Fisiología respiratoria: el pulmón al momento de nacer / Respiratory Physiology - the lung at the moment of birth

La adaptación fisiológica de los recién nacidos de la vida intrauterina a la extrauterina incluye cambios fisiológicos complejos. Para que se complete con éxito la transición fetal a neonatal, los recién nacidos deben lograr el aclaramiento de líquido pulmonar, la generación de CRF e inicio de la respiración, para permitir el intercambio de gases y la oxigenación de los tejidos. En este artículo se describen estos mecanismos, algunas bases del desarrollo pulmonar y de la circulación fetal; y las medidas que se requieren para asistir al recién nacido cuando no logran completar esta transición espontáneamente, lo que ocurre en el 5 al 10 % de los casos.

The physiological adaptation of newborns from intrauterine to extrauterine life includes complex physiological changes. For the fetal to neonatal transition to be successfully completed, neonates must achieve lung fluid clearance, FRC generation, and initiation of respiration to allow gas exchange and tissue oxygenation. This article describes these mechanisms, some bases of lung development and fetal circulation; and the measures required to assist the newborn, when they fail to complete this transition spontaneously, which occurs in the 5 to 10% of cases.

Denervação simpática renal no tratamento da hipertensão arterial resistente: relato de caso / Renal sympathetic denervation in the treatment of resistant arterial hypertension: case report

Introdução: A hipertensão arterial sistêmica (HAS) pode levar a consequências cardiovasculares graves quando não tratadas adequadamente. No entanto, alguns indivíduos, mesmo realizando tratamento recomendado, a pressão arterial (PA) se mantém elevada, passando a ser chamada de hipertensão arterial refratária (HAR). A denervação simpática renal (DSR) é uma terapia amplamente estuda e com resultados promissores que surgiu como alternativa para controlar a PA em pacientes resistentes ao tratamento convencional. Relato de caso: Participante da pesquisa, sexo masculino, 67 anos, com queixa de cefaleia e elevação dos níveis pressóricos. Avaliação cardíaca com alteração apenas da PA (182x113 mmHg), demais sistemas sem variações. Diagnosticado com HAS estágio 3, realizou todas as etapas do tratamento medicamentoso, porém resistente as terapias propostas. Diante do caso, foi diagnosticado com HAR. Sendo realizado DSR que mostrou resultados satisfatórios de redução progressiva da pressão arterial central e periférica. Conclusão: A DSR mostrou-se eficaz no controle gradual e sustentado da PA do participante da pesquisa. Contudo, somente através de estudos clínicos mais amplos e rigorosos será capaz de comprovar a eficácia da DSR no tratamento da PA alta persistente (AU).

Introduction: Systemic arterial hypertension (SHT) can lead to severe cardiovascular outcomes when not properly treated. However, in some individuals, even with recommended treatment, blood pressure (BP) remains high, and is now referred to as Resistant hypertension (RHTN). Renal sympathetic denervation (RDn) is a widely studied and promising therapy that has emerged as an alternative to control BP in patients resistant to conventional treatment. Case report: Research participant, male, 67 years old, complaining of headache and elevated blood pressure. Cardiac assessment with only BP alteration (182x113 mmHg), other systems without variations. Diagnosed with stage 3 hypertension, performed all stages of drug treatment, but resistant to the proposed therapies. Given the case, was diagnosed with RHTN. Being performed RDn that showed satisfactory results of progressive reduction of central and peripheral blood pressure. Discussion: Sympathetic hyperactivity of the renal nervous system releases catecholamines that raise BP. Based on this, the RDn uses a catheter connected to the radiofrequency device that through the femoral artery goes to the two renal arteries and emits energy in the sympathetic fibers attached to the walls of these arteries, destroying them. RDn has been the target of several clinical studies, the best-known being Simplicity HTN-1, 2 and 3 which brought significant and questionable results regarding the efficacy of the procedure. Conclusion: RDn proved to be effective in gradually and sustained BP control of the research participant. However, only through broader and more rigorous clinical studies will it be able to prove the efficacy of RDn in combating persistent high BP (AU).

Fisiología respiratoria: circulación pulmonar / Respiratory physiology: pulmonary circulation

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.

Uterine vascular resistance and other maternal factors associated with the risk of developing hypertension during pregnancy

Gestational hypertension and pre-eclampsia are important causes of perinatal morbidity. The objective of the present study was to determine the increase in relative risk for developing hypertensive disorders of pregnancy based on the evaluation of pregnant women between 20 and 25 weeks of gestation, and to correlate the findings at this period with the outcome of pregnancy. We conducted a prospective cohort study, with a convenience sample of 1417 patients evaluated at this gestational age, of which 1306 were contacted at childbirth. We detected an increased relative risk of 2.69 (95%CI: 1.86 to 3.89) associated with pulsatility index of the uterine arteries, a 2.8 increase (95%CI: 1.58 to 5.03) in relative risk attributed to maternal age above 35 years, a 1.68 increase (95%CI: 1.17 to 2.40) attributed to parity greater than or equal to 3, and a 5.35 increase (95%CI: 4.18 to 6.85) attributed to chronic hypertension and obesity, with a progressive increase in relative risk according to the degree of overweight, i.e., grades 1, 2, 3, and morbid obesity (2.58, 3.06, 5.84, and 7.28, respectively).

Fístula arteriovenosa como tratamento adjunto na revascularização arterial do membro em risco / Arteriovenous fistula as adjuvant treatment in arterial revascularization of an at-risk limb

Resumo A oclusão arterial aguda do membro inferior continua sendo um grande desafio para o cirurgião vascular. A abordagem cirúrgica depende principalmente da gravidade da lesão tecidual e da duração dos sintomas. Diversas técnicas estão disponíveis no arsenal terapêutico atual; porém, independentemente da técnica escolhida, fatores pós-operatórios, como o escoamento arterial limitado e o baixo fluxo nos substitutos arteriais, podem contribuir negativamente no resultado da revascularização. Descrevemos um caso de oclusão arterial aguda de membro inferior, no pós-operatório de uma derivação femorotibial, que se encontrava ocluída devido a limitação de escoamento e a alta resistência vascular periférica. Foi submetido a nova revascularização femorotibial, associada à confecção de uma fístula arteriovenosa, seguido de amputação de antepé e enxerto parcial de pele. O investimento enérgico no membro em risco possibilita reduzir os desfechos desfavoráveis, como amputação e óbito, e acelera a recuperação dos tecidos acometidos pela isquemia aguda.

Abstract Acute arterial occlusion remains a major challenge for the vascular surgeon. The therapeutic approach depends mostly upon the severity of the tissue injury and the duration of symptoms. Several techniques are available in the current therapeutic arsenal, however, regardless of the technique chosen, postoperative factors frequently observed, such as poor outflow status, or even low graft flow, can contribute negatively to the outcome of revascularization. We describe a case of acute limb ischemia, in the postoperative period of a femoral-tibial bypass, which was occluded due to outflow limitation and high peripheral vascular resistance. The patient underwent a second tibial revascularization combined with construction of an arteriovenous fistula, followed by forefoot amputation and partial skin graft. An energetic approach to the at-risk limb makes it possible to reduce unfavorable outcomes, such as amputation and death, and accelerates recovery of tissues affected by acute ischemia.

