Hemodynamic Alterations Research Articles

Cerebral blood flow and neurocognition in patients undergoing transcatheter aortic valve replacement for severe aortic stenosis.

Aortic valve stenosis (AS) results in higher systolic pressure to overcome resistance from the stenotic valve, leading to heart failure and decline in cardiac output. There has been no assessment of cerebral blood flow (CBF) association with neurocognition in AS or the effects of valve replacement. The goal was to determine if AS is associated with altered cerebral haemodynamics and impaired neurocognition, and whether transcatheter aortic valve replacement (TAVR) improves haemodynamics and cognition. In 42 patients with planned TAVR, transcranial Doppler (TCD) assessed bilateral middle cerebral artery (MCA) mean flow velocities (MFVs); abnormality was <34.45 cm/s. The neurocognitive battery assessed memory, language, attention, visual-spatial skills, and executive function, yielding a composite Z-score. Impairment was <1.5 SDs below the normative mean. The mean age was 78 years, 59% Male, and the mean valve gradient was 46.87 mm/Hg. Mean follow-up was 36 days post-TAVR (range 27-55). Pre-TAVR, the mean MFV was 42.36 cm/s (SD = 10.17), and the mean cognitive Z-score was -0.22 SDs (range -1.99 to 1.08) below the normative mean. Among the 34 patients who returned after TAVR, the MFV was 41.59 cm/s (SD = 10.42), not different from baseline (P = 0.66, 2.28-3.67). Post-TAVR, average Z-scores were 0.17 SDs above the normative mean, not meeting the pre-specified threshold for a clinically significant 0.5 SD change. Among patients with severe AS, there was little impairment of MFV on TCD and no correlation with cognition. Transcatheter aortic valve replacement did not affect MFV or cognition. Assumptions about diminished CBF and improvement after TAVR were not supported.

Ongoing Geometric Remodeling of the Parent Artery After Flow-Diverter Stent Reconstruction in Cerebral Aneurysms: The Device Design Matters

Configuration changes of the parent artery (PA) after flow-diverter (FD) stent reconstruction, caused by the bending force of the device, may have an additional role in aneurysm occlusion as a result of the secondary alteration of intra-aneurysmal hemodynamics related to the geometry alteration of the vessel. To determine the degree of PA deformation and aneurysm occlusion rates after deployment of 2 different types of FD. Patients treated with 2 different designs of cobalt-chromium braid (48 and 64 wire braid) structure FD were subject to analysis. Vascular angle changes at the level of the reconstructed segment immediately after FD deployment and at 1 year follow-up were measured and the potential relationship with aneurysmal occlusion rate was analyzed. Forty-two patients harboring 48 aneurysms were included in the present study. The aneurysms were divided into side wall (85.4%) and bifurcation types (14.6%). Twenty-six aneurysms were treated using the Pipeline FD (48 wire braid; 54.2%) and 22 using the Evolve FD (64 wire braid; 45.8%). Of the 48 aneurysms, 42 (87.5%) met the primary end point of complete occlusion at 12 months. The median postdeployment angle change was 7.04°± 4.59° for the Pipeline and 5.05°± 2.49° for the Evolve, whereas the median 12 months follow-up angle change was 15.49°± 10.99° and 10.01°± 8.83°, respectively. PA angle changes were significantly higher in the bifurcation group compared with the side wall group both during procedure and at 12 months follow-up. Angle change had a statistically nonsignificant association with complete aneurysm occlusion. PA deformation starts immediately after deployment and remodeling continues for 1 year after. Aneurysms located in the vessel bifurcation were more prone to PA straightening after FD deployment than were side wall aneurysms. Furthermore, Pipeline seemed to be more prone to inducing vascular deformation, compared with Evolve.

