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Various non-invasive images are used in clinical practice for the diagnosis and prognostication of chronic coronary syndromes. Notably, quantitative myocardial perfusion imaging (MPI) through positron emission tomography (PET) has seen significant technical advancements and a substantial increase in its use over the past two decades. This progress has generated an unprecedented wealth of clinical information, which, when properly applied, can diagnose and fine-tune the management of patients with different types of ischemic syndromes. This state-of-art review focuses on quantitative PET MPI, its integration into clinical practice, and how it holds up at the eyes of modern cardiac imaging and revascularization clinical trials, along with future perspectives.
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BACKGROUND: Dynamic arterial elastance (Eadyn) has been investigated for its ability to predict hypotension during the weaning of vasopressors. Our study focused on assessing Eadyn's performance in the context of critically ill adult patients admitted to the intensive care unit, regardless of diagnosis. MAIN BODY: Our study was conducted in accordance with the Preferred Reported Items for Systematic Reviews and Meta-Analysis checklist. The protocol was registered in PROSPERO (CRD42023421462) on May 26, 2023. We included prospective observational studies from the MEDLINE and Embase databases through May 2023. Five studies involving 183 patients were included in the quantitative analysis. We extracted data related to patient clinical characteristics, and information about Eadyn measurement methods, results, and norepinephrine dose. Most patients (76%) were diagnosed with septic shock, while the remaining patients required norepinephrine for other reasons. The average pressure responsiveness rate was 36.20%. The synthesized results yielded an area under the curve of 0.85, with a sensitivity of 0.87 (95% CI 0.74-0.93), specificity of 0.76 (95% CI 0.68-0.83), and diagnostic odds ratio of 19.07 (95% CI 8.47-42.92). Subgroup analyses indicated no variations in the Eadyn based on norepinephrine dosage, the Eadyn measurement device, or the Eadyn diagnostic cutoff to predict cessation of vasopressor support. CONCLUSIONS: Eadyn, evaluated through subgroup analyses, demonstrated good predictive ability for the discontinuation of vasopressor support in critically ill patients.
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This study evaluated the relationship between CL features assessed by ultrasound (luteal tissue area and blood flow, BF) or rectal palpation (size), uterine tone (UT), plasma progesterone (P4) concentration on Day 7 (D7) and subsequent pregnancy outcomes in bovine embryo recipients. A total of 163 cows and heifers were included in this study. The expected day of ovulation after the synchronization protocol was designated as D0. On D7, ovaries and uterus were examined by ultrasonography and rectal palpation, and subjective scores (1-3 scale) were assigned for CL size, area and BF, and for UT. Blood samples were collected for further P4 analysis. Each embryo recipient then received a grade I frozen-thawed in vivo-produced blastocyst, which was transferred to the uterine horn ipsilateral to the CL. Pregnancy diagnosis was performed on D35, and the results were retrospectively compared with the assigned scores for CL and UT. We observed a significant (p < .02) interaction between CL size and UT, with a progressive increase in the likelihood of pregnancy for recipients bearing a large CL among those with turgid UT. Ultrasound scoring of the CL using B-mode and Doppler-mode did not significantly predict pregnancy rates on D35 (p < .6 and p < .5, respectively). However, logistic regression analysis revealed a trend towards a quadratic effect (p < .08 and p < .06) indicating that the probability of pregnancy varied according to the area of luteal tissue and P4 concentrations, respectively. No significant (p > .05) association was found between the probability of pregnancy and the BF area of the CL. In summary, UT before embryo transfer may reflect successful recipient synchronization. Elevated P4 levels, assessed by CL size, may offset uterine contractility, mitigating adverse effects. Additionally, the CL area may be more important than its vascularization area when evaluating recipients D7 after ovulation.
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Transferência Embrionária , Progesterona , Útero , Feminino , Animais , Bovinos/fisiologia , Transferência Embrionária/veterinária , Gravidez , Útero/irrigação sanguínea , Útero/diagnóstico por imagem , Progesterona/sangue , Ultrassonografia/veterinária , Corpo Lúteo/fisiologia , Taxa de Gravidez , Sincronização do Estro , Resultado da Gravidez/veterináriaRESUMO
PURPOSE: Central and peripheral chemoreceptors are hypersensitized in patients with heart failure with reduced ejection fraction. Whether this autonomic alteration occurs in patients with heart failure with preserved ejection fraction (HFpEF) remains little known. We test the hypothesis that the central and peripheral chemoreflex control of muscle sympathetic nerve activity (MSNA) is altered in HFpEF. METHODS: Patients aged 55-80 years with symptoms of heart failure, body mass index ≤ 35 kg/m2, left ventricular ejection fraction > 50%, left atrial volume index > 34 mL/m2, left ventricular early diastolic filling velocity and early diastolic tissue velocity of mitral annulus ratio (E/e' index) ≥ 13, and BNP levels > 35 pg/mL were included in the study (HFpEF, n = 9). Patients without heart failure with preserved ejection fraction (non-HFpEF, n = 9), aged-paired, were also included in the study. Peripheral chemoreceptors stimulation (10% O2 and 90% N2, with CO2 titrated) and central chemoreceptors stimulation (7% CO2 and 93% O2) were conducted for 3 min. MSNA was evaluated by microneurography technique, and forearm blood flow (FBF) by venous occlusion plethysmography. RESULTS: During hypoxia, MSNA responses were greater (p < 0.001) and FBF responses were lower in patients with HFpEF (p = 0.006). Likewise, MSNA responses during hypercapnia were higher (p < 0.001) and forearm vascular conductance (FVC) levels were lower (p = 0.030) in patients with HFpEF. CONCLUSIONS: Peripheral and central chemoreflex controls of MSNA are hypersensitized in patients with HFpEF, which seems to contribute to the increase in MSNA in these patients. In addition, peripheral and central chemoreceptors stimulation in patients with HFpEF causes muscle vasoconstriction.
