Hemodynamic Monitoring of Pediatric Patients With Heart Failure and Pulmonary Hypertension Using CardioMEMS.

Background: The CardioMEMS is an implantable device for hemodynamic monitoring approved by the US Food and Drug Administration for adult patients with heart failure. It has been used in the adult population without structural heart disease and with congenital heart diseases, but we do not have data in the pediatric population. Methods: We report the initial single-center experience of the CardioMEMS implantation in children. Feasibility of device implantation, procedural outcomes, and clinical utility in the pediatric population were evaluated. Results: The CardioMEMS device was implanted without technical complications in 8 pediatric patients (mean age 7 years and mean weight 27.9 kg) with pulmonary hypertension (6/8, 75%) and heart failure (2/8, 25%). The device was delivered via femoral access in 7 (85%) patients and implanted in the left pulmonary artery in 7 (85%). The noninvasive recording of pulmonary pressures in patients with pulmonary hypertension allowed the monitoring of the evolution of mean pulmonary artery pressure, intensifying vasodilator treatment, and avoiding control cardiac catheterizations. In patients with heart failure, pulmonary hemodynamic monitoring guided the decongestive treatment prior to heart transplantation. Conclusions: The implantation of CardioMEMS in the pediatric population is a feasible procedure that allows the noninvasive hemodynamic monitoring of patients with heart failure and pulmonary hypertension. Its implementation in selected patients aids in outpatient follow-up and therapeutic management of patients with complex cardiac conditions, avoiding invasive procedures that require hospitalization. Further large-scale studies in the pediatric population are recommended.

A Novel Hemodynamic Index Characterizing Mitral Regurgitation Undergoing Transcatheter Edge-to-Edge Repair: The MPF.

Background: Hemodynamic impact of residual mitral regurgitation (MR) after transcatheter edge-to-edge repair (TEER) is not always univocally measured by transesophageal echocardiographic (TEE) assessment alone. When analyzing TEER procedure result, operators often encounter discrepancy between TEE guidance and invasive hemodynamic monitoring. Objectives: This study sought to investigate the role of invasive hemodynamic monitoring during mitral valve TEER procedure on top of TEE guidance. Methods: We analyzed 78 patients with moderate-to-severe or severe MR who underwent TEER. Mitral pulse pressure fraction (MPF) was extracted from intraprocedural continuous left atrial pressure monitoring. Twenty-three patients with the same grade of MR not undergoing TEER were included as a control group. At follow-up, clinical and functional status in the majority of patients undergoing TEER were reassessed by NYHA classification and the 12-item Kansas City Cardiomyopathy Questionnaire (KCCQ). Results: TEER significantly reduced MR burden on both TEE guidance and invasive hemodynamic monitoring. Post-TEER MPF was significantly reduced compared to both pre-TEER setting (P < 0.001) and control group (P < 0.001). At follow-up, while MR reduction assessed by TEE was associated with an improved functional status in terms of the 12-item KCCQ but not of NYHA classification, a greater reduction in MPF was associated with a significant amelioration of both NYHA classification (P = 0.036) and 12-item KCCQ (P = 0.032). Conclusions: MPF could provide an immediate estimate of the real hemodynamic impact of MR and a prompt prediction of the functional improvement after TEER.

Randomized single-blinded study comparing sedation effectiveness and hemodynamic stability of remifentanil vs dexmedetomidine infusion for electrophysiology procedures in patients of National Heart Institute cathlab.

BACKGROUND: While studies comparing the effectiveness of remifentanil and dexmedetomidine are prevalent in other nations, using remifentanil alone is uncommon in Malaysia. This research aims to evaluate the effectiveness of sedation with remifentanil or dexmedetomidine infusion in monitored anesthesia care for electrophysiology procedures. METHODS: This study is a single-center, single-blinded, prospective randomized clinical study. One hundred twenty patients were randomized into two groups (remifentanil vs dexmedetomidine). Demographic characteristics and clinical outcomes, including level of sedation, vital signs, and patient satisfaction were monitored and recorded. RESULTS: Group R showed a higher mean observer's assessment of alertness/sedation score (3.9 ± 0.7 vs 3.6 ± 0.8; p = 0.008), mean arterial pressure (92.0 ± 12.0 vs 83.0 ± 13.0 mmHg; p < 0.001), heart rate (82.0 ± 20.0 vs 73.0 ± 18.0 beats/min; p = 0.006), systolic blood pressure (139.0 ± 16.0 vs 123.0 ± 17.0 mmHg; p < 0.001) and diastolic blood pressure (75.0 ± 13.0 vs 69.0 ± 14.0 mmHg; p = 0.009) than Group D. Oxygen saturation (99.0 ± 1.0%; p = 0.220) and respiration rate (16.0 ± 3.0 breaths/min; p = 0.361) for both groups were the same. Adverse events, including hypotension, bradycardia, and respiratory depression were observed in both groups. Both groups gave positive responses ranging from fair to good for patient satisfaction. CONCLUSION: Dexmedetomidine is a better choice of anesthesia as it was associated with a higher level of sedation, more stable hemodynamics, lower incidence of adverse events, and better patient satisfaction.