Patient reported outcome measures (PROMS) and patient reported experience measures (PREMS): Measuring outcomes in pelvic venous disorders

Pelvic venous disorders (PeVD) present with a range of heterogenous symptoms that arise from altered venous hemodynamics in the pelvis. Many of these symptoms lead to mental health and quality of life issues and are not limited to the pelvic region. The nutcracker phenomenon causing left renal vein compression and left ovarian venous hypertension as well as the compression of the left common iliac vein by the overlying right common iliac artery are often stated as the common underlying pathologies. As a result, there has been a sudden increase in the number of ovarian vein coil embolizations and iliac vein stents placed. In truth however, the altered venous hemodynamics in PeVD is more complex. There appears to be little correlation between the symptoms patients experience and the obvious image detected anatomical lesions being treated. In addition, these anatomical lesions are very commonly seen in asymptomatic and especially muti-parous women as well. To compare outcomes of these and other more extensive procedures being performed for these commonly seen anatomical changes in the pelvic veins, objective assessments of the outcomes as seen from the symptom relief they bring to patients treated is essential. Validated Patient-reported outcome measures (PROMS) can be an important tool to compare outcomes across interventions for PeVD. However, as the impact of similar symptoms on different patients’ quality of life (QoL) can vary, developing a validated PROM that can be used to compare procedural outcomes in PeVD is a challenge. On the other hand, complications and procedural success as reported by physician do not assess the effect on a patient’s QoL. This paper provides a narrative review of PROMs, patient reported experience measures (PREMs) and individualized-PROMs. It also suggests a process for how a validated PROM for comparing procedural outcomes in PeVD may be developed. This could provide a framework that incorporates the recently adopted Symptoms-Varices-Pathophysiology (SVP) classification of pelvic venous disorders into the PROM development process to ensure that a like-for-like comparison is made between procedures being performed on a very heterogenous, but long-suffering group of patients.

Crush syndrome-related acute kidney injury in earthquake victims

ABSTRACT Natural disasters are unpredictable and thousands of people are affected yearly. Currently, this risk persists, given the large population living in risk areas prone to suffering another seismic event. Generally, on-site mortality is high and occurs immediately from massive trauma or asphyxia. After surviving the first event, extricated patients are at risk of developing crush syndrome caused by direct physical trauma and compression of the human body with lesions in different tissues. This could lead to several systemic complications, including acute kidney injury (AKI), sepsis, acute respiratory distress syndrome, bleeding, hypovolemic shock, arrhythmias, electrolyte disturbances and disseminated intravascular coagulation. Hence, AKI in this scenario can occur due to many causes, such as rhabdomyolysis, direct renal trauma, hypovolemia and hemodynamic alterations. The most important measure to reduce crush syndrome mortality and prevent the development of crush syndrome-related AKI in disaster situations is the immediate start of treatment. Nevertheless, despite optimal therapy delivery, these previous efforts might not suffice the development and progression of AKI, consequently, the indication of extracorporeal blood purification techniques. This narrative review provides a focused overview of crush syndrome-related AKI, including etiology, mechanisms, diagnosis, current treatment, removal of myoglobin and their limitations.

Analgesic Efficacy of Dexmedetomidine as an Adjuvant to Ropivacaine in Supraclavicular Brachial Plexus Block for Upper Limb Surgeries: A Prospective Randomized Study

Background and Aims: The primary aim of this randomized controlled study was to evaluate the effect of the addition of dexmedetomidine to ropivacaine on the onset and duration of sensory and motor blockade and the duration of analgesia in patients undergoing upper limb surgeries under supraclavicular brachial plexus block. Materials and Methods: A total of 100 patients of age 18–55 years, planned for elective upper limb surgeries under supraclavicular brachial plexus block using a nerve stimulator, were randomly allocated into two groups. Group 1 (n = 50) received 30 mL 0.5% ropivacaine and 1 mL normal saline and Group 2 (n = 50) received 30 mL 0.5% ropivacaine and 1 μg/kg of dexmedetomidine. The onset and duration of sensory and motor block, duration of analgesia, and adverse events during the perioperative period were noted. Results: The onset of sensory and motor block in Group 1 (16. 26 ± 2.23 and 21.68 ± 2.90 min) was slower than those in Group 2 (9.12 ± 2.40 and 12.68 ± 2.62 min), (&lt;0.001). The duration of sensory and motor block in Group 1 was significantly shorter than those in Group 2 (P &lt; 0.001). The duration of analgesia in Group 1 (402.80 ± 28.21 min) was shorter than that in Group 2 (981.00 ± 92.26 min; P &lt; 0.001). There was no statistically significant difference between the two groups in the incidence of the side effects, except in the incidence of sedation which is significantly higher in Group 2, (P &lt; 0.001). Conclusion: Dexmedetomidine with ropivacaine for supraclavicular nerve block resulted in earlier onset and prolonged duration of the sensorimotor blockade and provided a longer pain-free postoperative period without significant hemodynamic alterations.