Prevalencia de disfunción diastólica de acuerdo con las guías diagnósticas de 2009 y 2016. Relación con la valoración hemodinámica no invasiva / Prevalence of diastolic dysfunction (DD) according to the diagnostic guidelines of 2009 and 2016. Relationship with non-invasive hemodynamic assessment

Resumen Objetivos: Evaluar la prevalencia de DD de acuerdo con los criterios de las guías del 2009 y 2016, y su relación con la distensibilidad arterial sistémica (DAS) y la resistencia vascular periférica (RVP). Material y métodos: Se analizó a 306 pacientes ≥ 40 años de edad, con fracción de expulsión ≥ 50%. Se calcularon en todos DAS y RVP. Resultados: La prevalencia de DD fue de 32.7% y 22.9% según las guías de 2009 y 2016, respectivamente (p = < 0.0001). De acuerdo con las guías del 2009, los pacientes con DD presentaron una media de DAS menor que aquéllos con función normal (p = 0.0001), de modo similar a las guías del 2016 (p = 0.0007). La DD, según las guías de 2009 y 2016, mostró valores más altos de RVP que los normales (p = 0.005 y p = 0.018, respectivamente). Asimismo, la DD fue predictora, en el análisis univariado, de DAS < 0.60 ml.mm Hg-1 y RVP > 1,400 mmHg.min.l-1 según ambas guías. En el análisis multivariado, la DD, de acuerdo con las guías del 2009, persistió como predictor independiente de RVP > 1,400 mmHg.min.l-1. Conclusión: Las guías del 2016 reducen la prevalencia de DD. Ésta, tanto en las guías del 2009 como en las del 2106, fue predictor univariado de DAS < 0.60 ml.mmHg-1 y RVP > 1,400 mmHg.min.l-1. La DD, de acuerdo con las guías de 2009, resultó predictora independiente de RVP > 1,400 mmHg.min.l-1.

Abstract Objectives: To assess the prevalence of developmental disabilities (DD) according to the criteria of the 2009 and 2016 guidelines, and its association with systemic arterial compliance (DAS) and peripheral vascular resistance (RVP). Material and methods: 306 patients aged ≥ 40 years, with ejection fraction ≥ 50% were analyzed. It was estimated in all DAS and RVP. Results: The prevalence of DD was 32.7% and 22.9% according to the 2009 and 2016 guidelines, respectively (p ≤ 0.0001). Patients with DD according to the 2009 guideline had a lower average of DAS than those with normal function (p = 0.0001). Similar with the 2016 guide (p = 0.0007). The presence of DD according to the 2009 and 2016 guideline showed higher RVP values than normal values (p = 0.005 and p = 0.018, respectively). The DD according to both guidelines was a predictor, in the univariate analysis, of DAS < 0.60 ml.mmHg−1 and RVP > 1400 mmHg.min.l−1. The DD according to the 2009 guideline persisted as an independent predictor, in the multivariate analysis, of RVP > 1400 mmHg.min.l−1. Conclusion: The 2016 guide decreases the prevalence of DD. The DD, both from the 2009 and 2106 guidelines, were univariate predictors of DAS <0.60 ml.mmHg−1 and RVP > 1400 mmHg.min.l−1. The DD according to the 2009 guide, was an independent predictor of RVP > 1400 mmHg.min.l−1.

Valores ecobiométricos e índice de resistividade da artéria oftálmica externa em catetos (Tayassu tajacu, Linnaeus, 1758) / [Ecobiometric values and resistivity index of the external ophthalmic artery in collared peccaries (Tayassu tajacu Linnaeus, 1758)]

Foram avaliados ultrassonograficamente, pela via transpalpebral, 28 bulbos oculares de 14 catetos adultos, através de técnica padronizada pelo operador. Adicionalmente foi realizado o estudo hemodinâmico da artéria oftálmica externa pela técnica de Doppler colorido. Os dados coletados foram analisados estatisticamente pelo programa Bioestat 5.0 for Windows, adotando-se 5% de significância. Com a metodologia empregada, obtiveram-se os seguintes valores para os globos oculares direito e esquerdo, respectivamente D1: 1,72 ± 0,29mm e 1,76 ± 0,40mm; D2: 9,95 ± 1,08mm e 10,6 ± 0,99mm; D3: 7,42 ± 0,93mm e 7,45 ± 0,72mm e D4: 17,6 ± 0,78mm e 17,8 ± 0,59mm. Os valores médios do índice de resistividade da artéria oftálmica externa foram 0,435 ± 0,02 e 0,448 ± 0,02 (globos oculares direito e esquerdo, respectivamente). Não houve diferença estatística quanto aos antímeros oculares em nenhum dos parâmetros estudados. Conclui-se que a ecobiometria ocular e a Dopplerfluxometria da artéria oftálmica na espécie Tayassu tajacu é executável e reprodutível, desde que haja domínio do examinador em relação à anatomia e à técnica adequada. Os valores inferidos neste estudo servem de referência para médicos veterinários no diagnóstico de doenças oculares.(AU)

Twenty-eight ocular bulbs of fourteen adult catheters were evaluated through ultrasound with the transpalpebral approach, using a standardized technique by the operator. Additionally, the hemodynamic study of the external ophthalmic artery was performed using the color Doppler technique. The collected data were statistically analyzed by the Bioestat 5.0 for Windows program, adopting 5% of significance. With the methodology employed, the following values were obtained for the right and left eyeballs, respectively D1: 1.72 ± 0.29mm and 1.76 ± 0.40mm; D2: 9.95 ± 1.08mm and 10.6 ± 0.99mm; D3: 7.42 ± 0.93mm and 7.45 ± 0.72mm and D4: 17.6 ± 0.78mm and 17.8 ± 0.59mm. The mean resistivity index values of the external ophthalmic artery were 0.435 ± 0.02 and 0.448 ± 0.02 (right and left eyeball respectively). There was no statistical difference regarding ocular antimers in any of the studied parameters. We concluded that ocular echobiometry and ophthalmic artery Doppler flowmetry in Tayassu tajacu species is executable and reproducible, provided there is an examiner's domain regarding the anatomy and proper technique. The values inferred in this study serve as a reference for veterinarians in the diagnosis of eye diseases.(AU)

Valoración de ecuaciones derivadas del flujo pulmonar y regurgitación tricuspídea: utilidad en el test de vasoreactividad pulmonar / Valuation of equations derived from Pulmonary Flow and Tricuspid Regurgitation: usefulness in Pulmonary Vasoreactivity Testing