Efficacy and features of balloon-occluded transarterial chemoembolization for hepatocellular carcinoma: a narrative review.

Background and Objective: Systemic therapy for hepatocellular carcinoma (HCC) is recommended in transarterial chemoembolization (TACE)-refractory and unsuitable cases. In Japan, TACE is broadly classified into conventional TACE (C-TACE), balloon occluded TACE (B-TACE), and drug-eluting beads TACE. However, the type of TACE recommended for TACE-refractory or unsuitable cases has not been elucidated, and a targeted approach for individual cases and appropriate TACE selection is important. B-TACE is considered a valuable therapeutic option in the management of HCC. The technique involves the precise placement of a microcatheter with a balloon into the target hepatic artery, followed by selective occlusion of the hepatic artery, including tumor-feeding vessels, using the balloon. By leveraging the hemodynamic changes resulting from arterial occlusion, B-TACE enables effective accumulation of chemotherapeutic agents within the tumor. Incorporating B-TACE into the treatment strategy for HCC is of utmost importance. Therefore, this article provides an overview of the technique. Methods: A comprehensive review of all available literature in the English language through December 1, 2023 utilizing PubMed was conducted. Key Content and Findings: In the intermediate stage, TACE and systemic therapy play complementary roles, and it is important to select a treatment strategy that considers tumor status and hepatic reserve. However, no study has investigated the various types of TACE in the treatment of such patients. Currently, TACE in Japan is broadly classified into C-TACE, B-TACE, and drug-eluting beads TACE (DEB-TACE). This article outlines the evolution of B-TACE for HCC. We identified retrospective and prospective studies evaluating B-TACE. In this review, we evaluate data on B-TACE for HCC. Conclusions: In the era of systemic therapy, B-TACE may play a complementary and synergy effect role.

Effectiveness of Earplugs and Eye Masks on Sleep Quality and Fatigue Among Nonventilated Patients in an Intensive Care Unit.

BACKGROUND: Sleep is a basic physiological need and is imperative for healing and rejuvenation. However, the environment of the intensive care unit (ICU), including loud sounds and bright lights, can undermine patients' sleep quality. AIM: This study was designed to determine the effectiveness of overnight use of earplugs and eye masks to improve sleep quality and potentially influence hemodynamic parameters and mitigate fatigue among nonventilated patients in an ICU. MATERIALS AND METHODS: This experimental study was conducted among 84 nonventilated patients in an ICU. The patients were evenly divided between an intervention group (n=42) and a control group (n=42). The intervention group patients received earplugs and eye masks for three consecutive nights from 10:30 pm to 6:30 am, while the control group patients received routine care. Clinical data, responses to the Richards-Campbell sleep questionnaire, and rankings on a numerical fatigue scale were collected before (pretest) and after the intervention each night and the next morning (posttests 1, 2, and 3). RESULTS: The results revealed a significant reduction in fatigue. At pretest, fatigue scores in the study group were 4.19±1.64. The score was significantly reduced to 3.40±1.39 at posttest 1 and then to 2.21±1.00 at posttest 3 (p<0.0001). The sleep quality for the study group showed a significant improvement from the pretest score of 43.73±8.27 to 60.35±6.85 at posttest 3 (p<0.001), whereas the control group had slightly worse sleep quality, with 40.64±8.67 at pretest and 45.63±6.95 at posttest 3. CONCLUSIONS: Continuous patient monitoring is an essential nursing care activity in ICUs while ensuring good-quality sleep promotes healing and reduces fatigue. Sleep quality can be supported by devices such as earplugs and eye masks to limit undue disturbances in the ICU settings.

The evolution and future directions of bypass surgery.

