Increase In Arterial Pressure Research Articles

Роль ацетилхолиновой системы и ее компонентов в формировании постковидных синдромов (обзор)

According to the latest data, COVID-19 is classified as a respiratory virus. However, it has been proven to cause a significant multi-organ dysfunction. Despite the increase in the effectiveness of treatment tactics, a post-COVID-19 symptom complex has been observed in patients after recovery, manifesting itself as cephalalgia, brain fog, high fever, muscle weakness and a decrease (or increase) in arterial pressure. To describe this condition, a clinical characteristic has been proposed: post-acute COVID-19 syndrome (PACS). Approximately 57 % of patients hospitalized with COVID-19 have symptoms of PACS even one year after initial infection with COVID-19. This pathological condition is being actively studied, but the question of the causes of PACS and its development mechanisms remains open. One of the possible reasons behind this symptomatology, in our opinion, is a disorder of the body’s acetylcholine system and its components. The acetylcholine system plays an integral role in various physiological and pathophysiological processes, such as the regulation of the muscular system, immune and inflammatory reactions, wound healing, as well as the development of cardiovascular, respiratory and other diseases. A key way of translating acetylcholine signals in the body is through the use of neurotransmission via a chemical synapse. Based on current literature data, there is reason to believe that viral invasion can significantly change the functional activity of the vagus nerve by disrupting signal transmission in a synapse. We believe that the hyperimmune response caused by COVID-19 triggers a chain of pathological mechanisms that are associated with disrupted nitric oxide production and imbalance in acetylcholine and its receptors. An understanding of these processes may open up prospects for improving the effectiveness of treatment and rehabilitation of patients with COVID-19.

PREDICTION OF FLUID RESPONSIVENESS WITH CRYSTALLOID MINI-FLUID CHALLENGE IN CRITICALLY ILL PATIENTS

Background: The mini-fluid challenge test is a good predictor and has minimal limitations in determining fluid responsiveness in the critically ill. However, it primarily relies on colloid infusion. The availability of colloids may vary among hospitals in resource-limited countries, and they can be more expensive than crystalloid fluids. Objective: The study aimed to use crystalloids instead of colloids to predict fluid responsiveness. Methods: This study was conducted from August 2022 to February 2023 among patients with shock in the medical ICU to assess fluid responsiveness. Arterial and central venous catheters were used for the intravenous infusion and monitoring. Data were collected during two consecutive crystalloid mini-fluid challenges of 50 mL each in 1 minute, 100 mL in 2 minutes, and a standard fluid challenge of 300 mL over 15 minutes. The objective was to predict a stroke volume index (SVI) increase of > 10%. Diagnostic accuracy was evaluated using the Receiver Operating Characteristic (ROC) curve, and hemodynamic variables in the positive fluid challenge group were compared for different volume expansions. Results: Twenty-nine patients (62% males; median age, 75 years) were included, with 42 fluid challenge test events. Septic shock was the primary condition in 83% of the cases. The 50 mL crystalloid mini-fluid challenge showed an accuracy of 80% with a sensitivity of 69% and specificity of 100% at the cutoff level of SVI > 5%, Area Under ROC (AUROC)=0.79. In comparison, the 100 mL crystalloid mini-fluid challenge demonstrated an accuracy of 85% (sensitivity of 79% and specificity of 100%) at the cutoff level of SVI > 10% (AUROC= 0.89). In the positive fluid challenge group, administration of crystalloids led to a significant increase in mean arterial pressure and SVI, while other parameters remained comparable. Conclusions: A mini-fluid challenge test with 100 mL crystalloids can predict fluid responsiveness in critically ill patients. The best cutoff level was a change in SVI > 10% from baseline.

Adipocyte-Specific Disruption of the BBSome Causes Metabolic and Autonomic Dysfunction.