Different methods for hepatic flow measurements: a narrative review

Hepatic blood flow measurement constitutes an essential tool for successful hepatic surgery, especially in situations where graft patency needs to be controlled, such as for instance during and after liver transplantation. In addition, because of its complex intrinsic regulation, the hepatic circulation may be seriously affected in the perioperative setting not only because of systemic hemodynamic alterations but also secondary to the administration of various drugs including anesthetic agents. Unravelling and understanding such effects implies studies involving measurement of hepatic blood flow. Therefore, knowledge and understanding of various tools for estimation of hepatic blood flow is important for correct interpretation of findings from experimental and clinical studies before potential implementation in daily clinical practice. This review summarizes the different techniques, their strengths and limitations, and potential applications in clinical practice and research.

Exploring the Mechanistic Link Between Obesity and Heart Failure.

Among subtypes of cardiovascular disease, obesity has a potent and unique association with heart failure (HF) that is unexplained by traditional cardiovascular risk mediators. The concomitant rise in the prevalence of obesity and HF necessitates better understanding of their relationship to develop effective prevention and treatment strategies. The purpose of this review is to provide mechanistic insight regarding the link between obesity and HF by elucidating the direct and indirect pathways linking the two conditions. Several direct pathophysiologic mechanisms contribute to HF risk in individuals with excess weight, including hemodynamic alterations, neurohormonal activation, hormonal effects of dysfunctional adipose tissue, ectopic fat deposition with resulting lipotoxicity and microvascular dysfunction. Obesity further predisposes to HF indirectly through causal associations with hypertension, dyslipidemia, and most importantly, diabetes via insulin resistance. Low levels of physical activity and fitness further influence HF risk in the context of obesity. These various processes lead to myocardial injury and cardiac remodeling that are reflected by abnormalities in cardiac biomarkers and cardiac function on myocardial imaging. Understanding and addressing obesity-associated HF is a pressing clinical and public health challenge which can be informed by a deeper understanding of the complex pathways linking these two conditions together.

Presentation of Acute Myocardial Infarction Type 2 in a Patient with Septic Shock

Acute myocardial infarction (MI) in the setting of septic shock presents a multifaceted clinical challenge. In this review, we explore the distinct presentation of type 2 MI among patients grappling with septic shock and coronary artery disease. The coexistence of these conditions poses significant risks, potentially leading to both type 1 and type 2 MIs. We delve into the pathophysiological underpinnings and the clinical implications of these subtypes of MI, emphasizing the altered hemodynamics and increased metabolic demand leading to type 2 MI. Our discussion highlights the differences in management and outcomes, underscoring the critical need for nuanced understanding in clinical practice.

Refining MRI-based criteria for portal vein invasion in hepatocellular carcinoma: improving sensitivity beyond portal vein tumor thrombosis.

To investigate the imaging features indicating portal vein invasion (PVI) of hepatocellular carcinoma (HCC) on gadoxetic acid-enhanced MRI and to create more accurate diagnostic criteria than the presence of portal vein tumor thrombosis (PVTT) on MRI. This retrospective study included patients with surgically resected HCC larger than 5 cm, and the presence of PVI was investigated. On MRI, we evaluated the image findings of portal vein occlusion, the parenchymal signal change caused by hemodynamic alterations of the portal vein, and their combination showing the highest odds ratio (OR) to define the diagnostic criteria for radiological PVI detection (rPVI criteria). The diagnostic performance and recurrence-free survival were compared between the rPVI criteria and the presence of PVTT using McNemar's test and Kaplan-Meier method, respectively. Interobserver agreement was evaluated using Cohen's weighted ĸ statistics. Of 189 enrolled patients, 25 (13.2%) had PVI on histology. To diagnose PVI on MRI, either peripheral wedge-shaped arterial peritumoral hyperemia with an abrupt cut-off of a portal vein or the presence of PVTT had the highest OR (41.67, p<0.001). The sensitivity of PVI was significantly increased under this diagnostic criterion (64.0% to 88.0%; p=0.031) with comparable accuracy (95.2% vs. 94.7%; p>0.999). In terms of recurrence-free survival, the patient group with rPVI was significantly worse (p=0.017) compared with the patients without rPVI. Interobserver agreement of radiologic findings was substantial (ĸ=0.64). Diagnostic criteria for radiologically PVI detection increase the sensitivity more than the only presence of PVTT.