RESUMEN: Antecedentes: La presión media arterial pulmonar (PMAP) es una variable hemodinámica indispensable para el diagnóstico, clasificación y pronóstico de la Hipertensión Pulmonar (HP). Su cuantificación se realiza en forma invasiva por cateterismo cardíaco derecho (CCD) y no invasivamente por ecocardiografía Doppler. Masuyama propuso su medición mediante el gradiente transvalvular pulmonar diastólico derivado de la velocidad máxima inicial de la regurgitación pulmonar (∆RPi2) correspondiendo cercanamente a la medición invasiva. Objetivos: Revalidar 3 métodos ecocardiográficos que estiman la PMAP y valorar la utilidad del método de Chemla en el Test de Reactividad Vascular Pulmonar (TRVP). Métodos: Estudio prospectivo, observacional, doble ciego divido en dos etapas. A) o I) 30 pacientes se realizó ecocardiografía Doppler diagnóstica en nuestro centro. Se midieron regurgitación tricuspídea (RT) y tiempo de aceleración pulmonar (TAP) para derivar las siguientes ecuaciones: 1) 0.61xPSAP+1.95 (Chemla) 2) Gradiente presión media RT (∆PmRT) +PAD (presión-aurícula derecha) (Aduen) y 3) 79-0.45xTAP o 90-0.60xTAP, según sea el valor del TAP. B) o II) 10 pacientes enrolados para realizar el TRVP comparando la medición ecocardiográfica (Chemla) con CCD. Resultados: En la primera parte del estudio se encontró alta correlación entre las 3 ecuaciones: ChemlaAduen, R2=0.91; Chemla-Kitabatake, R2=0.87; Aduen-Kitabatake, R2=0,91. En la segunda parte comparando la PMAP-Chemla y Cateterismo derecho (CD) obtuvimos alta correlación: en tiempo 0, 30 min y recuperación:(R2=0.87, 0.99, 0.98, respectivamente). Ambas partes del estudio mostraron límites de concordancia satisfactoria con valor medio de la diferencia entre los métodos cercano a 1 en el t30 y tR del TRVP. Conclusión: los métodos dependientes de la medición de la RT son efectivos y confiables para estimar la PMAP. El método de Chemla es útil en el TRVP.

ABSTRACTS: Background: Mean Pulmonary arterial pressure (PMAP)is an indispensable hemodynamic variable for the diagnosis, classification and prognosis of Pulmonary Hypertension (PH). Its quantification is performed invasively by cardiac catheterization and non-invasively by Doppler echocardiography. Masuyama proposed its measurement by the transvalvular diastolic pulmonary gradient derived from the initial maximum velocity of pulmonary regurgitation(ΔPRi2) corresponding closely to the invasive measurement. Objectives: to compare 3 known echocardiographic methods to estimate MPAP and demonstrate the usefulness of the Chemla method in the Pulmonary Vascular Reactivity Test (PVRT). Methods: prospective, observational, double-blind study divided into two stages. A) 30 patients underwent diagnostic Doppler echocardiography. Tricuspid regurgitation (TR) and pulmonary acceleration time (PAT) were measured to derive the equations: 1) 0.61xSPAP + 1.95 (Chemla) 2) Gradient mean pressure TR (ΔPmTR) + RAP (right atrium pressure) (Aduen).3) 79-0.45xPAT o 90-0.60xPAT depending on the value of PAT. B) 10 patients enrolled to PVRT comparing the echocardiographic measurement (Chemla) with right catheterization. Results: in the first part of the study a high correlation between the 3 equations was found : ChemlaAduen, R2 = 0.91; Chemla-Kitabatake, R2=0.87; Aduen-Kitabatake, R2=0.91. In the second part comparing the MPAP-Chemla and RHC we obtained a high correlation in time 0, 30 min and recovery: (R2=0.87,0,99,0.98, respectively). Both parts of the study showed satisfactory limits concordance with mean value of the difference between the methods close to 1 in the t30 and tR of the TRVP. Conclusion: the methods dependent on the measurement of the TR are effective and reliable for estimating MPAP. The Chemla method is useful in the PVRT.

Anxiety increases the blood pressure response during exercise

Aim: The hypothesis that higher levels of anxiety promote greater blood pressure (BP) responses during physical exercise is tested. The hypothesis that metaborreflex response is increased in an anxious individual is tested as well. Methods: There were 43 volunteers divided by anxiety level: 12 volunteers with mild, moderate and severe symptoms (anxious-group) and 31 volunteers with a minimum level of anxiety (control-group). Arterial BP, heart rate, and forearm blood flow were measured simultaneously during handgrip exercise and post-exercise ischemia, and forearm vascular resistance (FVR) was calculated. Results: Anxious group present higher systolic, diastolic and mean BP at rest when compared with control group (130±11 vs. 122±12 mmHg, p=0.048; 70±6 vs. 65±8 mmHg, p=0.033; 90±7 vs. 84±9 mmHg, p=0.033, respectively) and higher response of systolic, diastolic and mean BP and FVR during exercise when compared with control group (20±9 vs. 13±7 mmHg, p=0.009; 17±8 vs. 11±6 mmHg, p=0.006; 18±8 vs. 11±6 mmHg, p=0.005; and 0±13 vs. -7±9 units, p=0,003, respectively). During post-exercise ischemia, the anxious group also present higher response of diastolic BP, mean BP and FVR when compared with a control group (11±12 vs. 3±4 mmHg, p=0,001, 10±8 vs. 3±5 mmHg, p=0,002; 9±11 vs. -2± 8 units, p=0,03, respectively). Conclusion: Anxious individuals present higher BP responses during physical exercise when compared with those with minimal anxiety symptoms. This increased response may be explained, in part, by increased peripheral vascular resistance due to the greater metaborreflex response.(AU)

Uso de ecocardiografia junto ao leito para medir índices cardíaco e de resistência vascular sistêmica em pacientes pediátricos com choque séptico / The use of bedside echocardiography for measuring cardiac index and systemic vascular resistance in pediatric patients with septic shock

RESUMO Objetivo: Acompanhar o índice cardíaco e o índice de resistência vascular sistêmica até a ressuscitação. Métodos: Por meio de ecocardiografia junto ao leito, obteve-se um conjunto de parâmetros hemodinâmicos, inclusive débito cardíaco, volume sistólico, índice cardíaco, índice de resistência vascular sistêmica, integral velocidade-tempo, índice de desempenho miocárdico, tempo de reenchimento capilar e frequência cardíaca no momento zero após infusão de fluidos em bolo, e início e utilização de fármacos inotrópicos, com seguimento até 6 horas e 24 horas. Resultados: Incluíram-se 45 pacientes com choque séptico adquirido na comunidade. Os focos de infecção foram gastrenterite (24%), perfuração intestinal com necessidade de cirurgia emergencial (24%), pneumonia (20%), infecção do sistema nervoso central (22%) e infecção de tecidos moles (8%). Os isolados mais frequentes foram de Klebsiella e Enterobacter. Estimamos os fatores que afetaram o índice cardíaco: pressão venosa central elevada no momento zero (r = 0,33; p = 0,024) e persistência de frequência cardíaca elevada após 6 horas (r = 0,33; p = 0,03). O índice de resistência vascular sistêmica foi alto na maioria dos pacientes no momento zero e após 24 horas, e por ocasião da ressuscitação, afetando inversamente o índice cardíaco, assim como a integral velocidade-tempo (r = -0,416; -0,61; 0,55 e -0,295). O tempo de reenchimento capilar aumentado foi preditor clínico de valores baixos de integral velocidade-tempo após 24 horas (r = -0,4). O índice de mortalidade foi de 27%. Nos pacientes que não sobreviveram, observaram-se índices de resistência vascular sistêmica mais baixos e débitos cardíacos mais altos. Conclusão: O índice de resistência vascular sistêmica esteve persistentemente elevado em pacientes com choque frio, o que influenciou no índice de volume sistólico, no índice cardíaco e na integral velocidade-tempo. O uso de ecocardiografia para obtenção de mensurações hemodinâmicas é importante em pacientes pediátricos com choque séptico, para que se possam ajustar as doses de vasodilatadores e vasopressores, e obter os objetivos da ressuscitação em tempo apropriado.

