Próba Valsavy zwiększa czułość składowej przywspółczulnej odruchu spowodowanego odbarczeniem baroreceptorów u młodych zdrowych osób

Introduction. The objective was to verify the hypothesis that change in cardiovagal baroreceptor unload reflex sensitivity occurs between early phase 2 (VM2E) and phase 3 (VM3) of the Valsalva manoeuvre (VM). The study was performed on 29 volunteers between the ages of 25 and 40 (29.3 ± SE 4.0). Material and methods. The experimental scheme was as follows: rest in sitting position, VM in sitting position maintaining an expiratory pressure of 20 mm Hg for 15 seconds, rest in sitting position. Changes in systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) were measured using Finapres. Results. In VM2E and VM3, HR increased (+51.76 ± SE 4.06 beats/min., p < 0.001; +37.77 ± SE 8.65 beats/min., p < 0.0001, respectively) in response to a fall in SBP (–47.55 ± SE 3.95 mmHg, p < 0.001; –29.66 ± SE 2.80 mmHg, p < 0.0001; respectively). Both events of baroreceptor unload have been observed within the very similar range of SBP and HR. Conclusion. The slope of regression relating change in heart rate (DHR) and systolic arterial pressure (DSBP) was significantly higher in VM3 (DHR2 = –1.063 × DSBP2 + 7.0986) than in VM2E (DHR1 = –0.4395 × DSBP2 + 30.862), suggesting the increased baroreceptors’ sensitivity toward SBP fall in VM3 compared to VM2E. VM increases vagal baroreceptor unloads reflex sensitivity.Wstep. Celem badania było zweryfikowanie hipotezy, że zmiana czułości składowej kardiowagalnej odruchu z baroreceptorów występuje między wczesną fazą 2 (VM2E) a fazą 3 (VM3) próby Valsalvy (VM, Valsalva manoeuvre). Materiał i metody. Badanie przeprowadzono w grupie 29 ochotników w wieku 25–40 lat (29,3 ± błąd standardowy średniej [SE, standard error of the mean] 4,0). Eksperyment przeprowadzono według następującego schematu: odpoczynek w pozycji siedzącej, VM w pozycji siedzącej, utrzymując ciśnienie wydechowe na poziomie 20 mm Hg przez 15 sekund, odpoczynek w pozycji siedzącej. Za pomocą urządzenia Finapres zmierzono zmiany wartości skurczowego ciśnienia tętniczego (SBP, systolic blood pressure), rozkurczowego ciśnienia tętniczego (DBP, diastolic blood pressure) i częstotliwości rytmu serca (HR, heart rate). Wyniki. W trakcie faz VM2E i VM3 nastąpiło zwiększenie HR (odpowiednio +51,76 ± SE 4,06 uderzeń/min; p < 0,001 i +37,77 ± SE 8,5 uderzeń/min; p < 0,0001) w odpowiedzi na zmniejszenie SBP (odpowiednio –47,55 ± SE 3,95 mm Hg; p < 0,001 i –29,66 ± SE 2,80 mm Hg; p < 0,0001). W obu przypadkach odbarczenie baroreceptorów obserwowano w bardzo podobnym zakresie SBP i HR. Wnioski. Nachylenie linii regresji odnoszących się do zmiany częstotliwości rytmu serca (DHR) i skurczowego ciśnienia tętniczego (DSBP) było istotnie większe w fazie VM3 (DHR2 = –1,063 × DSBP2 + 7,0986) niż w fazie VM2E (DHR1 = –0,4395 × DSBP2 + 30,862), co wskazuje na zwiększenie czułości baroreceptorów w stosunku do spadku SBP w fazie VM3 w porównaniu z fazą VM2E. VM zwiększa czułość składowej przywspółczulnej odruchu wywołany odbarczeniem baroreceptorów

Morphometric evaluation of the delayed cerebral arteries response to acetazolamide test in patients with chronic carotid artery stenosis using computed tomography angiography

Background: The evidence accumulates that the response to acetazolamide test is delayed on the ipsilateral side to stenosis. However, the effect of acetazolamide beyond 30 min after acetazolamide administration remains unknown. The aim of this study was to assess the diameters of anterior cerebral arteries (ACAs), middle cerebral arteries (MCAs) and posterior cerebral arteries (PCAs) before and 60 min after the acetazolamide test. Materials and methods: Seventeen patients with carotid artery stenosis ≥ 90% on the ipsilateral side and ≤ 50% on the contralateral side were enrolled into the study. Diagnosis was based on ultrasonography examination and was confirmed using digital subtractive angiography. In all patients, two computed tomography angiography examinations were carried out; the first was performed before the acetazolamide administration, while the second one was carried out 60 min after injections. Results: In response to the acetazolamide test: PCA diameter diminished in both ipsi- and contra-lateral side to stenosis (from 1.31 to 1.24 mm and from 1.23 to 1.15 mm, respectively), ACA and MCA decreased in the contralateral side to the stenosis (from 1.33 to 1.26 mm and from 2.75 to 2.66 mm, respectively), ACA and MCA increased in the ipsilateral side to the stenosis (from 1.29 to 1.46 mm and from 2.77 to 2.96 mm, respectively). All changes were statistically significant. Conclusions: There were significant differences in reactivity to acetazolamide challenge between the internal carotid artery (ICA) and vertebrobasilar circulation in patients suffering from chronic carotid artery stenosis. Within the ICA territory, ACA and MCA responses vary in the affected and not affected side.