Raised Hematocrit at High Altitude: Its Relation to Sensorineural Hearing Loss

Abstract Background: Military troops deployed in high altitude areas (HAAs) may suffer from illnesses peculiar to the terrain which are usually due to hypoxia. The physiological dynamics at high altitude (HA) are different from those in the plains and hence environmental factors play an important role at HA. The effect, if any, of hemodynamic changes in terms of raised hemoglobin (Hb) levels in HA on otological disorders is not very well researched and needs to be explored further. This study was undertaken to study the clinical manifestations, if any, of the hemodynamic alterations in the inner ear and their correlation with the Hb levels after 1 year deployment at HA. Methods: A longitudinal descriptive study was conducted over 1 year duration at a Military Hospital located at HAA on 99 soldiers who were &lt;40 years of age with no history of prior ear complaints/ear surgery and with normal pure tone audiometry (PTA) thresholds and Hb levels at initial evaluation. Each soldier underwent PTA and Hb estimation twice: initially, at the time of induction, and later after completion of 1 year deployment at HAA. Statistical analysis was done using simple paired t-test. Results: On data analysis, no hearing loss was found in any participant of the study cohort at frequencies 500 Hz and 1 kHz in either ear on second evaluation. At 2 kHz, for left ear, the mean Hb level for the group with hearing thresholds greater than 25 dB was 17.07 g% with a standard deviation of 0.66, and for right ear, it was 16.95 g% with standard deviation of 0.64. At 4 kHz, the mean Hb level was 16.50 g% and 16.49 g% for hearing thresholds below and up to 25 dB for left and right ear, respectively. It was 16.99 g% and 16.96 g% for hearing thresholds above 25 dB. The results were statistically significant for both right and left ear at 4 kHz. Conclusion: A statistically significant deterioration of hearing thresholds for 4 kHz frequency with corresponding increase in Hb levels was observed in our study. Hb levels can therefore be used as a marker to ensure no further exposure to other risk factors like loud noise exposure, further deployment at higher altitudes to prevent deterioration, and progression of hearing loss.

Myocardial strain parameters in pulmonary hypertension are determined by changes in volumetric function rather than by hemodynamic alterations

PurposeTo investigate associations of cardiac magnetic resonance feature-tracking-derived left (LV) and right ventricular (RV) global myocardial peak strains and strain rates with volumetric function and hemodynamic parameters to identify the major determinants of myocardial strain alterations in pulmonary hypertension (PH). MethodsSixty-seven patients with PH or at risk of developing PH underwent right heart catheterization (RHC) and cine realtime imaging at 3 T. RHC parameters included mean pulmonary arterial pressure (mPAP), which was used for the diagnosis of PH. LV and RV volumetric function and feature-tracking-derived global radial, circumferential, and longitudinal (GLS) peak strains, together with their strain rates, were evaluated from cine images using routine software. Furthermore, myocardial strain parameters of 24 healthy subjects were evaluated as controls. Means were compared by t-test; relationships between parameters were investigated by correlation and regression analysis. ResultsCompared to controls, RV-GLS, all RV systolic strain rates and the LV systolic longitudinal strain rate showed lower magnitudes in PH (RV-GLS: −21 ± 4% vs. −16 ± 5%, p < 0.0001); the strongest univariate correlate to mPAP was the RV-GLS (r = 0.59). All LV and RV strain parameters yielded stronger correlations with their respective ejection fractions. In bi-linear models using mPAP and ejection fraction as predictors, mPAP remained significant only for diastolic LV radial and circumferential strain rates. ConclusionImpairment of myocardial strains is more strongly associated with alterations in LV and RV volumetric function parameters than elevated mPAP, therefore limiting diagnostic information of myocardial strain parameters in PH.