Cerebral bypass surgery is one of the most complex and elegant procedures in neurosurgery. It involves several meticulous steps that test the skills of even the most prepared neurosurgeons. This surgery has transcended its traditional role in arterial stenosis and atherosclerosis, expanding its applications to include flow preservation techniques for complex conditions such as aneurysms, tumors, and vascular malformations. The decreased number of procedures performed across many hospitals reflects the development of newer endovascular therapies but is also due to the results of the extracranial-intracranial bypass study, the Carotid Occlusion Surgery Study, and the Carotid and Middle Cerebral Artery Occlusion Surgery Study, which have raised questions about the efficacy of cerebral bypass surgery for individuals with carotid artery occlusion who are prone to ischemic stroke. Despite this, there is still a potential benefit of bypass surgery for patients with hemodynamic impairment refractory to medical management. Also, revascularization in moyamoya vasculopathy is an effective strategy for preventing ischemic and hemorrhagic events in both children and adults. Additionally, innovations in the technique, such as the flow-regulated bypass and intraoperative flow assessment, aim to minimize perioperative morbidity. Despite bypass surgery being less performed in this current era, the teaching and development of these skills are still encouraged for future neurosurgeons, as a role for bypass will exist for the foreseeable future.

In-silico analysis of hemodynamic indicators in idealized stented coronary arteries for varying stent indentation.

In this work, we investigate the effects of stent indentation on hemodynamic indicators in stented coronary arteries. Our aim is to assess in-silico risk factors for in-stent restenosis (ISR) and thrombosis after stent implantation. The proposed model is applied to an idealized artery with Xience V stent for four indentation percentages and three mesh refinements. We analyze the patterns of hemodynamic indicators arising from different stent indentations and propose an analysis of time-averaged WSS (TAWSS), topological shear variation index (TSVI), oscillatory shear index (OSI), and relative residence time (RRT). We observe that higher indentations display higher frequency of critically low TAWSS, high TSVI, and non-physiological OSI and RRT. Furthermore, an appropriate mesh refinement is needed for accurate representation of hemodynamics in the stent vicinity. The results suggest that disturbed hemodynamics could play a role in the correlation between high indentation and ISR.

Comparison of 4% Albumin and Ringer's Acetate on Hemodynamics in On-pump Cardiac Surgery: An Exploratory Analysis of a Randomized Clinical Trial.

OBJECTIVES: Compare hemodynamics between 4% albumin and Ringer's acetate. DESIGN: Exploratory analysis of the double-blind randomized ALBumin In Cardiac Surgery trial. SETTING: Single-center study in Helsinki University Hospital. PARTICIPANTS: We included 1,386 on-pump cardiac surgical patients. INTERVENTION: We used 4% albumin or Ringer's acetate administration for cardiopulmonary bypass priming, volume replacement intraoperatively and 24 hours postoperatively. MEASUREMENTS AND MAIN RESULTS: Hypotension (time-weighted average mean arterial pressure of <65 mmHg) and hyperlactatemia (time-weighted average blood lactate of >2 mmol/L) incidences were compared between trial groups in the operating room (OR), and early (0-6 hours) and late (6-24 hours) postoperatively. Associations of hypotension and hyperlactatemia with the ALBumin In Cardiac Surgery primary outcome (≥1 major adverse event [MAE]) were studied. In these time intervals, hypotension occurred in 118, 48, and 17 patients, and hyperlactatemia in 313, 131, and 83 patients. Hypotension and hyperlactatemia associated with MAE occurrence. Hypotension did not differ between the groups (albumin vs Ringer's: OR, 8.8% vs 8.5%; early postoperatively, 2.7% vs 4.2%; late postoperatively, 1.2% vs 1.3%; all p > 0.05). In the albumin group, hyperlactatemia was less frequent late postoperatively (2.9% vs 9.1%; p < 0.001), but not earlier (OR, 22.4% vs 23.6%; early postoperatively, 7.9% vs 11.0%; both p > 0.025 after Bonferroni-Holm correction). CONCLUSIONS: In on-pump cardiac surgery, hypotension and hyperlactatemia are associated with the occurrence of ≥1 MAE. Compared with Ringer's acetate, albumin did not decrease hypotension and decreased hyperlactatemia only late postoperatively. Albumin's modest hemodynamic effect is concordant with the finding of no difference in MAEs between albumin and Ringer's acetate in the ALBumin In Cardiac Surgery trial.

Evaluating tissue hypoxia and the response to fluid administration in septic shock patients: a metabolic cluster analysis.