ABSTRACT Objective: Follow-up of cardiac index and systemic vascular resistance index by bedside echocardiography until resuscitation. Methods: A set of hemodynamic parameters was obtained, including cardiac output, stroke volume, cardiac index, systemic vascular resistance index, velocity time integral, myocardial performance index, capillary refill time, and heart rate at 0 hours after fluid boluses before the start of inotropes, and followed up after 6 hours and 24 hours. Results: Included were 45 patients with community-acquired septic shock. Septic foci were gastroenteritis (24%), intestinal perforation requiring emergency surgery (24%), pneumonia (20%), central nervous system infection (22%) and soft tissue infection (8%). Klebsiella and Enterobacter were the most frequent isolates. We estimated the factors affecting the cardiac index: high central venous pressure at zero time (r = 0.33, p = 0.024) and persistently high heart rate at hour 6 (r = 0.33, p = 0.03). The systemic vascular resistance index was high in most patients at 0 and 24 hours and at the time of resuscitation and inversely affected the cardiac index as well as affecting the velocity time integral (r = -0.416, -0.61, 0.55 and -0.295). Prolonged capillary refill time was a clinical predictor of the low velocity time integral at 24 hours (r = -0.4). The mortality was 27%. Lower systemic vascular resistance index and higher cardiac output were observed in nonsurviving patients. Conclusion: There was a persistently high systemic vascular resistance index in cold shock patients that influenced the stroke volume index, cardiac index, and velocity time integral. The use of echocardiograms for hemodynamic measurements is important in pediatric septic shock patients to adjust dilators, and vasopressor doses and achieve resuscitation targets in a timely manner.

Comparison of Cardiac and Vascular Parameters in Powerlifters and Long-Distance Runners: Comparative Cross-Sectional Study / Comparação de Parâmetros Cardíacos e Vasculares em Powerlifters e Corredores de Longa Distância: Um Estudo Transversal Comparativo

Abstract Background: Cardiac remodeling is a specific response to exercise training and time exposure. We hypothesized that athletes engaging for long periods in high-intensity strength training show heart and/or vascular damage. Objective: To compare cardiac characteristics (structure and function) and vascular function (flow-mediated dilation [FMD] and peripheral vascular resistance [PVR]) in powerlifters and long-distance runners. Methods: We evaluated 40 high-performance athletes (powerlifters [PG], n = 16; runners [RG], n = 24) and assessed heart structure and function (echocardiography), systolic and diastolic blood pressure (SBP/DBP), FMD, PVR, maximum force (squat, bench press, and deadlift), and maximal oxygen uptake (spirometry). A Student's t Test for independent samples and Pearson's linear correlation were used (p < 0.05). Results: PG showed higher SBP/DBP (p < 0.001); greater interventricular septum thickness (p < 0.001), posterior wall thickness (p < 0.001) and LV mass (p < 0.001). After adjusting LV mass by body surface area (BSA), no difference was observed. As for diastolic function, LV diastolic volume, wave E, wave e', and E/e' ratio were similar for both groups. However, LA volume (p = 0.016) and BSA-adjusted LA volume were lower in PG (p < 0.001). Systolic function (end-systolic volume and ejection fraction), and FMD were similar in both groups. However, higher PVR in PG was observed (p = 0.014). We found a correlation between the main cardiovascular changes and total weight lifted in PG. Conclusions: Cardiovascular adaptations are dependent on training modality and the borderline structural cardiac changes are not accompanied by impaired function in powerlifters. However, a mild increase in blood pressure seems to be related to PVR rather than endothelial function.

Resumo Fundamento: Remodelamento cardíaco é uma resposta específica ao tempo e modalidade de treinamento. Nós hipotetizamos que atletas de treinamento de força de alta intensidade, por longo tempo, mostram dano à estrutura cardíaca e/ou vascular. Objetivo: Comparar as características cardíacas (estrutura e funcionalidade) e função vascular (dilatação fluxo-mediada, FMD e resistência vascular periférica, PVR) em powerlifters e corredores. Métodos: Nós avaliamos 40 atletas de alto-desempenho (powerlifters [PG], n = 16; corredores [RG], n = 24). Mensuramos estrutura e funcionalidade cardíaca (ecocardiografia), pressão arterial (SBP/DBP), FMD, PVR, força máxima (agachamento, supino e levantamento terra) e consumo máximo de oxigênio (ergoespirometria). Foi utilizado teste T de Student e correlação linear de Pearson (p < 0,05). Resultados: PG mostrou maior SBP/DBP (p < 0,001), espessura de septo interventricular (p < 0,001), parede posterior (p < 0,001) e massa do VE (p < 0,001); após ajuste pela superfície corporal (BSA), não houve diferença na massa do VE. O volume do VE, onda E, onda e', e a razão E/e' foram similares entre os grupos. O volume do AE (p = 0,016), mesmo ajustado pela BSA (p < 0,001) foi menor no PG. A função sistólica (volume sistólico final e fração de ejeção) e FMD foram similares nos grupos. Contudo, foi observada maior PVR no PG (p = 0,014). Houve uma correlação direta entre as alterações cardíacas e a carga total levantada no PG. Conclusões: As adaptações cardiovasculares são dependentes da modalidade e os valores encontrados na estrutura do coração não são acompanhados por prejuízo na funcionalidade. Entretanto, um leve aumento na pressão arterial pode estar associado com maior PVR e não com a função endotelial.

Lidocaine and pinacidil added to blood versus crystalloid cardioplegic solutions: study in isolated hearts

Abstract Objective: The present study aimed the functional recovery evaluation after long term of cardiac arrest induced by Custodiol (crystalloid-based) versus del Nido (blood-based) solutions, both added lidocaine and pinacidil as cardioplegic agents. Experiments were performed in isolated rat heart perfusion models. Methods: Male rat heart perfusions, according to Langendorff technique, were induced to cause 3 hours of cardiac arrest with a single dose. The hearts were assigned to one of the following three groups: (I) control; (II) Custodiol-LP; and (III) del Nido-LP. They were evaluated after ischemia throughout 90 minutes of reperfusion. Left ventricular contractility function was reported as percentage of recovery, expressed by developed pressure, maximum dP/dt, minimum dP/dt, and rate pressure product variables. In addition, coronary resistance and myocardial injury marker by alpha-fodrin degradation were also evaluated. Results: At 90 minutes of reperfusion, both solutions had superior left ventricular contractile recovery function than the control group. Del Nido-LP was superior to Custodiol-LP in maximum dP/dt (46%±8 vs. 67%±7, P<0.05) and minimum dP/dt (31%±4 vs. 51%±9, P<0.05) variables. Coronary resistance was lower in del Nido-LP group than in Custodiol-LP (395%±50 vs. 307%±13, P<0.05), as well as alpha-fodrin degradation, with lower levels in del Nido-LP group (P<0.05). Conclusion: Del Nido-LP cardioplegia showed higher functional recovery after 3 hours of ischemia. The analysis of alpha-fodrin degradation showed del Nido-LP solution provided greater protection against myocardial ischemia and reperfusion (IR) in this experimental model.