The Use of Doppler to Assess Hemodynamic Alterations in Maternal Common Femoral Veins in Uncomplicated Pregnancies: A Cohort Study

Objective: Pregnancy can induce the slowing of blood flow in the lower extremity veins and associated complications such as varicose veins. The objective of this study was to report the hemodynamic alterations in uncomplicated pregnancies during second and third trimesters using spectral Doppler. The specific aim was to compare the venous diameter and mean flow velocities of maternal common femoral veins (CFVs) during second and third trimesters of pregnancy. This was designed to assess the extent of pregnancy-induced hemodynamic changes as well as to establish a normative range of these values. Materials and Methods: This cohort study was conducted with 230 women during second and third trimesters of pregnancy. Grayscale sonography and spectral Doppler were used to record the diameter and mean flow velocity of maternal CFVs bilaterally. An independent sample t test was performed for the comparison of these between women with second and third trimesters of pregnancy. Statistical significance was set a P ≤ .05, a priori. Results: There was significant dilatation and a corresponding decrease in mean blood flow velocities in the CFVs in the participants in their third trimester compared with the second trimester of pregnancy. Conclusion: In this large cohort of participants, the CFV demonstrated statistically significant distension and slowing of blood flow with the advancement of their pregnancies.

Prognostic impact of thyroid dysfunction in patients with incident heart failure: a nationwide study

Abstract Background Thyroid hormones directly affect the cardiovascular system. Thyroid dysfunction can cause a variety of haemodynamic alterations and has been associated with an increased risk of atrial fibrillation (AF), heart failure (HF), and all-cause mortality. However, a paucity remains regarding knowledge on the prognostic impact of thyroid dysfunction in patients with HF. Purpose To examine the impact of the whole spectrum of thyroid dysfunction in patients with HF on the associated risk of AF, HF admissions, and all-cause mortality. Methods This Danish cohort study included patients with a first-time HF diagnosis from 2000–2021. According to blood samples within 6 months prior to the HF diagnosis, the study population was categorized based on thyroid function in 1) overt hypothyroidism, 2) subclinical hypothyroidism, 3) euthyroidism, 4) subclinical hyperthyroidism, and 5) overt hyperthyroidism. With up to one year of follow-up from the date of HF diagnosis, we used Aalen-Johansen estimator to examine the cumulative incidence frequency (CIF) of AF and HF admissions and Kaplan-Meier estimates to assess all-cause mortality. Multivariable Cox proportional hazard analysis was performed to investigate differences in outcomes among groups. Results Of the 7,380 individuals included in this study (56.6% female, median age 76.5 years [p25-p75: 67.9-84.1]), 102 (1.4%) had overt hypothyroidism, 1,706 (23.1%) had subclinical hypothyroidism, 4,374 (59.3%) were euthyroid, 691 (9.4%) had subclinical hyperthyroidism, and 507 (6.9%) had overt hyperthyroidism. Compared with euthyroid patients, the adjusted one-year hazard ratio (HR) for AF was 0.77 (95% CI, 0.49-1.20) for overt hypothyroidism, 1.01 (95% CI, 0.90-1.13) for subclinical hypothyroidism, 1.18 (95% CI, 1.01-1.38) for subclinical hyperthyroidism, and 1.19 (95% CI, 1.01-1.39) for overt hyperthyroidism (Figure). The adjusted one-year HR for HF hospitalizations was 1.51 (95% CI, 1.06-2.14) in patients with overt hypothyroidism, 1.07 (95% CI, 0.96-1.20) in patients with subclinical hypothyroidism, 0.99 (95% CI, 0.84-1.16) in patients with subclinical hyperthyroidism, and 1.26 (95% CI, 1.06-1.50) in patients with overt hyperthyroidism. The adjusted one-year HR for mortality was 1.81 (95% CI, 1.25-2.63) in patients with overt hypothyroidism, 1.25 (95% CI, 1.10-1.42) in patients with subclinical hypothyroidism, 1.15 (95% CI, 0.96-1.37) in patients with subclinical hyperthyroidism, and 1.46 (95% CI, 1.20-1.78) in patients with overt hyperthyroidism. Conclusion In patients with HF, overt and subclinical hyperthyroidism was associated with an increased rate of AF. Both hypo and hyperthyroid states were associated with increased risk of HF admission and mortality. Increased awareness regarding thyroid status in patients with HF is warranted.