Obesity is a major public health issue due to its association with type 2 diabetes, hypertension, and other cardiovascular risks. The BBSome, a complex of 8 conserved Bardet-Biedl Syndrome (BBS) proteins, has emerged as a key regulator of energy and glucose homeostasis as well as cardiovascular function. However, the importance of adipocyte BBSome in controlling these physiological processes is not clear. Here, we show that adipocyte-specific constitutive disruption of the BBSome through selective deletion of the Bbs1 gene (AdipoCre/Bbs1fl/fl mice) does not affect body weight under normal chow or high fat & high sucrose diet (HFHSD). However, constitutive BBSome defiency caused impairment in glucose tolerance and insulin sensitivity. Similar phenotypes were observed after inducible adipocyte-specific constitutive disruption of the BBSome (AdipoCreERT2/Bbs1fl/fl mice). Interestingly, a significant increase in renal sympathetic nerve activity, measured using multifiber recording in the conscious state, was observed in AdipoCre/Bbs1fl/fl mice on both chow and HFHSD. A significant increase in tail-cuff arterial pressure was also observed in chow-fed AdipoCre/Bbs1fl/fl mice, but this was not reproduced when arterial pressure was measured by radiotelemetry. Moreover, AdipoCre/Bbs1fl/fl mice had no significant alterations in vascular reactivity. On the other hand, AdipoCre/Bbs1fl/fl mice displayed impaired baroreceptor reflex sensitivity when fed HFHSD, but not on normal chow. Taken together, these data highlight the relevance of the adipocyte BBSome for the regulation of glucose homeostasis, sympathetic traffic. The BBSome also contribute to baroreflex sensitivity under HFHSD, but not normal chow.

Consensus on the procedure of balloon pulmonary angioplasty for chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is classified as group IV pulmonary hypertension, characterized by thrombotic occlusion of the pulmonary arteries leading to vascular stenosis or obstruction, progressive increase in pulmonary vascular resistance and pulmonary arterial pressure, and eventual right heart failure. Unlike other types of pulmonary hypertension, the prognosis of CTEPH can be significantly improved by surgery, vascular intervention, and/or targeted drug therapy. Pulmonary endarterectomy (PEA) is the preferred treatment of choice for CTEPH. However, PEA is an invasive procedure with high operative risks, and is currently only performed in a few centers in China. Balloon pulmonary angioplasty (BPA) is an emerging interventional technique for CTEPH, serving as an alternative for patients who are ineligible for PEA or with residual pulmonary hypertension after PEA. BPA is gaining traction in China, but its widespread adoption is limited due to its complexity, operator skills, and equipment requirements, a lack of standard operating procedures and technical guidance, which limit the further improvement and development of BPA in China. To address this, a multidisciplinary panel of experts was convened to develop the Consensus on the Procedure of Balloon Pulmonary Angioplasty for the Chronic Thromboembolic Pulmonary Hypertension, which fomulates guidelines on BPA procedural qualification, perioperative management, procedural planning, technical approach, and complication prevention, with the aim of providing recommendations and clinical guidance for BPA treatment in CTEPH and standardizing its clinical application in this setting. Summary of recommendations: Recommendation 1: It is recommended that physicians who specialize in pulmonary vascular diseases take the lead in formulating the diagnostic and treatment plans for CTEPH, using a multidisciplinary approach.Recommendation 2: Training in BPA technique is critical; novice operators should undergo standardized operative training with at least 50 procedures under the guidance of experienced physicians before embarking on independent BPA procedures.Recommendation 3: BPA requires catheterization labs, angiography systems, standard vascular interventional devices and consumables, drugs, and emergency equipment.Recommendation 4: Patient selection for BPA should consider cardiac and pulmonary function, coagulation status, and comorbid conditions to determine indications and contraindications, thereby optimizing the timing of the procedure and improving safety.Recommendation 5: In experienced centers, patients deemed likely to benefit from early BPA, based on clinical and imaging features of CTEPH and without elevated D-dimer levels, could bypass standard 3-month anticoagulation therapy.Recommendation 6: BPA is a complex interventional treatment that requires thorough pre-operative assessment and preparation.Recommendation 7: The use of perioperative anticoagulants in BPA requires a comprehensive risk assessment of intraoperative bleeding by the operator for individualized decision making.Recommendation 8: A variety of venous access routes are available for BPA; unless contraindicated, the right femoral vein is usually preferred because of its procedural convenience and reduced radiation exposure.Recommendation 9: For the different types of vascular lesion in CTEPH, treatment of ring-like stenoses, web-like lesions, and subtotal occlusions should be prioritized before addressing complete occlusions and tortuous lesions, in order to reduce complications and improve procedural safety.Recommendation 10: A targeted, incremental balloon dilatation strategy based on vascular lesions is recommended for BPA.Recommendation 11: Intravascular pulmonary artery imaging technologies, such as OCT and IVUS can assist in accurate vessel sizing and confirmation of wire placement in the true vascular lumen. Pressure wires can be used to objectively assess the efficacy of dilatation during BPA.Recommendation 12: Endpoints for BPA treatment should be individually assessed, taking into account improvements in clinical symptoms, hemodynamics, exercise tolerance, and quality of life.Recommendation 13: Post-BPA routine monitoring of vital signs is essential; anticoagulation therapy should be initiated promptly post-procedure in the absence of complications. In cases of intraoperative hemoptysis, postoperative anticoagulation regimen adjustments should be adjusted according to the bleeding severity.Recommendation 14: If reperfusion pulmonary edema occurs during or after BPA, ensure adequate oxygenation, diuresis, and consider non-invasive positive-pressure ventilation if necessary, while severe cases may require early mechanical ventilation assistance or ECMO.Recommendation 15: In cases of intraoperative hemoptysis, temporary balloon occlusion to stop bleeding is recommended, along with protamine to neutralize heparin. Persistent bleeding may warrant the use of gelatin sponges, coil embolization, or covered stent implantation.Recommendation 16: For contrast imaging during BPA, non-ionic, low or iso-osmolar contrast agents are recommended, with hydration status determined by the patient's clinical condition, cardiac and renal function, and intraoperative contrast volume used.

