RESUMO
The presence of cardiac shunts in ectothermic tetrapods is thought to be consistent with active vascular modulations for proper hemodynamic support. Local control of blood flow modulates tissue perfusion and thus systemic conductance (Gsys) is assumed to increase with body temperature (Tb) to accommodate higher aerobic demand. However, the general increase of Gsys presses for a higher right-to-left (R-L) shunt, which reduces arterial oxygen concentration. In contrast, Tb reduction leads to a Gsys decrease and a left-to-right shunt, which purportedly increases pulmonary perfusion and plasma filtration in the respiratory area. This investigation addressed the role of compensatory vascular adjustments in the face of the metabolic alterations caused by Tb change in the South American rattlesnake (Crotalus durissus). Cardiovascular recordings were performed in decerebrated rattlesnake preparations at 10, 20 and 30°C. The rise in Tb increased metabolic demand, and correlated with an augmentation in heart rate. Although cardiac output increased, systemic stroke volume reduced while pulmonary stroke volume remained stable. Although that resulted in a proportionally higher increase in pulmonary blood flow, the R-L shunt was maintained. While the systemic compliance of large arteries was the most relevant factor in regulating arterial systemic blood pressure, peripheral conductance of pulmonary circulation was the major factor influencing the final cardiac shunt. Such dynamic adjustment of systemic compliance and pulmonary resistance for shunt modulation has not been demonstrated before and contrasts with previous knowledge on shunt control.
Assuntos
Crotalus , Hemodinâmica , Animais , Crotalus/fisiologia , Temperatura Corporal/fisiologia , Frequência Cardíaca/fisiologia , Temperatura , Débito Cardíaco/fisiologia , Circulação Pulmonar/fisiologia , Masculino , Serpentes PeçonhentasRESUMO
Scimitar Syndrome is part of a complex spectrum of congenital cardiovascular anomalies related to anomalous pulmonary venous return. Depending on the extent of involvement, treatment can be either expectant or surgical. Prognosis and survival have been controversial, with some results supporting early surgical management. This research aims to disclose the outcomes and describe the management, clinical and imaging characteristics of patients diagnosed with Scimitar Syndrome treated in a tertiary referral healthcare center. Longitudinal descriptive observational study. The study included all patients diagnosed with scimitar syndrome in our institution between January/2011 and December/2022. A description of the sociodemographic and clinical characteristics, diagnostic tools used, treatment features, and patient outcomes is provided. Eleven patients were included, with a mean age at diagnosis of five years (CI 0-17), six of which were female (54.55%). Nine (81.82%) patients had evidence of a scimitar vein on the chest radiograph, six (54.55%) cardiac dextroposition, six (54.55%) pulmonary hypoplasia, five (45.45%) right pulmonary artery hypoplasia, and three (27.27%) had aortopulmonary collaterals. Four (36.36%) patients had horseshoe lungs, and four (36.36%) had bronchopulmonary sequestration. In the associations, two (18.18%) patients were found to have an atrial septal defect, three (27.27%) ventricular septal defect, and one (9%) had Tetralogy of Fallot. Pulmonary hypertension was demonstrated in two (18.18%) patients. Seven (63.64%) required surgical management to correct the scimitar vein, and two patients died due to unrelated complications. Scimitar syndrome presents diagnostic and treatment challenges, necessitating a multidisciplinary approach for timely care. Chest radiography and CT scans are primary diagnostic tools, with surgical intervention often warranted alongside other heart defects or significant hemodynamic repercussions. Medical management is effective for mild to moderate cases. Long-term patient outcomes remain uncertain due to study limitations, but improved life expectancy is anticipated with ongoing care.