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Células Quimiorreceptoras , Insuficiência Cardíaca , Volume Sistólico , Humanos , Idoso , Masculino , Feminino , Insuficiência Cardíaca/fisiopatologia , Pessoa de Meia-Idade , Volume Sistólico/fisiologia , Células Quimiorreceptoras/fisiologia , Idoso de 80 Anos ou mais , Sistema Nervoso Simpático/fisiopatologia , Músculo Esquelético/fisiopatologiaRESUMO
BACKGROUND: Physics-informed neural networks (PINNs) have emerged as a powerful tool for solving inverse problems, especially in cases where no complete information about the system is known and scatter measurements are available. This is especially useful in hemodynamics since the boundary information is often difficult to model, and high-quality blood flow measurements are generally hard to obtain. METHODS: In this work, we use the PINNs methodology for estimating reduced-order model parameters and the full velocity field from scatter 2D noisy measurements in the aorta. Two different flow regimes, stationary and transient were studied. RESULTS: We show robust and relatively accurate parameter estimations when using the method with simulated data, while the velocity reconstruction accuracy shows dependence on the measurement quality and the flow pattern complexity. Comparison with a Kalman filter approach shows similar results when the number of parameters to be estimated is low to medium. For a higher number of parameters, only PINNs were capable of achieving good results. CONCLUSION: The method opens a door to deep-learning-driven methods in the simulations of complex coupled physical systems.
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Modelos Cardiovasculares , Redes Neurais de Computação , Humanos , Velocidade do Fluxo Sanguíneo/fisiologia , Hemodinâmica/fisiologia , Aorta/fisiologia , Simulação por ComputadorRESUMO
BACKGROUND: Cerebral arteriovenous malformations (AVMs) are complex lesions that can cause hemorrhagic stroke and significant neurological disability. Adenosine induces cardiac standstill and hypotension, which are thought to be useful during cerebral AVM embolization. Herein, we conducted a systematic review and meta-analysis of the technique's safety. METHODS: Following PRISMA guidelines, four databases were queried for studies describing the use of adenosine-assisted embolization of cerebral AVMs. Adenosine-related intraoperative complications, permanent neurological outcomes, morbidity, and mortality assessed the technique's safety. Single proportion analysis under a random-effects model was performed. Heterogeneity was assessed using I² statistics, and publication bias was evaluated through funnel plot analysis and Egger's regression test. RESULTS: Ten studies were included, involving 79 patients (55.7% male) with 79 AVMs (54.4% unruptured and 70.9% Spetzler-Martin grade III-V) who underwent 123 embolizations (80.4% and 5.9% under transarterial and transvenous approaches, respectively) with n-butyl cyanoacrylate (80.4%), ethylene vinyl alcohol (14.4%), or both (5.2%). The incidence of transient adenosine-related intraoperative complications was 0% (95% CI 0% to 3%, I2=24%). Besides, the incidence of adenosine-related morbidity, mortality, and permanent outcomes was 0% (95% CI 0% to 3%, I2=0%). During follow-up, good functional outcomes were reported for 64 patients (81%). CONCLUSIONS: Adenosine's effects on blood flow control can facilitate embolization and mitigate the risk of AVM rupture and embolic agent migration. Although current evidence stems from observational studies, the results of this meta-analysis suggest a safe drug profile due to minimal associated morbidity and mortality. Further research from larger randomized and controlled studies is warranted to attain a higher level of evidence. PROSPERO REGISTRY NUMBER: CRD42023494116.
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BACKGROUND: The prognosis of patients with ST-segment elevation myocardial infarction (STEMI) and previous percutaneous coronary intervention (PCI) is uncertain. OBJECTIVE: To evaluate if previous PCI in patients with STEMI increases the risk of major cardiovascular events, and if final epicardial blood flow differs according to the reperfusion strategy. MATERIAL AND METHODS: Observational, longitudinal, comparative sub-study of the PHASE-MX trial that included patients with STEMI and reperfusion within 12 hours of symptom onset, who were classified according to their history of PCI. The occurrence of the composite primary endpoint (cardiovascular death, re-infarction, congestive heart failure and cardiogenic shock) within 30 days was evaluated using Kaplan-Meier estimates, log-rank test and Cox proportional hazards model. Epicardial blood flow was assessed using the TIMI grading system after reperfusion. RESULTS: A total of 935 patients were included; 85.6% were males and 6.9% had a history of PCI; 53% underwent pharmacoinvasive therapy, and 47%, primary PCI. The incidence of the composite primary endpoint at 30 days in patients with a history of PCI was 9.8% vs 13.3% in those with no previous PCI (p = 0.06). Among the patients with previous PCI, 87.1% reached a final TIMI grade 3 flow after primary PCI vs. 75% in the group with pharmacoinvasive strategy (p = 0.235). CONCLUSIONS: A history of PCI does not increase the risk of major cardiovascular events at 30 days; however, it impacted negatively on the final angiographic blood flow of patients that received pharmacoinvasive therapy (compared to primary PCI).