A descending pathway from the lateral/ventrolateral PAG to the rostroventral medulla mediating the vasomotor response evoked by social defeat stress in rats.

The stress-induced cardiovascular response is based upon the defensive reaction in mammals. It has been shown that the sympathetic vasomotor pathway of acute psychological stress is indirectly mediated via neurons in the rostroventral medulla (RVM) from the hypothalamic stress center. In this study, direct projections to the RVM and distribution of neuroexcitatory marker, c-Fos expressed neurons were investigated during social defeat stress (SDS) in conscious rats. The experimental rat that was injected with a neural tracer, FluoroGold (FG) into the unilateral RVM, was exposed to the SDS. Double positive neurons of both c-Fos and FG were locally distributed in the lateral/ventrolateral periaqueductal grey matter (l/vl PAG) in the midbrain. These results suggest that the neurons in the l/vl PAG contribute to the defensive reaction evoked by acute psychological stress, such as the SDS. During the SDS period, arterial pressure (AP) and heart rate (HR) showed sustained increases in the rat. Therefore, we performed chemical stimulation by excitatory amino acid microinjection within the l/vl PAG and measured cardiovascular response and sympathetic nerve activity in some anesthetized rats. The chemical stimulation of neurons in the l/vl PAG caused significant increases in arterial pressure and renal sympathetic nerve activity. Taken together, our results suggest that neurons in the l/vl PAG are a possible candidate for the cardiovascular descending pathway that modulates sympathetic vascular resistance evoked by acute psychological stress, like the SDS.

Deletion of Piezo2 from renal Foxd1+ stromal progenitors and descendent cells results in abnormal mesangial development and sex-specific differences in kidney function

Piezo2 is a mechanically activated ion channel recently identified in glomerular mesangial cells and renin+ juxtaglomerular (JG) cells. Despite several studies which confirm this localization of Piezo2 in the kidney, the function of Piezo2 in these cells remains ambiguous. In the current study, we hypothesized that loss of Piezo2 in mesangial and JG cells would result in abnormal glomerular development during nephrogenesis and impaired salt and water balance in adult mice. To test this hypothesis, we generated mutant mice lacking Piezo2 in Foxd1+ stromal progenitors and their cell lineages, which include mesangial and JG cells. Kidney morphology was assessed by immunofluorescent staining and z-stack confocal microscopy during late nephrogenesis (post-natal day 0, P0) and following maturation of the nephron (P20) in wild-type (Piezo2fl/fl, n=3), heterozygous (Foxd1GC/+Piezo2fl/+, n=3), and mutant (Foxd1GC/+Piezo2fl/fl, n=3) mice. In adult male and female mice (n=2/genotype/sex), blood pressure was measured by tail cuff (CODA Systems) between 1-4pm following 3 days of acclimation. In a separate group of control and mutant male and female mice (8-10 weeks, n=3-5/group/sex), a 4-hour saline challenge (i.p. 10% body weight) was performed to assess diuresis and natriuresis. At P0, we found that deletion of Piezo2 from Foxd1+ stromal progenitors and their cell lineages resulted in the abnormal distribution of mesangial cells within glomeruli, such that the mesangial area appears compressed compared to control or heterozygous mice. This phenotype was exacerbated in mutant mice by P20. In adult mice, female mutants had an increase in daytime mean arterial pressure (~10mmHg, mean 79 vs 88) compared to female controls. Cumulative urine excretion (4 hours, percent injected) was decreased in females compared to males, regardless of genotype (p<0.001). Further, female mutant mice had a delayed diuresis response compared to control (2 hour, mean 16% vs 28% cumulative urine volume). However by 4 hours following a saline bolus both groups were similar. Taken together, these data indicate that deletion of Piezo2 in Foxd1+ stromal progenitors results in impairments in mesangial cell development during nephrogenesis and alterations in water and salt balance in adult female mice. Understanding the sex-specific roles of Piezo2 in kidney development and physiology is critical to identify the role of mechanosensation on renal homeostasis. NIH R01DK121014 to LO. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Estrogen stimulates fetal vascular endothelial growth factor expression and microvascularization.