Assuntos
Valor Preditivo dos Testes , Síndrome de Cimitarra , Centros de Atenção Terciária , Humanos , Síndrome de Cimitarra/diagnóstico por imagem , Síndrome de Cimitarra/cirurgia , Síndrome de Cimitarra/fisiopatologia , Síndrome de Cimitarra/mortalidade , Síndrome de Cimitarra/terapia , Feminino , Masculino , Colômbia , Pré-Escolar , Criança , Lactente , Adolescente , Resultado do Tratamento , Recém-Nascido , Estudos Longitudinais , Fatores de Tempo , Estudos Retrospectivos , Circulação Pulmonar , Procedimentos Cirúrgicos CardíacosRESUMO
El pulmón recibe sangre desde la circulación bronquial y pulmonar. La circulación pulmonar presenta importantes diferencias con la sistémica, sus vasos sanguíneos poseen características únicas que le permiten cumplir sus diferentes funciones, siendo la más importante el intercambio gaseoso. Existen múltiples factores, activos y pasivos, que están involucrados en la regulación de la resistencia vascular y flujo sanguíneo pulmonar.
The lung receives blood from the bronchial and the pulmonary circulation. The pulmonary circulation presents important differences with the systemic circulation, its blood vessels have unique characteristics that allow them to fulfill their different functions, the most important being gas exchange. There are multiple factors, active and passive, that are involved in the regulation of vascular resistance and pulmonary blood flow.
Assuntos
Humanos , Circulação Pulmonar/fisiologia , Fenômenos Fisiológicos Respiratórios , Resistência Vascular/fisiologia , Vasos Sanguíneos/anatomia & histologia , Pulmão/irrigação sanguíneaRESUMO
Introducción: en las grandes altitudes, el intercambio gaseoso suele estar deteriorado; en la altitud moderada de la Ciudad de México esto no está aún plenamente definido. Objetivo: caracterizar el intercambio gaseoso en la altitud moderada de la Ciudad de México. Material y métodos: mediante un estudio transversal analítico se estudiaron sujetos nacidos y habitantes de la Ciudad de México, de ambos géneros, con edades de 20 a 59 años sin enfermedad cardiopulmonar. Se registraron sus variables demográficas, espirometría simple y de gasometría arterial. Las diferencias en las variables se calcularon con ANOVA de una vía para grupos independientes y ajuste de Bonferroni. Una p < 0.05 se aceptó como significativa. Resultados: se estudiaron 335 sujetos, de los cuales 168 (50.15%) fueron hombres, la edad grupal fue de 45 ± 11 años, con índice de masa corporal 22.97 ± 1.54 Kg/m2. La relación volumen espiratorio forzado en el primer segundo/Capacidad vital forzada (VEF1/CVF) de 91.58 ± 12.86%. La presión arterial de oxígeno fue de 66 ± 5.02 mmHg, el bióxido de carbono: 32.07 ± 2.66 mmHg, la saturación arterial de oxígeno: 93.03 ± 1.80% y la hemoglobina: 14.07 ± 1.52 gr/dL. Conclusiones: la presión arterial de oxígeno y del bióxido de carbono están disminuidos a la altura de la Ciudad de México.
Background: At high altitude the gas exchange is impaired, in the moderate altitude of Mexico City they are not yet defined. Objective: To characterize the gas exchange in the moderate altitude of Mexico City. Material and methods: Through an analytical cross-sectional study, subjects born and inhabitants of Mexico City, both genders, aged 20 to 59 years without cardiopulmonary disease, were studied. Their demographic variables, simple spirometry and arterial blood gas were recorded. Differences in variables were calculated with one-way ANOVA for independent groups and Bonferroni adjustment. p < 0.05 was accepted as significant. Results: 335 subjects were studied, 168 (50.15%) men. Group age 45 ± 11 years old, body mass index 22.97 ± 1.54 Kg/m2. Forced expiratory volume ratio in the first second / Forced vital capacity (FEV1/FVC) 91.58 ± 12.86%. The arterial oxygen pressure was: 66 ± 5.02 mmHg, carbon dioxide: 32.07 ± 2.66 mmHg, arterial oxygen saturation: 93.0 3 ± 1.80%, and hemoglobin: 14.07 ± 1.52 gr/dL. Conclusions: The arterial oxygen pressure and carbon dioxide are lowered at the Mexico City altitude.