ANTECEDENTES: El pronóstico de los pacientes con infarto agudo de miocardio con elevación del segmento ST (IAMCEST) y antecedente de intervención coronaria percutánea (ICP) es incierto. Objetivos: Evaluar si la ICP previa en pacientes con IAMCEST incrementa el riesgo de eventos cardiovasculares mayores y si el flujo final epicárdico varía según la estrategia de reperfusión. MATERIAL Y MÉTODOS: Subestudio de PHASE-MX, observacional, longitudinal y comparativo, de pacientes con IAMCEST reperfundidos en menos de 12 horas de iniciados los síntomas, divididos conforme el antecedente de ICP. El acaecimiento del criterio de valoración principal (muerte cardiovascular, reinfarto, insuficiencia cardíaca y choque cardiogénico) dentro de los 30 días se comparó con estimaciones de Kaplan-Meier, prueba de rangos logarítmicos y modelo de riesgos proporcionales de Cox. El flujo epicárdico final se evaluó con el sistema de clasificación del flujo TIMI después de la reperfusión. RESULTADOS: Se incluyeron 935 pacientes, 85.6 % del sexo masculino, 6.9 % de los cuales tenía antecedente de ICP; 53 % recibió terapia farmacoinvasiva y 47 %, ICP primaria. La incidencia del criterio de valoración principal en pacientes con ICP previa fue de 9.8 % versus 13.3 % en aquellos sin ese antecedente (p = 0.06); 87.1 % de los pacientes con ICP previa obtuvo flujo final de grado TIMI 3 versus 75 % del grupo con estrategia farmacoinvasiva (p = 0.235). CONCLUSIONES: El antecedente de ICP no incrementa el riesgo de eventos cardiovasculares mayores a los 30 días en pacientes con IAMCEST; sin embargo, impacta negativamente en el flujo sanguíneo angiográfico final de los pacientes que recibieron terapia farmacoinvasiva (en comparación con ICP primaria).
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Angiografia Coronária , Intervenção Coronária Percutânea , Infarto do Miocárdio com Supradesnível do Segmento ST , Humanos , Intervenção Coronária Percutânea/métodos , Masculino , Feminino , Infarto do Miocárdio com Supradesnível do Segmento ST/terapia , Pessoa de Meia-Idade , Idoso , Estudos Longitudinais , Resultado do Tratamento , Prognóstico , Estimativa de Kaplan-Meier , Modelos de Riscos ProporcionaisRESUMO
Most of the responses present in animals when exposed to stressors are mediated by the autonomic nervous system. The sympathetic nervous system, known as the one responsible for the "fight or flight" reaction, triggers cardiovascular changes such as tachycardia or vasomotor alterations to restore homeostasis. Increase in body temperature in stressed animals also activates peripheral compensatory mechanisms such as cutaneous vasodilation to increase heat exchange. Since changes in skin blood flow influence the amount of heat dissipation, infrared thermography is suggested as a tool that can detect said changes. The present review aims to analyze the application of infrared thermography as a method to assess stress-related autonomic activity, and their association with the cardiovascular and heart rate variability in domestic animals.
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BACKGROUND: Blood flow restriction (BFR) combined with low-load resistance training could minimize exercise barriers and offer strength and mobility improvements for people with advanced Multiple Sclerosis (MS); but patient experience has not been evaluated. PURPOSE: The purpose of this study was to assess the satisfaction, acceptability, and impact of combining low-load resistance training with BFR for individuals with advanced MS (Expanded Disability Status Scale: EDSS 6.0-7.0). METHODS: We used an interpretive phenomenological research design and post-intervention interviews to explore participant experiences of a novel low-load resistance training program with BFR. RESULTS: Interview participants (n = 14) were 55.4 ± 6.2 years old and were diagnosed with MS for 19.1 ± 10.7 years. Four themes were identified (satisfaction, acceptability, impact, program refinement) with 14 subthemes. Satisfaction was mixed based on overall expectations, yet all participants recommended the intervention. Acceptability was evidenced by all participants identifying comfortable/easy aspects, and modifiable elements that could improve comfort. Impact was evidenced with translation to everyday life activities, strength/self-efficacy/psychological improvements, effectiveness, and fatigue reduction. CONCLUSIONS: Participants found BFR combined with low-load resistance training to be satisfactory (mixed initial expectations), acceptable (comfortable/easy), and impactful (translating to life improvements). Areas for program refinement were identified that should be targeted in future iterations.