We recently showed that the ratio of capillaries/myofibers in skeletal muscle, which accounts for 80% of insulin-directed glucose uptake and metabolism, was reduced in baboon fetuses in which estrogen was suppressed by maternal letrozole administration. Since vascular endothelial growth factor (VEGF) promotes angiogenesis, the present study determined the impact of estrogen deprivation on fetal skeletal muscle VEGF expression and capillary development and long-term vascular and metabolic function in 4-8 year old adult offspring. Maternal baboons were untreated or treated with letrozole or letrozole plus estradiol on days 100-164 of gestation (term = 184 days). Skeletal muscle VEGF protein expression was suppressed by 45% (P < 0.05) and correlated (P = 0.01) with a 47% reduction (P < 0.05) in number of capillaries per myofiber area in fetuses of baboons in which serum estradiol levels were suppressed 95% (P < 0.01) by letrozole administration. The reduction in fetal skeletal muscle microvascularization was associated with a 52% decline (P = 0.02) in acetylcholine-induced brachial artery dilation and 23% increase (P = 0.01) in mean arterial blood pressure in adult progeny of letrozole-treated baboons and restored to normal by letrozole plus estradiol. The present study indicates that estrogen upregulates skeletal muscle VEGF expression and systemic microvessel development within the fetus as an essential programming event critical for ontogenesis of systemic vascular function and insulin sensitivity/glucose homeostasis after birth in primate offspring.

Interleukins expression by lymphocytes of rats exposed to chronic intermittent normobaric hypoxia

Hypoxia acute and chronic modulates the expression of inflammatory mediators such as cytokines. However, studies in chronic and intermittent hypobaric or normobaric hypoxia similar to described in miner’s population are scares o absent. In regards with this we propose evaluated the effect of chronic intermittent normobaric hypoxia (CINH) on the hematological, cardiovascular response and expression of lymphocyte’s cytokines such as IL-1b, IL-2, IL6 and IL-10 in rats. A total of 20 Sprague-Dawley rats were divided in two groups: a) CINH of FiO2 10% (n=10) and normoxic rats (n=10) were used as controls. Blood samples were obtained from both groups for hematological studies, systolic arterial pressure and heart rate was measured in tail-cuff sensor, and expression of cytokines obtained from lymphocytes was determined by RT-PCR. Hematocrit, hemoglobin, platelet count and hematological constant are elevated however leucocyte count decrease. A significant increase of systolic arterial pressure (over 50%). In vitro expression of cytokines from lymphocytes shown that IL-10, IL-2 and IL6 increase 35%, 64% and 16% respectively, while that of IL-1bdecreases by 18%. CINH could be activate an inflammatory response mediated by IL-2, however this response could be attenuated due to the increase in the expression of IL-10, a known anti-inflammatory cytokine, and the decrease in the expression of IL-1β and IL6 suggesting a mechanism of adaptation to CINH. Innova-Corfo Project 07CN13ISM-152. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Persistent iatrogenic atrial septal defect after cryoballoon ablation for atrial fibrillation

Aims: Pulmonary vein isolation (PVI) by cryoballoon ablation (CB) technology is effective and safe treatment option for atrial fibrillation (AF). CB is performed by large diameter, 15Fr (4.95mm) transseptal sheath that may lead to creation of iatrogenic atrial septal defect (iASD). The objective of this study was to assess the incidence of iASD in patients who had undergone CB. Methods: Patients with AF having undergone Arctic Front® CB ablation and a subsequent transesophageal echocardiography (TEE) examination during post-ablation follow up period were consecutively enrolled. During all CB procedures, 15Fr transseptal sheath (Flex Cath, Medtronic, Minneapolis, MN) was utilized via single transseptal puncture (TsP). Results: Twenty-eight patients (15 females, mean age 55.8+15.5) with paroxysmal (n=24) or persistent (n=4) AF formed study group. iASD was present 11 (39.3%) of them after mean follow-up time of 17.3+6.2 months. The procedural time is significantly longer in patient with iASD (119.0+8.8 minutes, p=0.01). No patients died or suffered from any clinically significant cerebral ischemic event. There was no sign of increase in systolic pulmonary arterial pressure (sPAP). Conclusion: iASD after CB was found to be present in 39.3% of patient during a mean follow-up time of 17.3+6.2 months. The prolonged CB procedural time was the only factor that predicted iASD in our study. No adverse clinic events that might be related to iASD was observed during follow-up period.