BACKGROUND: The selection of adequate indicators of tissue hypoxia for guiding the resuscitation process of septic patients is a highly relevant issue. Current guidelines advocate for the use of lactate as sole metabolic marker, which may be markedly limited, and the integration of different variables seems more adequate. In this study, we explored the metabolic profile and its implications in the response to the administration of a fluid challenge in early septic shock patients. METHODS: Observational study including septic shock patients within 24 h of ICU admission, monitored with a cardiac output estimation system, with ongoing resuscitation. Hemodynamic and metabolic variables were measured before and after a fluid challenge (FC). A two-step cluster analysis was used to define the baseline metabolic profile, including lactate, central venous oxygen saturation (ScvO2), central venous-to-arterial carbon dioxide difference (PcvaCO2), and PcvaCO2 corrected by the difference in arterial-to-venous oxygen content (PcvaCO2/CavO2). RESULTS: Seventy-seven fluid challenges were analyzed. Cluster analysis revealed two distinct metabolic profiles at baseline. Cluster A exhibited lower ScvO2, higher PcvaCO2, and lower PcvaCO2/CavO2. Increases in cardiac output (CO) were associated with increases in VO2 exclusively in cluster A. Baseline isolated metabolic variables did not correlate with VO2 response, and changes in ScvO2 and PcvaCO2 were associated to VO2 increase only in cluster A. CONCLUSIONS: In a population of early septic shock patients, two distinct metabolic profiles were identified, suggesting tissue hypoxia or dysoxia. Integrating metabolic variables enhances the ability to detect those patients whose VO2 might increase as results of fluid administration.

Association between cytokines, nitric oxide, hemodynamic and microcirculation in a porcine model of sepsis.

Systemic inflammation and hemodynamic or microvascular alterations are a hallmark of sepsis and play a role in organs hypoperfusion and dysfunction. Pimobendan, an inodilator agent, could be an interesting option for inotropic support and microcirculation preservation during shock. The objectives of this study were to evaluate effect of pimobendan on cytokine and nitric oxide (NO) release and investigate whether changes of macro and microcirculation parameters are associated with the release of cytokines and NO in pigs sepsis model. After circulatory failure, induced by intravenous inoculation of live Pseudomonas aeruginosa, eight animals were treated with pimobendan and eight with placebo. Pimobendan did not affect cytokines secretion (TNF-α, IL-6 and IL-10), but decreased time-dependently NO release. Data of macro and microcirculation parameters, NO and TNF- α recorded at the time of circulatory failure (Thypotension) and the time maximum of production cytokines was used for analyses. A positive correlation was observed between TNF-α and cardiac index (r = 0.55, p = 0.03) and a negative with systemic vascular resistance (r = -0.52, p = 0.04). Positive correlations were seen both between IL-10, 30 min after resuscitation (T30min), and systolic arterial pressure (r = 0.57, p = 0.03) and cardiac index (r = 0.67, p = 0.01), and also between IL-6, taken 2 h after resuscitation and systolic arterial pressure (r = 0.53, p = 0.04). Negative correlations were found between IL-10 and lactate, measured resuscitation time (r = -0.58, p = 0.03). Regarding microcirculation parameters, we observed a positive correlation between IL-6 and IL-10 with the microvascular flow index (r = 0.52, p = 0.05; r = 0.84, p = 0.0003) and a negative correlation with the heterogeneity index with TNF-α and IL-10 (r = -0.51, p = 0.05; r = -0.74, p = 0.003) respectively. NO derivatives showed a positive correlation with temperature gradient (r = 0.54, p = 0.04). Pimobendan did not show anti-inflammatory effects in cytokines release. Our results also, suggest changes of macro- and microcirculation are associated mainly with low levels of IL-10 in sepsis.

Comparing the efficacy of adrenaline, clonidine, and dexmedetomidine in enhancing local anesthesia for impacted third molar extraction: a randomized controlled trial.