Exercise Training Attenuates Sympathetic Activity and Improves Morphometry of Splenic Arterioles in Spontaneously Hipertensive Rats / Treinamento Físico Atenua a Atividade Simpática e Melhora a Morfometria das Arteríolas Esplênicas em Ratos Espontaneamente Hipertensos

Abstract Background: Alterations in the structure of resistance vessels contribute to elevated systemic vascular resistance in hypertension and are linked to sympathetic hyperactivity and related lesions in target organs. Objective: To assess the effects of exercise training on hemodynamic and autonomic parameters, as well as splenic arteriolar damages in male Wistar Kyoto (WKY) and Spontaneously Hypertensive Rats (SHR). Methods: Normotensive sedentary (WKYS) and trained (WKYT) rats, and hypertensive sedentary (SHRS) and trained (SHRT) rats were included in this study. After 9 weeks of experimental protocol (swimming training or sedentary control), arterial pressure (AP) and heart rate (HR) were recorded in freely moving rats. We assessed the autonomic control of the heart by sympathetic and vagal autonomic blockade. Morphometric analyses of arterioles were performed in spleen tissues. The statistical significance level was set at p < 0.05. Results: Resting bradycardia was observed in both trained groups (WKYT: 328.0 ± 7.3 bpm; SHRT: 337.0 ± 5.2 bpm) compared with their respective sedentary groups (WKYS: 353.2 ± 8.5 bpm; SHRS: 412.1 ± 10.4 bpm; p < 0.001). Exercise training attenuated mean AP only in SHRT (125.9 ± 6.2 mmHg) vs. SHRS (182.5 ± 4.2 mmHg, p < 0.001). The WKYT showed a higher vagal effect (∆HR: 79.0 ± 2.3 bpm) compared with WKYS (∆HR: 67.4 ± 1.7 bpm; p < 0.05). Chronic exercise decreased sympathetic effects on SHRT (∆HR: -62.8 ± 2.8 bpm) in comparison with SHRS (∆HR: -99.8 ± 9.2 bpm; p = 0.005). The wall thickness of splenic arterioles in SHR was reduced by training (332.1 ± 16.0 µm2 in SHRT vs. 502.7 ± 36.3 µm2 in SHRS; p < 0.05). Conclusions: Exercise training attenuates sympathetic activity and AP in SHR, which may be contributing to the morphological improvement of the splenic arterioles.

Resumo Fundamento: Alterações na estrutura dos vasos de resistência contribuem para elevar a resistência vascular sistêmica na hipertensão, estando ligadas à hiperatividade simpática e lesões em órgãos-alvo. Objetivo: Avaliar os efeitos do treinamento físico nos parâmetros hemodinâmicos e autônomos, assim como as lesões arteriolares esplênica em ratos machos Wistar Kyoto (WKY) e espontaneamente hipertensos (SHR). Métodos: Ratos normotensos sedentários (WKYS) e treinados (WKYT), e ratos hipertensos sedentários (SHRS) e treinados (SHRT) foram incluídos neste estudo. Após nove semanas de aplicação do protocolo experimental (treinamento de natação ou controle sedentário), registraram-se a pressão arterial (PA) e a frequência cardíaca (FC) dos ratos em movimento livre. Avaliamos o controle autônomo do coração através de bloqueio autônomo simpático e vagal. Análises morfométricas das arteríolas esplênicas foram realizadas. Adotou-se o nível de significado estatístico de p < 0,05. Resultados: Observou-se bradicardia de repouso nos dois grupos treinados (WKYT: 328,0 ± 7,3 bpm; SHRT: 337,0 ± 5,2 bpm) em comparação aos seus respectivos grupos sedentários (WKYS: 353,2 ± 8,5 bpm; SHRS: 412,1 ± 10,4 bpm; p < 0,001). O treinamento físico atenuou a PA média apenas no grupo SHRT (125,9 ± 6,2 mmHg vs. 182,5 ± 4,2 mmHg no SHRS; p < 0,001). O grupo WKYT mostrou maior efeito vagal (∆FC: 79,0 ± 2,3 bpm) em comparação ao grupo WKYS (∆FC: 67,4 ± 1,7 bpm; p < 0,05). Exercício crônico diminuiu os efeitos simpáticos em SHRT (∆FC: -62.8 ± 2.8 bpm) em comparação a SHRS (∆FC: -99,8 ± 9,2 bpm; p = 0,005). A espessura da parede das arteríolas esplênicas nos SHR foi reduzida pelo treinamento (332,1 ± 16,0 µm2 nos SHRT vs. 502,7 ± 36,3 µm2 nos SHRS; p < 0,05). Conclusões: O treinamento físico atenua a atividade simpática e a PA em SHR, o que pode contribuir para melhorar a morfologia das arteríolas esplênicas.

Autonomic and Vascular Control in Prehypertensive Subjects with a Family History of Arterial Hypertension / Controle Autonômico e Vascular em Pré-Hipertensos com Histórico Familiar de Hipertensão Arterial

Abstract Background: Individuals with a family history of systemic arterial hypertension (FHSAH) and / or prehypertension have a higher risk of developing this pathology. Objective: To evaluate the autonomic and vascular functions of prehypertensive patients with FHSAH. Methods: Twenty-five young volunteers with FHSAH, 14 normotensive and 11 prehypertensive subjects were submitted to vascular function evaluation by forearm vascular conductance(VC) during resting and reactive hyperemia (Hokanson®) and cardiac and peripheral autonomic modulation, quantified, respectively, by spectral analysis of heart rate (ECG) and systolic blood pressure (SBP) (FinometerPRO®). The transfer function analysis was used to measure the gain and response time of baroreflex. The statistical significance adopted was p ≤ 0.05. Results: Pre-hypertensive individuals, in relation to normotensive individuals, have higher VC both at rest (3.48 ± 1.26 vs. 2.67 ± 0.72 units, p = 0.05) and peak reactive hyperemia (25, 02 ± 8.18 vs. 18.66 ± 6.07 units, p = 0.04). The indices of cardiac autonomic modulation were similar between the groups. However, in the peripheral autonomic modulation, greater variability was observed in prehypertensive patients compared to normotensive individuals (9.4 [4.9-12.7] vs. 18.3 [14.8-26.7] mmHg2; p < 0.01) and higher spectral components of very low (6.9 [2.0-11.1] vs. 13.5 [10.7-22.4] mmHg2, p = 0.01) and low frequencies (1.7 [1.0-3.0] vs. 3.0 [2.0-4.0] mmHg2, p = 0.04) of SBP. Additionally, we observed a lower gain of baroreflex control in prehypertensive patients compared to normotensive patients (12.16 ± 4.18 vs. 18.23 ± 7.11 ms/mmHg, p = 0.03), but similar delay time (-1.55 ± 0.66 vs. -1.58 ± 0.72 s, p = 0.90). Conclusion: Prehypertensive patients with FHSAH have autonomic dysfunction and increased vascular conductance when compared to normotensive patients with the same risk factor.