Management of Pregnant Women with Atrial Septal Defect and Pulmonary Hypertension: A Case Report

Background: Pulmonary Hypertension (PH) is a condition where there is an increase in Pulmonary Vascular Resistance (PVR) and an increase in the mean Pulmonary Arterial Pressure (mPAP) to more than 20 mmHg. PH can occur in someone with Congenital Heart Disease (CHD). PH conditions can aggravate pregnancy in women with CHD. Women with PH are recommended not to undergo pregnancy. However, it is possible for women with CHD with PH conditions to undergo pregnancy. In these conditions, optimizing PH therapy is essential so that pregnant women with PH do not experience a worsening of the condition and can carry out their pregnancy well until delivery. Case presentation: A 38-year-old female patient with a history of Atrial Septal Defect-Pulmonary Hypertension came for common control to the cardiac clinic with the pregnancy condition of her 4th child, who was just discovered when she was six months pregnant. Since giving birth to her third child, the patient began complaining of being quickly tired when doing activities accompanied by swollen legs that disappeared with rest. The patient went to a cardiologist for an echocardiography examination and was diagnosed with Atrial Septal Defect (ASD)-Pulmonary Hypertension (PH). Since then, the patient has been routinely treated by a cardiologist with Pulmonary Hypertension drugs, including Phospodiesterase5 (PDE5) inhibitors (Sildenafil) and Prostacyclin Analogue (Dorner). The patient had done Transesophageal Echocardiography (TEE) with the results of ASD secundum suitable for closure by the device. Patients with Right Heart Catheterization (RHC) results, ASD secundum with PH High Flow High Resistance reactive to Vasoreactivity Test. Since the patient was found to be pregnant, the patient continued to use Sildenafil and discontinued the use of Dorner. The patient then continued treatment in a multidisciplinary team. Conclusion: Management of pregnant women with CHD and PH is essential because the condition of PH itself further aggravates the condition of pregnancy. Medical management for PH in pregnant women follows the guidelines for the safety of drugs in pregnancy so that the choice of therapy is crucially related to the goal of treatment to control the PH condition in the patient but still pay attention to safety in pregnancy conditions. Keyword: Congenital Heart Disease, Phosphodiesterase-5 (PDE-5)- Inhibitor, Prostacyclin Analogue, Pulmonary Hypertension.

Clinical Features and Multimodality Diagnostic Tools of Pulmonary Hypertension

Pulmonary hypertension (PH) is defined as an increase in mean pulmonary arterial pressure (mPAP) above normal (&gt; 20 mmHg) and an increase in pulmonary vascular resistance (pulmonary vascular resistance / PVR) above normal in resting settings. The pathophysiology of PH involves remodeling of the pulmonary vessels, from the main pulmonary arteries, lobar arteries, segmental arteries, distal arteries, pulmonary arterioles, capillaries to the postcapillary pulmonary veins. In general, the epidemiological figures for PH are not known with certainty. The United Kingdom reported a PH prevalence of 97 cases per one million people, with a female-to-male ratio of 1.8. The diagnostic strategy for PH focuses primarily on two issues. The primary objective is to improve the early detection of PH and expedite the transfer of patients at high risk for PAH, CTEPH, or other forms of severe PH to a PH center. The second objective is to identify the underlying disease, including left heart disease (Group 2 PH) and lung disease (Group 3 PH), as well as comorbidities, in order to assure proper classification, risk assessment, and therapy. The gold standard for detecting and categorizing pulmonary hypertension is right heart catheterization (RHC). Clinical scoring in the form of shortness of breath without any obvious cause accompanied by physical examination, ECG and Thorax X-ray images which depict an enlarged right heart have good specificity and sensitivity for the diagnosis of pulmonary hypertension in patients with congenital heart disease. A high right ventricular pressure, mean PAP, and BNP values during observation, as well as heart size on chest X-ray can be predictors of a poorer prognosis in this population. Keyword: Clinical Risk Scoring, Pulmonary Hypertension, Right Heart Catheterization.