Background: In human dentition, the most commonly impacted teeth are the mandibular third molars (M3M). The removal or extraction of these teeth often causes anxiety in patients due to the perceived pain involved in the process. Therefore, pain must be effectively managed using anesthesia. The use of newer local anesthetic drugs can help minimize side effects and drug interactions. Traditionally, adrenaline is used as a vasoconstrictor along with lignocaine. When combined with lignocaine, the alpha agonists dexmedetomidine and clonidine can extend the duration of anesthesia, thereby reducing the need for additional pain-relieving medications. Methods: This study used a randomized, triple-blind, parallel-arm design. Sixty patients were screened, and 45 systemically healthy patients requiring unilateral surgical removal of impacted mandibular third molars with similar difficulty (moderate-to-difficult according to the Modified Pederson's Index) were included in the study. Patients were allocated into three groups as follows: Group A: 2% Lignocaine Hydrochloride with 1:100,000 Adrenaline, Group C: 2% Lignocaine Hydrochloride with 15 µg/mL Clonidine, and Group D: 2% Lignocaine Hydrochloride with 1 µg/mL Dexmedetomidine. The evaluated parameters were the time of onset of anesthesia, depth of anesthesia, hemodynamic parameters, and duration of postoperative analgesia. Results: Group D had a faster onset of action and prolonged duration of postoperative analgesia compared with Groups A and C. No statistically significant differences were observed between the three groups in terms of the depth of anesthesia and hemodynamic parameters. Conclusion: Group D exhibited a significantly more rapid onset of anesthesia than Groups A and C, and the postoperative analgesic effect in Group D was significantly prolonged (7.22 hours) compared with that in Groups A (4.54 hours) and C (2.1 hours). Patients receiving the Group D solution experienced an extended period of comfort without the need for analgesics for up to 7.22 hours post-procedure.

Observation of intracranial artery and venous sinus hemodynamics using compressed sensing-accelerated 4D flow MRI: performance at different acceleration factors.

Objective: To investigate the feasibility and performance of 4D flow MRI accelerated by compressed sensing (CS) for the hemodynamic quantification of intracranial artery and venous sinus. Materials and methods: Forty healthy volunteers were prospectively recruited, and 20 volunteers underwent 4D flow MRI of cerebral artery, and the remaining volunteers underwent 4D flow MRI of venous sinus. A series of 4D flow MRI was acquired with different acceleration factors (AFs), including sensitivity encoding (SENSE, AF = 4) and CS (AF = CS4, CS6, CS8, and CS10) at a 3.0 T MRI scanner. The hemodynamic parameters, including flow rate, mean velocity, peak velocity, max axial wall shear stress (WSS), average axial WSS, max circumferential WSS, average circumferential WSS, and 3D WSS, were calculated at the internal carotid artery (ICA), transverse sinus (TS), straight sinus (SS), and superior sagittal sinus (SSS). Results: Compared to the SENSE4 scan, for the left ICA C2, mean velocity measured by CS8 and CS10 groups, and 3D WSS measured by CS6, CS8, and CS10 groups were underestimated; for the right ICA C2, mean velocity measured by CS10 group, and 3D WSS measured by CS8 and CS10 groups were underestimated; for the right ICA C4, mean velocity measured by CS10 group, and 3D WSS measured by CS8 and CS10 groups were underestimated; and for the right ICA C7, mean velocity and 3D WSS measured by CS8 and CS10 groups, and average axial WSS measured by CS8 group were also underestimated (all p < 0.05). For the left TS, max axial WSS and 3D WSS measured by CS10 group were significantly underestimated (p = 0.032 and 0.003). Similarly, for SS, mean velocity, peak velocity, average axial WSS measured by the CS8 and CS10 groups, max axial WSS measured by CS6, CS8, and CS10 groups, and 3D WSS measured by CS10 group were significantly underestimated compared to the SENSE4 scan (p = 0.000-0.021). The hemodynamic parameters measured by CS4 group had only minimal bias and great limits of agreement compared to conventional 4D flow (SENSE4) in the ICA and every venous sinus (the max/min upper limit to low limit of the 95% limits of agreement = 11.4/0.03 to 0.004/-5.7, 14.4/0.05 to -0.03/-9.0, 12.6/0.04 to -0.03/-9.4, 16.8/0.04 to 0.6/-14.1; the max/min bias = 5.0/-1.2, 3.5/-1.4, 4.5/-1.1, 6.6/-4.0 for CS4, CS6, CS8, and CS10, respectively). Conclusion: CS4 strikes a good balance in 4D flow between flow quantifications and scan time, which could be recommended for routine clinical use.

Hemodynamic monitoring and echocardiographic evaluation in cardiogenic shock.