Abstract 18258: Leucine Supplementation Improves Myocardial Function in a HFpEF Rat Model

Introduction: We previously documented that leucine supplementation protects from skeletal muscle atrophy by increasing skeletal muscle mass and force during hind limb immobilization. One of the proposed underlying mechanisms was the suppression of HDAC4 protein expression and increased nuclei accretion. Hypothesis: The present study aimed to examine whether the protective effects of leucine supplementation are also observed in the myocardium in an animal model of heart failure with preserved ejection fraction (HFpEF) and to assess the role of HDAC4 modulation. Methods: Female ZSF1 lean (control, con) and obese (HFpEF) rats were randomized at an age of 20 weeks to one of three groups: lean rats receiving standard chow (con), obese rats receiving standard chow (HFpEF), and obese rats receiving leucine-supplemented chow (3% w/w) for 12 weeks (HFpEF/leu). All animals underwent echocardiography at baseline and after 6 and 12 weeks. Prior to organ harvest left ventricular (LV) hemodynamics were measured invasively, blood samples were taken, cardiac mitochondrial function was assessed and LV tissue was collected for molecular and histological analyses. Results: Assessment of diastolic function revealed a 20% reduction of E/é in the HFpEF/leu group compared to untreated HFpEF. While no alterations of left ventricular hemodynamics were observed between the groups, stiffness factor β was significantly reduced in leucine-treated rats. Left ventricular mRNA levels of Collagen type I a1 and matrix metalloproteinase 2 were reduced by 25% and 22%, respectively. Assessment of mitochondrial oxidative phosphorylation revealed a significant improvement of complex-I- and complex-II mediated respiration in leucine-treated rats compared to HFpEF. Finally, HDAC4 protein expression levels were reduced by 40% in the HFpEF/leu group compared to HFpEF. Conclusions: This study presents beneficial effects of leucine supplementation on cardiac function, remodeling, and metabolic parameters in an HFpEF rat model. These benefits may be attributed to suppressed HDAC4 expression.

Abstract 16785: Hypertension Induces Metabolite Content Alterations in Hypoperfused Mouse Brain Cortex

Introduction and aims: Hypertension is one of the main risk factors for dementias. To understand the link between vasculature and neuronal dysfunction in hypertension-induced cognitive impairment we leverage MRI, a translational imaging tool that let us concomitantly analyze cerebral structure, function and metabolism. Methods: Transverse aortic constriction (TAC) was performed in C57Bl/6J mice to induce cerebral hypertension. The brain was characterized by structural MRI, cerebral blood flow (CBF) was analyzed by perfusion MRI and cortical cerebral metabolism was characterized by point-resolved spectroscopy performed on a small-animal dedicated 7T MRI. Finally, we characterized the microvascular structure in regions impacted by hypertension by immunofluorescence. Results: TAC mice shown hemodynamic alterations in cortical CBF compared to sham mice (A). Macroscopic volumetric analyses of the cortex shown no significant alterations, however hypoperfused cortical regions shown local cortical thickening, suggesting a local swelling due to inflammatory processes (B). The histological microvascular analysis evidenced capillary Blood-Brain Barrier loss of integrity (C). Finally, this cortical region shown alterations in glucose and glutamine metabolite concentration measured by MR spectroscopy (D). Conclusions: Leveraging MRI we have concomitantly characterized the cortical structure, function and metabolism in TAC-hypertensive mice. These alterations in cerebral blood flow and metabolism of glucose/glutamine are biomarkers of ongoing cerebral injury and are potential targets of further investigation to shed light on the interplay between vascular and neuronal injury in hypertension.