Intracranial region of the vertebral artery: morphometric study in the context of clinical usefulness

Background: The aim of this study was to analyse the morphometry of the intracranial segment of the vertebral artery in the context of clinical usefulness. The results were compared with published data available in full-text archived medical journals. Materials and methods: More than 100 digital subtraction angiography (DSA) and 3-dimensional (3D) angio-computed tomography (CT) examinations were used to measure the following parameters: the whole and partial length of V4 in characteristic anatomical points, the diameter in three places (on the level of foramen magnum, in point of exit to the posterior inferior cerebellar artery, and in the vertebro-basilar junction), the angle of connection to the vertebral arteries, and all anatomical variations including fenestration, duplication, dolichoectasia or absent artery. Results: The left V4 section was predominant over the right artery, which is manifested by length, width, cases of ectasia and fewer cases of hypoplasia. The incidences of V4 ectasia were identified more often than those documented in the accessible literature, and they were found in the natural location of formation of saccular aneurysms. Conclusions: The presented knowledge of anatomical variation and abnormali­ties of vertebral circulation can improve the accuracy and “safety” of the surgical procedures in this region, help to determine the range of surgical approach and avoid associated complications. The radiological examinations using 3D CT, DSA reveal unlimited observation of anatomical structures in contrast to studies based on cadavers, and can complement the morphometry in anatomical preparations

Effect of series of periodic limb movements in sleep on blood pressure, heart rate and high frequency heart rate variability

Introduction. The phenomenon known as periodic limb movements in sleep (PLMS) has been linked to a change in autonomic nervous system (ANS) activity and its effect on circulatory regulation. Autonomic dysfunction or dysregulation in patients with PLMS has been described in some domains; however, any relationship between heart rate variability (HRV) and PLMS has not been clearly established. HRV analysis is a recognised, non-invasive research method that describes the influence of the ANS on heart rate (HR). The aim of our study was to further investigate the dysregulation of autonomic HR control in patients with PLMS. Material and methods. We undertook a retrospective analysis of the polysomnographic (PSG), demographic and medical data of five patients with a total number of 1,348 PLMS. We analysed HR, HRV HF, systolic blood pressure (SBP), and diastolic blood pressure (DBP) for 10 heartbeats before the series of PLMS and 10 consecutive heartbeats as beat-to-beat measurements. The presented method of using successive, short, 10 RR interval segments refers to the time-frequency measurement, which is very clear and useful for presenting changes in the calculated parameters over time and thereby illustrating their dynamics. This method allowed us to assess dynamic changes in HRV HF during successive PLMS series. Statistical analysis was performed using IBM SPSS Statistics (v. 28.0.0.0). The Kruskal–Wallis test was performed to find statistically significant changes from baseline. Results. No statistically significant changes in HR, SBP, or DBP were found in our group, although an increase in the value of the HRV HF was noted, suggesting an increase in intracardiac parasympathetic activity during the subsequent series of PLMS. Conclusions. Our study indicates an increase in parasympathetic activity during the appearance of successive PLMS, which, with the simultaneous lack of changes in HR, may suggest an increase in sympathetic activity, and therefore the appearance of so-called ‘autonomic co-activation’ resulting in the possibility of life-threatening cardiac events. Clinical implications. Our findings add to the literature information regarding HRV in PLMS, and highlight the need for further studies to elucidate the effects of these conditions on the ANS, and on cardiovascular health

The importance of microvascular inflammation in ageing and age-related diseases: a position paper from the ESH working group on small arteries, section of microvascular inflammation

Microcirculation is pervasive and orchestrates a profound regulatory cross-talk with the surrounding tissue and organs. Similarly, it is one of the earliest biological systems targeted by environmental stressors and consequently involved in the development and progression of ageing and age-related disease. Microvascular dysfunction, if not targeted, leads to a steady derangement of the phenotype, which cumulates comorbidities and eventually results in a nonrescuable, very high-cardiovascular risk. Along the broad spectrum of pathologies, both shared and distinct molecular pathways and pathophysiological alteration are involved in the disruption of microvascular homeostasis, all pointing to microvascular inflammation as the putative primary culprit. This position paper explores the presence and the detrimental contribution of microvascular inflammation across the whole spectrum of chronic age-related diseases, which characterise the 21st-century healthcare landscape. The manuscript aims to strongly affirm the centrality of microvascular inflammation by recapitulating the current evidence and providing a clear synoptic view of the whole cardiometabolic derangement. Indeed, there is an urgent need for further mechanistic exploration to identify clear, very early or disease-specific molecular targets to provide an effective therapeutic strategy against the otherwise unstoppable rising prevalence of age-related diseases