Cardiogenic shock (CS) is characterized by the presence of a state of tissue hypoperfusion secondary to ventricular dysfunction. Hemodynamic monitoring allows us to obtain information about cardiovascular pathophysiology that will help us make the diagnosis and guide therapy in CS situations. The most used monitoring system in CS is the pulmonary artery catheter since it provides key hemodynamic variables in CS, such as cardiac output, pulmonary artery pressure, and pulmonary artery occlusion pressure. On the other hand, echocardiography makes it possible to obtain, at the bedside, anatomical and hemodynamic data that complement the information obtained through continuous monitoring devices. CS monitoring can be considered multimodal and integrative by including hemodynamic, metabolic, and echocardiographic parameters that allow describing the characteristics of CS and guiding therapeutic interventions during hemodynamic resuscitation.

Stroke Volume and Stroke Volume Variation, but not Cardiac Index Is Associated With Survival of Majorly Burned Patients in Early Burn Shock.

Adequate fluid therapy is crucial to maintain organ function after burn trauma. Major burns lead to a systemic response with fluid loss and cardiac dysfunction. To guide fluid therapy, measurement of cardiac pre- and afterload is helpful. Whereas cardiac function is usually measured after admission to intensive care unit (ICU), in this study, hemodynamic monitoring was performed directly after arrival at hospital. We conducted a prospective cohort study with inclusion of 19 patients (male/female 13/6, 55 ± 18 years, mean total body surface area 36 ± 19%). Arterial waveform analysis (PulsioFlexProAqt®, Getinge) was implemented immediately after admission to hospital to measure cardiac pre- and afterload and to guide resuscitation therapy. Cardiac parameters 3.75 (2.67-6.0) h after trauma were normal regarding cardiac index (3.45 ± 0.82) L/min/m², systemic vascular resistance index (1749 ± 533) dyn sec/cm5 m2, and stroke volume (SV; 80 ± 20) mL. Stroke volume variation (SVV) was increased (21 ± 7) % and associated with mortality (mean SVV survivors vs nonsurvivors 18.92 (±6.37) % vs 27.6 (±5.68) %, P = .017). Stroke volume was associated with mortality at the time of ICU-admission (mean SV survivors vs nonsurvivors 90 (±20) mL vs 50 (±0) mL, P = .004). Changes after volume challenge were significant for SVV (24 ± 9 vs19 ± 8%, P = .01) and SV (68 ± 24 vs 76 ± 26 mL, P = .03). We described association of SVV and SV with survival of severely burned patients in an observational study. This indicates high valence of those parameters in the early postburn period. The use of an autocalibrated device enables a very early monitoring of parameters relevant to burn shock survival.

Influence of an improvement in frontal lobe hemodynamics on neurocognitive function in adult patients with moyamoya disease.

BACKGROUND: In adults, moyamoya disease (MMD) often presents with slight neurocognitive impairment, which may result from frontal lobe hemodynamic insufficiency. METHODS: In this study, we performed revascularization surgery by superficial temporal artery-anterior cerebral artery (ACA) direct bypass in 20 adults with MMD with poor anterograde ACA flow (Group M). The pre- and postoperative neurocognitive test results of these patients were retrospectively analyzed. The comparative group (Group C) included 23 patients with unruptured aneurysms or brain tumors who underwent craniotomy, as well as the same neurocognitive tests as Group M. We calculated the compositive frontal lobe function index (CFFI) based on the results of seven neurocognitive tests for each patient, and the difference between the pre- and postoperative CFFI values (CFFI Post - Pre) was compared between the two groups. RESULTS: Frontal perfusion improved postoperatively in all patients in Group M. The CFFI Post - Pre was significantly higher in Group M than in Group C (0.23 ± 0.44 vs. - 0.20 ± 0.32; p < 0.001). After adjusting for postoperative age, sex, preoperative non-verbal intelligence quotient, and preoperative period of stress, Group M had a significantly higher CFFI Post - Pre than Group C in the multiple regression analysis (t value = 4.01; p < 0.001). CONCLUSION: Improving frontal lobe hemodynamics might be the key for improving neurocognitive dysfunction in adults with MMD. The surgical indication and method should be considered from the perspective of both stroke prevention and neurocognitive improvement or protection.

Capturing physiological hemodynamic flow and mechanosensitive cell signaling in vessel-on-a-chip platforms.