Abstract 18906: Post-COVID Hemodynamic Pathophysiology: Prevalence of Dysfunctional Breathing and Preload Insufficiency Using Novel Invasive Cardiopulmonary Exercise Testing

Introduction: The pathophysiologic mechanisms underlying persistent post-COVID cardiorespiratory symptoms remain understudied, despite the significant worldwide prevalence. Invasive cardiopulmonary exercise testing (iCPET) is a novel investigation that can inform our understanding of underlying hemodynamic abnormalities. Research Question: What is the prevalence of dysfunctional breathing (DB) and preload insufficiency (PI) in post-COVID patients who undergo iCPET? Methods: We studied hemodynamic characteristics in a cohort of 52 post-COVID patients who underwent iCPET in a sitting bicycle. The protocol augments CPET with continuous hemodynamic and laboratory data from pulmonary artery catheterization and arterial line. PI is defined as abnormally low right atrial pressure during exercise and reduced peak cardiac output percentage of predicted. DB is characterized by exercise-induced oscillatory ventilation. Results: The study cohort had a mean age of 40.8 years, and 36 of the 52 patients (69.2%) were female. iCPET revealed the prevalence of only DB as 15.4%, only PI as 34.6%, both DB and PI as 34.6%, and neither DB nor PI as 15.4%. These 4 sub-groups were subsequently compared for analysis. Notably, the cardiac output percentage of predicted at peak exercise was significantly different between the 4 groups (95.4%, 81.2%, 85.1%, 102.9%; p=0.007). The differential between baseline (sitting) and peak (maximal exercise) right atrial pressure was also significantly different between the 4 groups (0.00, 0.056, 0.333, 4.875; p=0.026). Our study suggests that PI and DB are common entities noted in symptomatic post-COVID patients, and may co-occur. Conclusion: This study is a first step towards understanding the altered hemodynamics that drive common symptoms in post-COVID patients. iCPET yields physiologic mechanistic information that could inform targeted interventions.

The EVA (Early Vascular Aging) Study: Association of Central Obesity With Worse Arterial Health After Preeclampsia.

Background Women with preeclampsia have a higher risk of cardiovascular disease. This is partly explained by the worse arterial health after preeclampsia. Central obesity (CO) is a risk factor for both preeclampsia and cardiovascular disease. Whether CO contributes to further worsening of arterial health after preeclampsia remains unclear. Our objective was to evaluate the effect of CO and previous preeclampsia on arterial hemodynamics. Methods and Results We studied 40 women with previous preeclampsia (<6 years) and 40 age-matched controls with previous normotensive pregnancy in the same timeframe. We estimated arterial hemodynamics with validated techniques combining applanation tonometry and echocardiography. CO was defined as a waist-to-hip ratio ≥0.85. Differences in arterial hemodynamics across the 3 groups (preeclampsia with CO, preeclampsia without CO, and controls) were assessed with multivariable linear regression models adjusted for potential confounders. Twenty-six (65%) of the participants with preeclampsia had CO compared with 18 (45%) controls. Mean waist-to-hip ratio in patients with preeclampsia with CO, those with preeclampsia and no CO, and controls was 0.94±0.05, 0.80±0.04, and 0.83±0.07, respectively. In multivariable analyses, women with preeclampsia and CO had higher central blood pressure, arterial stiffness (carotid-femoral pulse wave velocity), steady arterial load (systemic vascular resistance), and wave reflections (reflected pressure wave amplitude, augmentation index) compared with controls (P<0.05 for each). Fewer hemodynamic domains were altered in the preeclampsia with no CO group, with higher central diastolic blood pressure, systemic vascular resistance, and wave reflections than controls (P<0.05). Conclusions Women with previous preeclampsia who also experience CO have the greatest alterations in arterial health and hemodynamics. Patients with preeclampsia with CO may represent a higher-risk subgroup who could be targeted for risk stratification and primary prevention of cardiovascular disease.

A Microsurgical Arteriovenous Malformation Model on Saphenous Vessels in the Rat.