Subarachnoid Space: New Tricks by an Old Dog

PURPOSE: The purpose of the study was to: (1) evaluate the subarachnoid space (SAS) width and pial artery pulsation in both hemispheres, and (2) directly compare magnetic resonance imaging (MRI) to near-infrared transillumination/backscattering sounding (NIR-T/BSS) measurements of SAS width changes in healthy volunteers. METHODS: The study was performed on three separate groups of volunteers, consisting in total of 62 subjects (33 women and 29 men) aged from 16 to 39 years. SAS width was assessed by MRI and NIR-T/BSS, and pial artery pulsation by NIR-T/BSS. RESULTS: In NIR-T/BSS, the right frontal SAS was 9.1% wider than the left (p<0.01). The SAS was wider in men (p<0.01), while the pial artery pulsation was higher in women (p<0.01). Correlation and regression analysis of SAS width changes between the back- and abdominal-lying positions measured with MRI and NIRT-B/SS demonstrated high interdependence between both methods (r = 0.81, p<0.001). CONCLUSIONS: NIR-T/BSS and MRI were comparable and gave equivalent modalities for the SAS width change measurements. The SAS width and pial artery pulsation results obtained with NIR-T/BSS are consistent with the MRI data in the literature related to sexual dimorphism and morphological asymmetries between the hemispheres. NIR-T/BSS is a potentially cheap and easy-to-use method for early screening in patients with brain tumours, increased intracranial pressures and other abnormalities. Further studies in patients with intracranial pathologies are warranted

Understanding the Physiopathology Behind Axial and Radial Diffusivity Changes—What Do We Know?

The use of the diffusion tensor imaging (DTI) is rapidly growing in the neuroimaging field. Nevertheless, rigorously performed quantitative validation of DTI pathologic metrics remains very limited owing to the difficulty in co-registering quantitative histology findings with magnetic resonance imaging. The aim of this review is to summarize the existing state-of-the-art knowledge with respect to axial (λ║) and radial (λ┴) diffusivity as DTI markers of axonal and myelin damage, respectively. First, we provide technical background for DTI and briefly discuss the specific organization of white matter in bundles of axonal fibers running in parallel; this is the natural target for imaging based on diffusion anisotropy. Second, we discuss the four seminal studies that paved the way for considering axial (λ║) and radial (λ┴) diffusivity as potential in vivo surrogate markers of axonal and myelin damage, respectively. Then, we present difficulties in interpreting axial (λ║) and radial (λ┴) diffusivity in clinical conditions associated with inflammation, edema, and white matter fiber crossing. Finally, future directions are highlighted. In summary, DTI can reveal strategic information with respect to white matter tracts, disconnection mechanisms, and related symptoms. Axial (λ║) and radial (λ┴) diffusivity seem to provide quite consistent information in healthy subjects, and in pathological conditions with limited edema and inflammatory changes. DTI remains one of the most promising non-invasive diagnostic tools in medicine

Liver antioxidant and aerobic status improves after metformin and melatonin administration in a rat model of high-fat diet and mammary carcinogenesis

Oxidative stress is involved in the development of various cancers. In the present study the effect of long-term administration of peroral antidiabetic metformin and pineal hormone melatonin on liver antioxidant and aerobic status in female Sprague-Dawley rats carrying mammary tumors induced by N-methyl-N-nitrosourea was evaluated. Both substances were administered in a preventive/curative manner (12 days before and 16 weeks after the carcinogen application). Carcinogen administration induced oxidative stress: the level of thiobarbituric acid reactive products (TBARS) as a marker of reactive oxygen species (ROS) generation in liver increased as well as the level of oxidatively modified protein content (OMP, aldehyde and ketone derivates). Metformin administration restored succinate dehydrogenase and lactate dehydrogenase activity and associated ROS production and OMP content to the level of intact rats, with predominant activation of superoxide dismutase (SOD) and glutathione reductase (GR). Melatonin alone and in combination with metformin decreased TBARS content too. OMP content decreased in all groups receiving chemoprevention. The rise in total antioxidant capacity after melatonin and particularly metformin and melatonin combination might result from the initiation of anaerobic metabolism and increasing SOD, GR and glutathione peroxidase (GPx) activity. Long-term administration of metformin and melatonin exerts antioxidant properties in liver, especially in combination.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author