Resumo Fundamento: Indivíduos com histórico familiar de hipertensão arterial sistêmica (HFHAS) e/ou pré-hipertensão apresentam maior risco de desenvolver essa patologia. Objetivo: Avaliar as funções autonômica e vascular de pré-hipertensos com HFHAS. Métodos: Vinte e cinco voluntários jovens com HFHAS, sendo 14 normotensos e 11 pré-hipertensos foram submetidos à avaliação da função vascular, por meio da condutância vascular do antebraço (CV) durante repouso e hiperemia reativa (Hokanson®), e da modulação autonômica cardíaca e periférica, quantificada, respectivamente, por meio da análise espectral da frequência cardíaca (ECG) e da pressão arterial sistólica (PAS) (FinometerPRO®). A análise da função de transferência foi utilizada para mensurar o ganho e o tempo de resposta do barorreflexo. A significância estatística adotada foi p ≤ 0,05. Resultados: Pré-hipertensos, em relação aos normotensos, tem maior CV tanto em repouso (3,48 ± 1,26 vs. 2,67 ± 0,72 unidades; p = 0,05) quanto no pico hiperemia reativa (25,02 ± 8,18 vs. 18,66 ± 6,07 unidades; p = 0,04). Os índices da modulação autonômica cardíaca foram semelhantes entre os grupos. Entretanto, na modulação autonômica periférica, foi observado, nos pré-hipertensos em relação aos normotensos, maior variabilidade (9,4 [4,9-12,7] vs. 18,3 [14,8-26,7] mmHg2; p < 0,01) e maiores componentes espectrais de muito baixa (6,9 [2,0-11,1] vs. 13,5 [10,7-22,4] mmHg2; p = 0,01) e baixa frequências (1,7 [1,0-3,0] vs. 3,0 [2,0-4,0] mmHg2; p = 0,04) da PAS. Adicionalmente, observamos menor ganho do controle barorreflexo nos pré-hipertensos em relação aos normotensos (12,16 ± 4,18 vs. 18,23 ± 7,11 ms/mmHg; p = 0,03), porém, tempo de retardo semelhante (-1,55 ± 0,66 vs. -1,58 ± 0.72 s; p = 0,90). Conclusão: Pré-hipertensos com HFHAS tem disfunção autonômica e condutância vascular aumentada quando comparados a normotensos com o mesmo fator de risco.

Mecanismos regulatorios del tono vascular pulmonar neonatal: una perspectiva molecular / Regulatory mechanisms of neonatal pulmonary vascular tone: a molecular perspective

La adaptación al medio extrauterino incluye un aumento considerable de la PaO2, que induce especialmente cambios estructurales y vasoactivos en la circulación pulmonar, que llevarán a una circulación previamente pobremente irrigada, a recibir ∼100% del gasto cardíaco del recién nacido, permitiendo el normal intercambio gaseoso. La regulación local de la circulación arterial pulmonar neonatal basal, es mantenida por un delicado equilibrio entre agentes vasoconstrictores y vasodilatadores. Este equilibrio, permite mantener la circulación pulmonar como un territorio de gran flujo sanguíneo y baja resistencia. La acción de los vasoconstrictores permite la formación de las interacciones entre actina y la cadena liviana de la miosina, esta es inducida en la célula muscular lisa principalmente por dos vías: a) dependiente de calcio, que consiste en aumentar el calcio intracelular, facilitando finalmente la unión de actina y miosina, y b) independiente de calcio, la cual a través de consecutivas fosforilaciones logra sensibilizar a las proteínas involucradas promoviendo la unión de actina y miosina. Estas acciones son mediadas por agonistas generados principalmente en el endotelio pulmonar, como endotelina-1 y tromboxano, o por agonistas provenientes de otros tipos celulares como la serotonina. Los agentes vasodilatadores regulan la respuesta vasoconstrictora, principalmente inhibiendo la señalización que induce la vasocontricción independiente de calcio, a través de la activación de proteínas quinasas que inhibirán la función de la ROCK quinasa, uno de los últimos efectores de la vasocontricción antes de la formación de la unión de actina y miosina. Esta revisión describe estos mecanismos de primordial importancia en las primeras horas de nuestra vida como individuos independientes.

The extrauterine-milieu adaptation includes a considerable increase in PaO2, that specifically induces structural and vasoactive changes at pulmonary circulation. Such changes transform a poor irrigated circulation into a circulation that receive ∼100% of neonatal cardiac output, supporting the normal alveolar-capillary gas exchange. Local regulation of basal neonatal pulmonary circulation is maintaining by a delicate equilibrium between vasoconstrictor and vasodilator agents. This equilibrium, allows to maintain the pulmonary circulation as an hemodynamic system with a high blood flow and a low vascular resistance. Vasocontrictors action allows actin and light-chain myosin interaction. Two main pathways induced this effect in smooth muscle cell: a) a calcium dependent pathway, that increases intracellular calcium, facilitating actin - myosin binding, and b) the independent calcium pathway, which achieves through consecutive phosphorylation reactions sensitize the proteins involved, promoting the binding of actin and light-chain myosin. These actions are mediated by agonists produced mainly in the pulmonary endothelium, such as endothelin-1 and thromboxane, or by agonists from other cell types such as serotonin. Vasodilator agents regulate the vasoconstrictor response, mainly by inhibiting signals that induce calcium-independent vasoconstriction, through activation of protein kinases, which in turn will inhibit the function of ROCK kinase, one of the last effectors of vasoconstriction before formation of the actin and light-chain myosin binding. This review will focus on describing these mechanisms of primal importance in the first hours of our lives as independent individuals.

Association of Inflammation and Endothelial Dysfunction with Coronary Microvascular Resistance in Patients with Cardiac Syndrome X / Associação de Inflamação e Disfunção Endotelial com Resistência Microvascular Coronariana em Pacientes com Síndrome Cardíaca X

Abstract Background: Although a proportion of CSX patients have impaired brachial artery flow-mediated dilatation (FMD) in response to hyperemia, suggesting that endothelial dysfunction in these patients may be systemic and not just confined to the coronary circulation; the underlying mechanisms triggering endothelial dysfunction in these patients are still incompletely understood. Objectives: To assess the association of the index of Microcirculatory Resistance (IMR) with endothelial dysfunction and inflammation in patients with CSX. Methods: We studied 20 CSX patients and 20 age and gender-matched control subjects. Thermodilution-derived coronary flow reserve (CFR) and IMR were measured using a pressure-temperature sensor-tipped guidewire. Brachial artery FMD was measured using high-resolution, two-dimensional ultrasound images obtained with a Doppler ultrasound device (HDI-ATL 5000, USA) with a 5 MHz to 12 MHz linear-array transducer. Results: Compared with in control subjects, CFR was significantly lower (2.42 ± 0.78 vs. 3.59 ± 0.79, p < 0.001); IMR was higher (32.2 ± 8.0 vs. 19.5 ± 5.5, p < 0.001); the concentration of hs-CRP and FMD was higher (4.75 ± 1.62 vs. 2.75 ± 1.50; 5.24 ± 2.41 vs. 8.57 ± 2.46, p < 0.001) in CSX patients. The Duke treadmill score (DTS) was correlated positively to CFR and FMD (0.489 and 0.661, p < 0.001), it was negative to IMR and hsCRP (-0.761 and -0.087, p < 0.001) in CSX patients. Conclusions: The main finding in this study is that the DTS measured in patients with CSX was associated to hsCRP and FMD. Moreover, the independent effects of exercise tolerance can significantly impair FMD and hsCRP in CSX patients; especially it is particularly important to whom where FMD was associated negatively with IMR.

