator like adenosine, but the optimal diagnostic threshold is unclear. Furthermore, the incremental value of testing endothelial function has never been assessed before. Read More

Sci Signal 2020 06 2;13(634). Epub 2020 Jun 2.

Diabetes and Cardiovascular Research, Sanofi US Services, 55 Corporate Drive, Bridgewater, NJ 08807, USA.

Endothelial dysfunction is a hallmark of tissue injury and is believed to initiate the development of vascular diseases. Sphingosine-1 phosphate receptor-1 (S1P) plays fundamental physiological roles in endothelial function and lymphocyte homing. Currently available clinical molecules that target this receptor are desensitizing and are essentially S1P functional antagonists that cause lymphopenia. Read More

J Am Coll Cardiol 2020 05;75(20):2538-2549

British Heart Foundation Centre of Excellence and National Institute for Health Research Biomedical Research Centre at the School of Cardiovascular Medicine and Sciences, Kings College London, London, United Kingdom. Electronic address:

Background: Coronary microvascular dysfunction (CMD) is defined by diminished flow reserve. Functional and structural CMD endotypes have recently been described, with normal and elevated minimal microvascular resistance, respectively.

Objectives: This study determined the mechanism of altered resting and maximal flow in CMD endotypes. Read More

Catheter Cardiovasc Interv 2020 05;95(6):1102-1103

Department of Cardiovascular Medicine, Beaumont Hospital, Royal Oak, Michigan, USA.

Invasive pressure measurements using hyperemic fractional flow reserve (FFR) and nonhyperemic pressure measurements (NHPR) are superior to angiography alone for assessment of 50-90% stenoses. FFR devices using piezoelectric and optical sensors achieve 94% concordance in FFR values; microcatheter designs have more lesion-crossing failures and less pressure drift compared with guidewire designs. Despite the similarity in statistical performance among FFR devices, interventional cardiologists may prefer to use NHPR to avoid the need for adenosine-related side effects, variations in vasodilator response, and limited application in patients with certain clinical and anatomic features. Read More

J Am Heart Assoc 2020 05 15;9(10):e015507. Epub 2020 May 15.

Regional Cardiocerebrovascular Center Dong-A University Hospital Busan South Korea.

Background This study investigated whether the microvascular dysfunction differed between culprit and non-culprit vessels in patients with acute coronary syndrome who underwent percutaneous coronary intervention. Methods and Results In 115 prospectively recruited patients, after successful percutaneous coronary intervention, culprit and non-culprit intracoronary hemodynamic measurements were performed and repeated at 6-month follow-up. N-ammonia positron emission tomography was performed at 6-month follow-up visit to determine absolute myocardial blood flow. Read More

Cells 2020 05 12;9(5). Epub 2020 May 12.

Department of Physiology, Jagiellonian University Medical College, 31-531 Cracow, Poland.

Exposure to acidic gastric content due to malfunction of lower esophageal sphincter leads to acute reflux esophagitis (RE) leading to disruption of esophageal epithelial cells. Carbon monoxide (CO) produced by heme oxygenase (HMOX) activity or released from its donor, tricarbonyldichlororuthenium (II) dimer (CORM-2) was reported to protect gastric mucosa against acid-dependent non-steroidal anti-inflammatory drug-induced damage. Thus, we aimed to investigate if CO affects RE-induced esophageal epithelium lesions development. Read More

J Aging Res 2020 7;2020:4602067. Epub 2020 Jan 7.

The Witelon State University of Applied Sciences in Legnica, Faculty of Health Science and Physical Education, Legnica, Poland.

Materials And Methods: In the study, 48 men took part with a stabilized and pharmacologically controlled ischaemic disease. The participants were randomly divided into two groups with 24 people in each of them. The research group participated in an aerobic march training. Read More

Ann Intensive Care 2020 May 11;10(1):54. Epub 2020 May 11.

Critical Care Department, Parc Taulí Hospital Universitari. Institut d'Investigació i Innovació Parc Taulí (I3PT), Parc Taulí, 1, 08208, Sabadell, Spain.

Background: Weaning from mechanical ventilation (MV) is a cardiovascular stress test. Monitoring the regional oxygenation status has shown promising results in predicting the tolerance to spontaneously breathe in the process of weaning from MV. Our aim was to determine whether changes in skeletal muscle oxygen saturation (StO) measured by near-infrared spectroscopy (NIRS) on the thenar eminence during a vascular occlusion test (VOT) can be used to predict extubation failure from mechanical ventilation. Read More

Heart Vessels 2020 Oct 4;35(10):1349-1359. Epub 2020 May 4.

Department of Translational Medicine, Eastern Piedmont University, Novara, Italy.

Fractional flow reserve (FFR) assessed during adenosine-induced maximal hyperemia has emerged as a useful tool for the guidance of percutaneous coronary interventions (PCI). However, interindividual variability in the response to adenosine has been claimed as a major limitation to the use of adenosine for the measurement of FFR, carrying the risk of underestimating the severity of coronary stenoses, with potential negative prognostic consequences. Genetic variants of the adenosine receptor A2a (ADORA2A gene), located in the coronary circulation, have been involved in the modulation of the hyperemic response to adenosine. Read More