Recent advances in organ chip (or, "organ-on-a-chip") technologies and microphysiological systems (MPS) have enabled in vitro investigation of endothelial cell function in biomimetic three-dimensional environments under controlled fluid flow conditions. Many current organ chip models include a vascular compartment; however, the design and implementation of these vessel-on-a-chip components varies, with consequently varied impact on their ability to capture and reproduce hemodynamic flow and associated mechanosensitive signaling that regulates key characteristics of healthy, intact vasculature. In this review, we introduce organ chip and vessel-on-a-chip technology in the context of existing in vitro and in vivo vascular models. We then briefly discuss the importance of mechanosensitive signaling for vascular development and function, with focus on the major mechanosensitive signaling pathways involved. Next, we summarize recent advances in MPS and organ chips with an integrated vascular component, with an emphasis on comparing both the biomimicry and adaptability of the diverse approaches used for supporting and integrating intravascular flow. We review current data showing how intravascular flow and fluid shear stress impacts vessel development and function in MPS platforms and relate this to existing work in cell culture and animal models. Lastly, we highlight new insights obtained from MPS and organ chip models of mechanosensitive signaling in endothelial cells, and how this contributes to a deeper understanding of vessel growth and function in vivo. We expect this review will be of broad interest to vascular biologists, physiologists, and cardiovascular physicians as an introduction to organ chip platforms that can serve as viable model systems for investigating mechanosensitive signaling and other aspects of vascular physiology.

Correlation and concordance of carotid Doppler ultrasound and echocardiography with invasive cardiac output measurement in critically ill patients.

BACKGROUND: Critical care management heavily relies on accurate cardiac output (CO) measurement. Echocardiography has been a mainstay in non-invasive cardiac monitoring; however, its comparability to invasive methods warrants further exploration. Recent studies have suggested the potential of carotid Doppler measurements as a promising approach to estimate CO. Despite this potential, the literature presents mixed outcomes regarding its reliability and accuracy. This study aims to evaluate the correlation and concordance between carotid Doppler ultrasonography and invasive hemodynamic monitoring in estimating CO in critically ill patients. Furthermore, it assesses the concordance and correlation between echocardiography CO and the standard invasive CO measurements. METHODS: This concordance study involved critically ill adults requiring invasive CO measurement. Patients with arrhythmias, severe valvulopathy, pregnancy, and poor acoustic window were excluded. Statistical analyses comprised univariate analysis, Wilcoxon signed-rank test, Spearman correlation, and intraclass correlation coefficient. Ethical approval was granted by the institution's ethics committee. RESULTS: A total of 49 critically ill patients were included, predominantly male (63.27%), with a median age of 57 years. Diagnoses included subarachnoid hemorrhage (53.06%) and heart failure (8.16%). Mean cardiac index was 3.36 ± 0.81 L/min/m2 and mean cardiac output was 5.98 ± 1.47 L/min. Spearman correlation coefficient between echocardiography and invasive CO measurements was 0.58 (p-value = p < 0.001), with an ICC of 0.59 for CO and 0.52 for cardiac index. Carotid measurements displayed no significant correlation with invasive CO. CONCLUSION: There is a moderate correlation and concordance between echocardiography and invasive CO measurements. There is no significant correlation between carotid variables and invasive CO, underscoring the necessity for cautious interpretation and application, particularly in patients with distinctive cerebral blood flow dynamics.

Application of a simplified transesophageal echocardiography examination sequence in high-risk cardiac surgery.

BACKGROUND: In cardiac surgical procedures, patients carrying high-risk profiles are prone to encompass complicated cardiopulmonary bypass (CPB) separation. Intraoperative transesophageal echocardiography (TEE), a readily available tool, is utilized to detect cardiac structural and functional pathologies as well as to facilitate clinical management of CPB separation, especially in the episodes of hemodynamic compromise. However, the conventional TEE examination, always performed in a liberal fashion without any restriction of view acquisition, is relatively time-consuming; there appear its flaws in the context of critically severe status. We therefore developed the perioperative rescue transesophageal echocardiography (PReTEE), a simplified three-view TEE protocol consisting of midesophageal four chamber, midesophageal left ventricular long axis, and transgastric short axis. METHODS: This is a single-center and randomized controlled trial which will be implemented in Peking Union Medical College Hospital, Beijing, China. A total of 46 TEE scans are schemed to be performed by 6 operators participating in and randomly assigned to either the PReTEE or the conventional TEE group. This study is purposed to investigate whether the efficiency of discriminating leading causes of difficult CPB wean-off can be significantly improved via an abbreviated sequence of TEE views. The primary outcome of interest is the difference between the groups of PReTEE and the conventional TEE in the successful discrimination of etiologies in specified 120 s. Cox proportional hazards model will be further employed to calculate the outcome difference. DISCUSSION: The estimated results of this trial are oriented at verifying whether a simplified TEE exam sequence can improve the efficiency of etiologies discrimination during CPB separation in cardiac surgery. TRIAL REGISTRATION: ClinicalTrials.gov NCT05960552. Registered on 6 July 2023.