Resumo Fundamentos: Embora uma proporção de pacientes com SCX tenha dilatação mediada por fluxo da artéria braquial (DMF) prejudicada em resposta à hiperemia, sugerindo que a disfunção endotelial nestes pacientes pode ser sistémica e não limitar-se à circulação coronariana, os mecanismos subjacentes que desencadeiam a disfunção endotelial nestes pacientes ainda não são completamente compreendidos. Objetivos: Avaliar a associação do índice de resistência microcirculatória (IMR) com a disfunção endotelial e a inflamação em pacientes com SCX. Métodos: Estudaram-se 20 pacientes com SCX e 20 sujeitos de controle emparelhados em idade e género. A reserva de fluxo coronariano derivada da termodiluição (RFC) e a IMR forma medidas usando um fio guia com ponta de sensor de temperatura e pressão. A DMF da artéria braquial foi medida utilizando imagens ultrassónicas bidimensionais de alta resolução obtidas com um aparelho de ultrassom Doppler (HDI-ATL 5000, EE.UU.) com transdutor linear de 5 MHz a 12 MHz. Resultados: Em comparação com os sujeitos de controle, a RFC foi significativamente menor (2,42 ± 0,78 vs 3,59 ± 0,79, p < 0,001); o IMR foi maior (32,2 ± 8,0 frente a 19,5 ± 5,5, p < 0,001); a concentração de PCR-as e DMF foi maior (4,75 ± 1,62 frente a 2,75 ± 1,50, 5,24 ± 2,41 diante de 8,57 ± 2,46, p < 0,001) em pacientes com SCX. A escore de Duke (ED) se correlacionou positivamente com RFC e DMF (0,489 e 0,661, p < 0,001), foi negativa para IMR e PCR-as (-0,761 e -0,087, p < 0,001) em pacientes com SCX. Conclusões: O principal achado neste estudo é que o ED medido em pacientes com SCX esteve associado a PCR-as e DMF. Por outra parte, os efeitos independentes da tolerância ao exercício podem piorar significativamente a DMF e a PCR-as em pacientes com SCX especialmente, é particularmente importante que a DMF se associou negativamente com a RIM.

Antiretroviral therapy and arterial elasticity in HIV-infected patients

Cardiovascular risk is increased in HIV-infected patients and has become a leading cause of morbimortality in this population. The purpose of this study is to compare HIV-infected patients on antiretroviral therapy (ART) and ART-naïve HIV-infected patients regarding arterial elasticity. From September 2010 to September 2015, 105 HIV-infected subjects were enrolled, 41 ART-naïve and 64 on ART with stable viral suppression. Elasticity of large and small arteries (LAE and SAE) was assessed by analysis of radial pulse waveforms using a calibrated device. A single set of measurements was performed. Multivariate linear regression models were constructed to estimate independent correlates of arterial elasticity. On-ART and ART-naïve patients were similar with respect to gender, age, body mass index, Framingham cardiovascular risk score, smoking habits, and CD4+ counts. Median time on treatment was 60 months and 79% of patients were on regimens based on non-nucleoside reverse-transcriptase inhibitors. No significant differences in LAE and SAE assessments were found between groups. However, time on ART and cholesterol levels were independently associated with LAE impairment. No association between arterial elasticity and CD4+ counts was found. We conclude that cumulative exposure to ART may play a role on LAE impairment and deserves further investigation.

El riesgo cardiovascular está incrementado en los pacientes HIV seropositivos y se ha convertido en una de las principales causas de morbimortalidad en esta población. El objetivo de este estudio fue comparar la elasticidad de grandes y pequeñas arterias (LAE y SAE) en pacientes infectados por HIV con y sin terapia antirretroviral. De septiembre de 2010 a septiembre de 2015 se enrolaron 105 pacientes con infección por HIV, 41 vírgenes de antirretrovirales y 64 con tratamiento estable en supresión viral. LAE y SAE fueron evaluados mediante análisis de la onda de pulso radial. Se construyeron modelos de regresión lineal múltiple para evaluar los predictores independientes de la elasticidad arterial. Los grupos en tratamiento y naïve fueron similares con respecto al sexo, edad, índice de masa corporal, índice de Framingham, tabaquismo y recuento de CD4+. La mediana de tiempo en tratamiento antirretroviral fue 60 meses y el 79% de los pacientes recibieron inhibidores no nucleosídicos. No hubo diferencias significativas entre los grupos en los valores de LAE y SAE. Sin embargo, el tiempo en tratamiento y el nivel de colesterol plasmático se asociaron independientemente con deterioro de LAE. No observamos asociaciones entre la elasticidad arterial y los recuentos de CD4+. Concluimos que la exposición acumulada al tratamiento antirretroviral podría contribuir al deterioro de la LAE. Este hallazgo merece ulterior investigación.

Prueba de vasorreactividad con iloprost en hipertensión arterial pulmonar / Proof of vasoreactivity with iloprost in pulmonary arterial hypertension

Resumen Introducción: la detección de vasorreactividad pulmonar en hipertensión pulmonar es importante para determinar el beneficio del tratamiento con calcioantagonistas a largo plazo. En los últimos años se ha utilizado el iloprost como alternativa para la realización de la prueba con buenos resultados, por lo que es importante evaluar su respuesta en pacientes con esta enfermedad. Métodos: estudio cuasiexperimental no controlado con diseño de antes y después para evaluar la respuesta a un vasodilatador inhalado en pacientes remitidos al laboratorio de hemodinamia para pruebas de reactividad pulmonar. Se analizó una muestra no probabilística por conveniencia con la cohorte descrita. Se les realizó cateterismo derecho con medición de parámetros hemodinámicos y se evaluó la respuesta a la administración de 10 mcg de iloprost inhalado. Se consideró positiva la prueba si la presión arterial pulmonar media disminuía > 10 mmHg hasta < 40 mmHg, con aumento del gasto cardiaco o sin cambios en éste. Resultados: se incluyeron 30 pacientes; el promedio de edad fue de 55.5 ± 12 años, el 76.7% fueron mujeres y la fracción de eyección del ventrículo izquierdo fue de 52 ± 10%. La prueba se consideró positiva en 16.7% de los casos, sin complicaciones relacionadas al uso del medicamento. Se observó aumento no significativo del gasto cardiaco, con descenso importante en la resistencia vascular sistémica (1279 ± 438 vs 1110± 379, p=0.000004), resistencia vascular pulmonar (483 ± 210 vs 383 ± 185, p=0.000002), presión arterial pulmonar (47 ± 6 vs 39 ± 7, p=0.000002) y presión en cuña de la arteria pulmonar (16 ± 5 vs 15 ± 4, p<0.00009). Conclusión: el uso de iloprost inhalado en dosis de 10 mcg, en pacientes con hipertensión pulmonar llevados a cateterismo cardiaco derecho es una alternativa para identificar vasorreactividad, con baja tasa de eventos adversos. (Acta Med Colomb 2016; 40: 229-234).