Assuntos
Humanos , Masculino , Feminino , Doença Cardiopulmonar , Gasometria , Pressão Arterial , Testes de Função Respiratória , Espirometria , Volume Expiratório Forçado , Circulação Pulmonar , Estudos Transversais , Fenômenos Fisiológicos Circulatórios e RespiratóriosRESUMO
INTRODUCTION: Ductus arteriosus stenting is a palliative alternative for neonates with ductal-dependent pulmonary flow. OBJECTIVE: To present an alternative of arterial access for percutaneous coronary intervention in neonates. CLINICAL CASE: A term neonate with low weight diagnosed with pulmonary atresia with intact ventricular septum and severe hypoplasia of the tricuspid valve with dependent coronary circu lation. Due to the surgical risk and femoral artery damage and the anatomy of the ductus arteriosus, a left axillary arterial puncture was decided where a 3.5-millimeter coronary stent was successfully placed. The patient developed an axillary spasm that resolved spontaneously. CONCLUSION: Alternati ve arterial access other than the femoral artery route is an option for neonates with high surgical risk and low birth weight.
Assuntos
Artéria Axilar/cirurgia , Stents Farmacológicos , Canal Arterial , Implantação de Prótese/métodos , Atresia Pulmonar/complicações , Circulação Pulmonar , Aorta Torácica/diagnóstico por imagem , Cateterismo Cardíaco/métodos , Circulação Coronária , Canal Arterial/diagnóstico por imagem , Humanos , Recém-Nascido de Baixo Peso , Recém-Nascido , Masculino , Implantação de Prótese/efeitos adversos , Punções , Valva Tricúspide/anormalidadesRESUMO
Chronic exposure to altitude has been associated with hypobaric hypoxia in its inhabitants. Two entities have been associated with it, high altitude pulmonary hypertension and chronic mountain sickness. Its physiological and pulmonary circulation characteristics are described, as well as its clinical profile and diagnosis.
La exposición crónica a la altitud se ha asociado a hipoxia hipobárica en quienes la experimentan. Dos entidades se han asociado a la hipoxia hipobárica: la hipertensión pulmonar de la alta altitud y el mal de montaña crónico. Se describen sus características fisiológicas y de la circulación pulmonar, así como su perfil clínico y el diagnóstico.
Assuntos
Doença da Altitude/fisiopatologia , Hipertensão Pulmonar/fisiopatologia , Hipóxia/etiologia , Circulação Pulmonar/fisiologia , Altitude , Doença da Altitude/diagnóstico , Doença da Altitude/etiologia , Humanos , Hipertensão Pulmonar/complicações , Hipertrofia Ventricular Direita , Hipóxia/diagnóstico , Hipóxia/fisiopatologia , Fatores de RiscoRESUMO
PURPOSE: The mechanisms of brain metastasis are incompletely understood. Circulating tumor cells travel to the right heart and through the pulmonary circulation, where they may become lung metastases, and can circulate further to the left heart and brain. In patients who develop brain metastases without lung involvement, we hypothesized that cancer cells may travel directly from the right atrium to left atrium via a patent foramen ovale (PFO), akin to paradoxical embolism. If the prevalence of PFO is greater in these individuals compared to the general population (20-30%), PFO may play a role in brain metastasis, and prophylactic closure may provide benefit. Accordingly, we investigated the prevalence of PFO in patients with brain metastases without prior lung involvement. METHODS: We prospectively identified patients with brain metastases from a non-lung primary cancer with no preceding or concurrent lung involvement. Nine eligible participants underwent a transcranial Doppler study with intravenous agitated saline to assess for PFO. RESULTS: Among nine participants, primary cancers were breast (n = 6), upper gastrointestinal (n = 2), and thyroid (n = 1). A positive bubble study was identified in 2/9 (22.2%) participants: one female with breast cancer and one male with duodenal adenocarcinoma. No participants developed lung metastases on subsequent chest imaging. CONCLUSION: In this prospective pilot study, we found a similar prevalence of PFO in patients who developed brain metastases without preceding lung involvement compared to estimates for the general population. Through a larger study is needed, the development of brain metastases in these individuals may primarily reflect tumor-specific biological factors diecting metastasis organotropism.