Arteriovenous malformation (AVM) is an anomaly of blood vessel formation. Numerous models have been established to understand the nature of AVM. These models have limitations in terms of the diameter of the vessels used and the impact on the circulatory system. Our goal was to establish an AVM model that does not cause prompt and significant hemodynamic and cardiac alterations but is feasible for follow-up of the AVM's progression. Sixteen female rats were randomly divided into sham-operated and AVM groups. In the AVM group, the saphenous vein and artery were interconnected using microsurgical techniques. The animals were followed up for 12 weeks. Anastomosis patency and the structural and hemodynamic changes of the heart were monitored. The hearts and vessels were histologically analyzed. During the follow-up period, shunts remained unobstructed. Systolic, diastolic, mean arterial pressure, and heart rate values slightly and non-significantly decreased in the AVM group. Echocardiogram results indicated minor systolic function impact, with slight and insignificant changes in aortic pressure and blood velocity, and minimal left ventricular wall enlargement. The small-caliber saphenous AVM model does not cause acute hemodynamic changes. Moderate but progressive alterations and venous dilatation confirmed AVM-like features. The model seems to be suitable for studying further the progression, enlargement, or destabilization of AVM.

Comparison of Intranasal Versus Intravenous Dexmedetomidine to Attenuate Haemodynamic Response of Laryngoscopy and Endotracheal Intubation in Elective Lumbar Spine Surgery: A Randomized Controlled Study

Background: In general anaesthesia, hemodynamic alterations during endotracheal intubation are vital concerns. The efficacy of intranasal and intravenous Dexmedetomidine (DEX) in decreasing the stress response generated by laryngoscopy and endotracheal intubation was investigated in this study. Methods: Seventy adults were randomised into two groups in this prospective, randomised, double-blind study: Group DIV (n=35) and Group DIN (n=35). Dexmedetomidine (DEX) infusion (0.5 μg /kg) was administered intravenously over 40 minutes to the DIV group and intranasally (1 μg /kg) to the DIN group 40 minutes before induction. The primary outcome was to compare the mean arterial pressure (MAP) between the two groups starting 40 minutes before induction and continuing every 10 minutes until induction of anaesthesia, at the time of intubation, and then every minute afterwards until 5 minutes, 7 minutes, and 10 minutes following intubation. Comparisons of heart rate (HR), systolic (SBP) and diastolic blood pressure (DBP), sedation and any adverse effects were the secondary outcomes. Results: The two groups had no statistically significant difference in MAP, HR, SBP and DBP. The DIV group's preoperative sedation score before induction was significantly higher than the DIN group's (P = 0.014). Conclusion: This study demonstrates that dexmedetomidine administered intravenously is equally efficient as intranasal dexmedetomidine in attenuating hemodynamic response during laryngoscopy and intubation.

Retinal hypoperfusion detected by wide-field optical coherence tomographic angiography in a case of retinal racemose hemangioma.

Retinal racemose hemangioma (RRH) is a rare, non-hereditary arteriovenous malformation characterized by the appearance of dilated and tortuous retinal vessels. RRH can develop complications associated with retinal ischemia, such as vitreous hemorrhage, retinal vein occlusion and neovascular glaucoma. Here, we report a case of RRH with retinal hypoperfusion detected by wide-field swept source optical coherence tomography angiography (OCTA), which was not unambiguously illustrated by fluorescein angiography (FA). Case report. A 57-year-old woman was referred to our hospital for the evaluation of severe retinal vascular tortuosity, dilation and retinal hemorrhages in the left eye. Fundus examination revealed arteriovenous communications temporal to the fovea and multiple microaneurysms surrounded by retinal hemorrhages at the midperipheral temporal fundus. In FA, multiple hyperfluorescent lesions with leakage corresponding to microaneurysms were observed in the temporal and lower midperipheral areas; however, non-perfused areas were apparently absent. By contrast, wide-field OCTA clearly showed low-density retinal capillaries in the superotemporal quadrant in comparison with those in the inferotemporal quadrant. Wide-field OCTA detected sparse retinal capillaries, which were not well illustrated by FA, in a patient with RRH. This indicates the presence of low-grade retinal hypoperfusion caused by altered retinal hemodynamics, potentially leading to ischemia-related retinal disorders during a prolonged course, in patients with clinically quiescent RRH.