Abstract Introduction: the detection of pulmonary vasoreactivity in pulmonary hypertension is important to determine the benefit of treatment with long-term calcium antagonists. In recent years, iloprost has been used as an alternative to perform the test with good results, so it is important to evaluate its response in patients with this disease. Methods: a quasi-experimental, uncontrolled study with before and after design to evaluate the response to an inhaled vasodilator in patients referred to the hemodynamic laboratory for pulmonary reactivity tests. A non-probabilistic sample was analyzed for convenience with the described cohort. Right catheterization was performed with measurements of hemodynamic parameters and the response to administration of 10 mcg of inhaled iloprost was performed in these patients. The test was considered positive if mean pulmonary artery pressure decreased >10 mmHg to <40 mmHg, with or without cardiac output increase. Results: 30 patients were included; mean age was 55.5 ± 12 years, 76.7% were women and the left ventricular ejection fraction was 52 ± 10%. The test was considered positive in 16.7% of cases, without complications related to the use of the drug. There was significant increase in cardiac output with an important decrease in systemic vascular resistance (1279 ± 438 vs 1110 ± 379, p = 0.000004), pulmonary vascular resistance (483 ± 210 vs 383 ± 185, p = 0.000002), blood pressure (47 ± 6 vs 39 ± 7, p = 0.000002), and wedge pressure of the pulmonary artery (16 ± 5 vs. 15 ± 4, p <0.00009). Conclusion: The use of inhaled iloprost in doses of 10 mcg in patients with pulmonary hypertension taken to right cardiac catheterization is an alternative to identify vasoreactivity with low rate of adverse events. (Acta Med Colomb 2016; 40: 229-234).

Intraoperative analysis of flow dynamics in arteriovenous composite y grafts

Abstract Objective: Composite graft of left internal thoracic artery and great saphenous vein in revascularization of the left coronary system is a technique well described in literature. The aim of this study is to analyze blood flow dynamics in this configuration of composite graft especially in what concerns left internal thoracic artery's adaptability and influence of great saphenous vein segment on left internal thoracic artery's flow. Methods: Revascularization of left coronary system with composite graft, with left internal thoracic artery revascularizing the anterior interventricular artery and a great saphenous vein segment, anastomosed to the left internal thoracic artery, revascularizing another branch of the left coronary system, was performed in 23 patients. Blood flow was evaluated by transit time flowmetry in all segments of the composite graft (left internal thoracic artery proximal segment, left internal thoracic artery distal segment and great saphenous vein segment). Measures were performed in baseline condition and after dobutamine-induced stress, without and with non-traumatic temporary clamping of the distal segments of the composite graft. Results: Pharmacological stress resulted in increase of blood flow values in the analyzed segments (P<0.05). Non-traumatic temporary clamping of great saphenous vein segment did not result in statistically significant changes in the flow of left internal thoracic artery distal segment, both in baseline condition and under pharmacological stress. Similarly, non-traumatic temporary clamping of left internal thoracic artery distal segment did not result in statistically significant changes in great saphenous vein segment flow. Conclusion: Composite grafts with left internal thoracic artery and great saphenous vein for revascularization of left coronary system, resulted in blood flow dynamics with physiological adaptability, both at rest and after pharmacological stress, according to demand. Presence of great saphenous vein segment did not alter physiological blood flow dynamics in distal segment of left internal thoracic artery.

Prognostic Value of Pulmonary Vascular Resistance by Magnetic Resonance in Systolic Heart Failure / Valor Prognóstico da Resistência Vascular Pulmonar através de Ressonância Magnética em Insuficiência Cardíaca

Abstract Background: Pulmonary hypertension is associated with poor prognosis in heart failure. However, non-invasive diagnosis is still challenging in clinical practice. Objective: We sought to assess the prognostic utility of non-invasive estimation of pulmonary vascular resistances (PVR) by cardiovascular magnetic resonance to predict adverse cardiovascular outcomes in heart failure with reduced ejection fraction (HFrEF). Methods: Prospective registry of patients with left ventricular ejection fraction (LVEF) < 40% and recently admitted for decompensated heart failure during three years. PVRwere calculated based on right ventricular ejection fraction and average velocity of the pulmonary artery estimated during cardiac magnetic resonance. Readmission for heart failure and all-cause mortality were considered as adverse events at follow-up. Results: 105 patients (average LVEF 26.0 ±7.7%, ischemic etiology 43%) were included. Patients with adverse events at long-term follow-up had higher values of PVR (6.93 ± 1.9 vs. 4.6 ± 1.7estimated Wood Units (eWu), p < 0.001). In multivariate Cox regression analysis, PVR ≥ 5 eWu(cutoff value according to ROC curve) was independently associated with increased risk of adverse events at 9 months follow-up (HR2.98; 95% CI 1.12-7.88; p < 0.03). Conclusions: In patients with HFrEF, the presence of PVR ≥ 5.0 Wu is associated with significantly worse clinical outcome at follow-up. Non-invasive estimation of PVR by cardiac magnetic resonance might be useful for risk stratification in HFrEF, irrespective of etiology, presence of late gadolinium enhancement or LVEF.

Resumo Fundamento: A hipertensão pulmonar está associada a mau prognóstico em insuficiência cardíaca. No entanto, o diagnóstico não-invasivo é desafiador na prática clínica. Objetivo: Avaliar a utilidade prognóstica da estimativa não-invasiva das resistências vasculares pulmonares (RVP) medidas através de ressonância magnética cardiovascular na previsão de desfechos cardiovasculares adversos em insuficiência cardíaca com fração de ejeção reduzida (ICFEr). Métodos: Registro prospectivo de pacientes com fração de ejeção do ventrículo esquerdo (FEVE) < 40% internados recentemente por insuficiência cardíaca descompensada, durante três anos. As RVP foram calculadas com base na fração de ejeção do ventrículo esquerdo e velocidade média do fluxo na artéria pulmonar estimada por ressonância magnética cardíaca. Durante a evolução, reinternação por insuficiência cardíaca e mortalidade por todas as causas foram consideradas eventos adversos. Resultados: Foram incluídos 105 pacientes (FEVE média de 26,0 ± 7,7%, etiologia isquêmica em 43%). Os valores de RVP nos pacientes que apresentaram eventos adversos durante o seguimento em longo prazo foram mais altos (6,93 ± 1,9 versus 4,6 ± 1,7 unidades Wood estimadas (uWe), p < 0,001). Na análise de regressão multivariada de Cox, RVP ≥ 5 eWu (valor de corte segundo a curva ROC) mostrou-se independentemente associada a um maior risco de eventos adversos aos 9 meses de seguimento (RR = 2,98; IC 95% = 1,12-7,88; p < 0,03). Conclusões: Em pacientes com ICFEr, a presença de RVP ≥ 5,0 uW está associada a uma evolução clínica significativamente pior. A estimativa não-invasiva da RVP através de ressonância magnética cardíaca pode ser útil na estratificação de risco em ICFEr, independentemente da etiologia, presença de realce tardio pelo gadolínio ou FEVE.