Effects of ischemic pre-conditioning on electrically stimulated contractions.

PURPOSE: Ischemic pre-conditioning (IPC) offers protection against future ischemic events and may improve sports performance due to several mechanisms at local and systemic levels. This study investigates the local effects on muscle contractility in electrically induced muscle contractions, thus effectively excluding any uncontrolled change in the motor drive. METHODS: Twenty-one subjects were divided into two groups: 12 subjects in the IPC group (3 × 5/5 min right arm ischemia/reperfusion; cuff pressure 250 mmHg) and 9 subjects in the SHAM group (same treatment at 20 mmHg). The adductor pollicis was contracted by supramaximal stimulation of the ulnar nerve with single pulses, trains of stimuli (5, 8, 10 and 12 Hz, 1-s duration) and bursts (4 pulses, 25 Hz), all separated by 5-s intervals. The stimulation sequence was delivered before and 15 and 30 min after IPC/SHAM treatment. The isometric contraction force, the superficial electromyographic signal, and tissue oxygenation were continuously monitored. RESULTS: A significant force decrease in time was observed at 8, 10 (p < 0.01) and 12 Hz (p < 0.05) along with a decrease in half-relaxation time in single twitches and bursts (p = 0.01), regardless of treatment. This general time-related weakening was more marked in IPC than SHAM at 5-Hz stimulation. No effects were observed on the magnitude of the superficial electromyographic signal. CONCLUSION: Data indicate that IPC does not increase muscle force during electrically stimulated contractions, supporting the idea that IPC's ergogenic effects are not due to increased muscle contractility.

Computing pulsatile blood flow of coronary artery under incomplete boundary conditions.

BACKGROUND: Accurate measurement of pulsatile blood flow in the coronary arteries enables coronary wave intensity analysis, which can serve as an indicator for assessing coronary artery physiology and myocardial viability. Computational fluid dynamics (CFD) methods integrating coronary angiography images and fractional flow reserve (FFR) offer a novel approach for computing mean coronary blood flow. However, previous methods neglect the inertial effect of blood flow, which may have great impact on pulsatile blood flow calculation. To improve the accuracy of pulsatile blood flow calculation, a novel CFD based method considering the inertia term is proposed. METHODS: A flow resistance model based on Pressure-Flow vs.Time curves is proposed to model the resistance of the epicardial artery. The parameters of the flow resistance model can be fitted from the simulated pulsating flow rates and pressure drops of a specific mode. Then, pulsating blood flow can be calculated by combining the incomplete pressure boundary conditions under pulsating conditions which are easily obtained in clinic. Through simulation experiments, the effectiveness of the proposed method is validated in idealized and reconstructed 3D model of coronary artery. The impacts of key parameters for generating the simulated pulsating flow rates and pressure drops on the accuracy of pulsatile blood flow calculation are also investigated. RESULTS: For the idealized model, the previously proposed Pressure-Flow model has a significant leading effect on the computed blood flow waveform in the moderate model, and this leading effect disappears with the increase of the degree of stenosis. The improved model proposed in this paper has no leading effect, the root mean square error (RMSE) of the proposed model is low (the left coronary mode:≤0.0160, the right coronary mode:≤0.0065) for all simulated models, and the RMSE decreases with an increase of stenosis. The RMSE is consistently small (≤0.0217) as the key parameters of the proposed method vary in a large range. It is verified in the reconstructed model that the proposed model significantly reduces the RMSE of patients with moderate stenosis (the Pressure-Flow model:≤0.0683, the Pressure-Flow vs.Time model:≤0.0297), and the obtained blood flow waveform has a higher coincidence with the simulated reference waveform. CONCLUSIONS: This paper confirms that ignoring the effect of inertia term can significantly affect the accuracy of calculating pulsatile blood flow in moderate stenosis lesions, and the new method proposed in this paper can significantly improves the accuracy of calculating pulsatile blood flow in moderate stenosis lesions. The proposed method provides a convenient clinical method for obtaining pressure-synchronized blood flow, which is expected to facilitate the application of waveform analysis in the diagnosis of coronary artery disease.