A mathematical model to assess the effects of COVID-19 on the cardiocirculatory system

Impaired cardiac function has been described as a frequent complication of COVID-19-related pneumonia. To investigate possible underlying mechanisms, we represented the cardiovascular system by means of a lumped-parameter 0D mathematical model. The model was calibrated using clinical data, recorded in 58 patients hospitalized for COVID-19-related pneumonia, to make it patient-specific and to compute model outputs of clinical interest related to the cardiocirculatory system. We assessed, for each patient with a successful calibration, the statistical reliability of model outputs estimating the uncertainty intervals. Then, we performed a statistical analysis to compare healthy ranges and mean values (over patients) of reliable model outputs to determine which were significantly altered in COVID-19-related pneumonia. Our results showed significant increases in right ventricular systolic pressure, diastolic and mean pulmonary arterial pressure, and capillary wedge pressure. Instead, physical quantities related to the systemic circulation were not significantly altered. Remarkably, statistical analyses made on raw clinical data, without the support of a mathematical model, were unable to detect the effects of COVID-19-related pneumonia in pulmonary circulation, thus suggesting that the use of a calibrated 0D mathematical model to describe the cardiocirculatory system is an effective tool to investigate the impairments of the cardiocirculatory system associated with COVID-19.

Evaluation of the inter-arm blood pressure difference in subjects with hypertension in Nnewi North Local Government Area, Anambra state

Hypertension is defined as a sustained elevated blood pressure with a systolic blood pressure (SBP) of 140mmHg or more and a diastolic blood pressure of 90mmHg or more. The evaluation of the inter-arm blood pressure difference in subjects with hypertension in Nnewi North Local Government Area, Anambra state was done via sampling techniques. The study population was obtained using convenience sampling method and comprised of male and female hypertensive patients aged 25 to 90 years, from the cardiology unit NAUTH Nnewi. Normotensive subjects of the same age range and gender were used as control. The sample size was determined to be 70 subjects using this formula: n= (z2pq)/d2). The result of the finding showed that there was a significant increase in the mean age when the control was compared to the hypertensive group, and no significant difference in their weight, height and BMI. Furthermore, the findings of this research also supported a significant increase in the left arterial systolic and diastolic blood pressure in the control compared to the hypertensive groups. Also, the mean right systolic and diastolic blood pressure showed a significant increase when the control was compared to the hypertensive group. The inter-arm systolic and diastolic blood pressure had no significant difference when control was compared to the hypertensive group.

Estimation of Systolic and Diastolic Blood Pressure for Hypertension Identification from Photoplethysmography Signals

Continuous monitoring plays a crucial role in diagnosing hypertension, characterized by the increase in Arterial Blood Pressure (ABP). The gold-standard method for obtaining ABP involves the uncomfortable and invasive technique of cannulation. Conversely, ABP can be acquired non-invasively by using Photoplethysmography (PPG). This non-invasive approach offers the advantage of continuous BP monitoring outside a hospital setting and can be implemented in cost-effective wearable devices. PPG and ABP signals differ in scale values, which creates a non-linear relationship, opening avenues for the utilization of algorithms capable of detecting non-linear associations. In this study, we introduce Neural Model of Blood Pressure (NeuBP), which estimates systolic and diastolic values from PPG signals. The problem is treated as a binary classification task, distinguishing between Normotensive and Hypertensive categories. Furthermore, our research investigates NeuBP’s performance in classifying different BP categories, including Normotensive, Prehypertensive, Grade 1 Hypertensive, and Grade 2 Hypertensive cases. We evaluate our proposed method by using data from the publicly available MIMIC-III database. The experimental results demonstrate that NeuBP achieves results comparable to more complex models with fewer parameters. The mean absolute errors for systolic and diastolic values are 5.02 mmHg and 3.11 mmHg, respectively.

Analysis of haemodynamics surrounding blood transfusions after the arterial switch operation: a pilot study utilising real-time telemetry high-frequency data capture.

Packed red blood cell transfusions occur frequently after congenital heart surgery to augment haemodynamics, with limited understanding of efficacy. The goal of this study was to analyse the hemodynamic response to packed red blood cell transfusions in a single cohort, as "proof-of-concept" utilising high-frequency data capture of real-time telemetry monitoring. Retrospective review of patients after the arterial switch operation receiving packed red blood cell transfusions from 15 July 2020 to 15 July 2021. Hemodynamic parameters were collected from a high-frequency data capture system (SickbayTM) continuously recording vital signs from bedside monitors and analysed in 5-minute intervals up to 6 hours before, 4 hours during, and 6 hours after packed red blood cell transfusions-up to 57,600 vital signs per packed red blood cell transfusions. Variables related to oxygen balance included blood gas co-oximetry, lactate levels, near-infrared spectroscopy, and ventilator settings. Analgesic, sedative, and vasoactive infusions were also collected. Six patients, at 8.5[IQR:5-22] days old and weighing 3.1[IQR:2.8-3.2]kg, received transfusions following the arterial switch operation. There were 10 packed red blood cell transfusions administered with a median dose of 10[IQR:10-15]mL/kg over 169[IQR:110-190]min; at median post-operative hour 36[IQR:10-40]. Significant increases in systolic and mean arterial blood pressures by 5-12.5% at 3 hours after packed red blood cell transfusions were observed, while renal near-infrared spectroscopy increased by 6.2% post-transfusion. No significant changes in ventilation, vasoactive support, or laboratory values related to oxygen balance were observed. Packed red blood cell transfusions given after the arterial switch operation increased arterial blood pressure by 5-12.5% for 3 hours and renal near-infrared spectroscopy by 6.2%. High-frequency data capture systems can be leveraged to provide novel insights into the hemodynamic response to commonly used therapies such as packed red blood cell transfusions after paediatric cardiac surgery.

Double-Balloon Catheter–Mediated Transarterial Chemotherapy Delivery in a Swine Model: A Mechanism Recruiting the Vasa Vasorum for Localized Therapies

Treatment of hypovascular tumors, such as pancreatic adenocarcinoma, is challenging owing to inefficient drug delivery. This report examines the potential mechanism of localized drug delivery via transarterial microperfusion (TAMP) using a proprietary adjustable double-balloon occlusion catheter in a porcine model. Adult Yorkshire swine (N = 21) were used in the Institutional Animal Care & Use Committee–approved protocols. The RC-120 catheter (RenovoRx, Los Altos, California) was positioned into visceral, femoral, and pulmonary arteries with infusion of methylene blue dye, gemcitabine, or gold nanoparticles. Transmural delivery was compared under double-balloon occlusion with and without side-branch exclusion, single-balloon occlusion, and intravenous delivery. Intra-arterial pressure and vascular histologic changes were assessed. Infusion with double-balloon occlusion and side-branch exclusion provided increased intra-arterial pressure in the isolated segment and enhanced perivascular infusate penetration with minimal vascular injury. Infusates were predominantly found in the vasa vasorum by electron microscopy. TAMP enhanced transmural passage mediated by localized increase in arterial pressure via vasa vasorum.

A proof-of-concept study evaluating cardiac compression techniques for cardiopulmonary resuscitation in laying hens (Gallus gallus).

To determine in adult chickens which of 3 CPR techniques, sternal compressions (SC), SC with interposed caudal coelomic compressions (ICCC), or lateral compressions (LC), results in the highest mean systolic (SAP), diastolic (DAP), and mean arterial pressure (MAP) as measured directly from the carotid artery. Prospective, nonblinded, experimental crossover study. University teaching hospital laboratory. Ten retired laying hens. Birds were sedated, anesthetized, and placed in dorsal recumbency. A carotid artery catheter was placed to directly measure arterial pressure. Ventricular fibrillation was induced with direct cardiac stimulation using a 9-Volt battery. Each bird then received 2minutes of the 3 different cardiac compression techniques in a random order by 3 different compressors, with the compressor order also randomized. Birds were subsequently administered IV epinephrine, and transthoracic defibrillation was attempted. At the end of experimentation, each bird was euthanized, and simple gross necropsies were performed. Linear mixed models followed by pairwise paired t-tests were performed to evaluate differences in pressures generated by each technique. The primary study outcomes were SAP, DAP, and MAP over 2minutes of compressions for each compression technique. Pressures from ICCC (SAP: 27.6±5.3mmHg, DAP: 18.7±5.2mmHg, MAP: 21.7±5.2mmHg) were significantly higher than those from LC (SAP: 18.9±5.4mmHg, DAP: 11.6±4.1mmHg, MAP: 14.1±4.5mmHg). Pressures from SC (SAP: 24.5±6.4mmHg, DAP: 15.2±4.3mmHg, MAP: 18.3±5.0mmHg) were not significantly different from ICCC or LC. External compressions can generate detectable increases in arterial pressure in chickens with ventricular fibrillation. SC with ICCC generated significantly higher arterial pressures than LC. SC alone generated blood pressures that were not significantly different from those generated by SC with ICCC or LC.

Evaluation of Electrocardiogram Parameters and Heart Rate Variability During Blood Pressure Elevation by Phenylephrine in Cirrhotic Rats.

Cirrhotic cardiomyopathy is a myocardial disease that may go undetected in the early stages due to peripheral vasodilatation. The aim of the study was to evaluate the electrocardiogram (ECG) and heart rate variability (HRV) after raising blood pressure by phenylephrine injection in rats with liver cirrhosis. Twenty male Sprague-Dawley rats were divided into the Sham and common bile duct ligation (CBDL) groups. After 44days, animals were anesthetized and the right femoral artery and vein catheterized. After a steady-state period, a bolus injection of phenylephrine (PHE, 10μg/μl/IV, baroreflex maneuver) was followed by a slow injection of PHE (100μg/ml/5min/IV, sustained maneuver). Rapid and slow injections of PHE resulted in a greater increase in mean arterial pressure (MAP) and a weaker bradycardia response in the CBDL group than in the Sham group. ECG analysis showed increased QT, QTc, JT, and T peak to T end in the CBDL group, which remained unchanged after PHE injection. On the other hand, the parasympathetic indices of the HF band and RMSSD, and the sympathetic index of the LF band after PHE injection were lower in the CBDL group than in the Sham group.ECG data indicated prolonged ventricular depolarization and repolarization, independent of blood pressure levels in cirrhosis. On the other hand, after PHE injection, the parasympathetic and sympathetic components of HRV decreased, regardless of the duration of elevated blood pressure. We suggest that HRV analysis can provide a useful approach to assess cardiac dysfunction associated with elevated blood pressure in cirrhosis.

Up-regulated expression of two-pore domain K+ channels, KCNK1 and KCNK2, is involved in the proliferation and migration of pulmonary arterial smooth muscle cells in pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) is a severe and rare disease in the cardiopulmonary system. Its pathogenesis involves vascular remodeling of the pulmonary artery, which results in progressive increases in pulmonary arterial pressure. Chronically increased pulmonary arterial pressure causes right ventricular hypertrophy and subsequent right heart failure. Pulmonary vascular remodeling is attributed to the excessive proliferation and migration of pulmonary arterial smooth muscle cells (PASMCs), which are induced by enhanced Ca2+ signaling following the up-/down-regulation of ion channel expression. In the present study, the functional expression of two-pore domain potassium KCNK channels was investigated in PASMCs from idiopathic PAH (IPAH) patients and experimental pulmonary hypertensive (PH) animals. In IPAH-PASMCs, the expression of KCNK1/TWIK1 and KCNK2/TREK1 channels was up-regulated, whereas that of KCNK3/TASK1 and KCNK6/TWIK2 channels was down-regulated. The similar up-regulated expression of KCNK1 and KCNK2 channels was observed in the pulmonary arterial smooth muscles of monocrotaline-induced PH rats, Sugen 5416/hypoxia-induced PH rats, and hypoxia-induced PH mice. The facilitated proliferation of IPAH-PASMCs was suppressed by the KCNK channel blockers, quinine and tetrapentylammonium. The migration of IPAH-PASMCs was also suppressed by these channel blockers. Furthermore, increases in the proliferation and migration were inhibited by the siRNA knockdown of KCNK1 or KCNK2 channels. The siRNA knockdown also caused membrane depolarization and subsequent decrease in cytosolic [Ca2+]. The phosphorylated level of c-Jun N-terminal kinase (JNK) was elevated in IPAH-PASMCs compared to normal-PASMCs. The increased phosphorylation was significantly reduced by the siRNA knockdown of KCNK1 or KCNK2 channels. Collectively, these findings indicate that the up-regulated expression of KCNK1 and KCNK2 channels facilitates the proliferation and migration of PASMCs via enhanced Ca2+ signaling and JNK signaling pathway, which is associated with vascular remodeling in PAH.

Complement-mediated dialysis reaction during regular hemodialysis treatment: a case report

BackgroundHemodialysis reactions (HDRs) are similar to complement activation-related pseudo allergy (CARPA), a hypersensitivity reaction that occurs when administering certain (nano)drugs intravenously. The pathomechanism of CARPA was described based on animal experiments. Typical CARPA-like dialysis reactions, which occur at the start of hemodialysis, have been reported using polysulfone dialyzers. However, to our knowledge, this is the first dialysis reaction that occurred towards the end of hemodialysis treatment.Case presentationThis report describes a 52-year-old Caucasian male patient who had been receiving chronic hemodialysis for 3 years and exhibited a CARPA reaction during his third hour of treatment. Upon activation of the microbubble alarm, the extracorporeal system recirculated for five minutes. Following reconnection, the patient exhibited a drop in systemic blood pressure, chest pain, and dyspnea after five minutes. Symptoms disappeared spontaneously after reducing the speed of the blood pump, placing the patient in a Trendelenburg position, and administering a bolus infusion from the dialysis machine. The remaining dialysis treatment was uneventful.ConclusionNumerous case reports about reactions occurring with modern high-efficiency polysulfone dialyzers have been published. However, due to changes in the material structure by the manufacturers, we have not encountered such cases lately. The recently reported increase in thromboxane-B2 and pulmonary arterial pressure and complement activation upon re-infusion of extracorporeal blood following dialysis may explain the reaction observed here.