Uso de treprostinil sistémico en una paciente con hipertensión pulmonar grave, sin respuesta a la máxima terapia disponible / Use of treprostinil in a patient with a severe pulmonary arterial hypertension no responding to the maximal therapy available

En los pacientes con Hipertensión Arterial Pulmonar (HAP) de alto riesgo, en clase funcional (CF)IV, la terapia específica debe ser combinada y debe incluir una prostaciclina (PGI2) de uso sistémico en espera de trasplante bipulmonar (TBP). En el sistema público la única PGI2 disponible para asociar a Sildenafil y algún inhibidor de endotelina (Ambrisentan o Bosentan) es Iloprost nebulizado, que si bien es efectiva, no logra estabilizar los casos graves con severa disfunción del ventrículo derecho (VD). Se presenta el primer caso en el Instituto del Tórax, centro de referencia nacional de HAP, del uso de treprostinil en una paciente de 24 años con HAP grave e indicación de TBP. Treprostinil es un análogo sintético de PGI2 de uso subcutáneo en dosis desde 1 a 40 ng/kg/min. La paciente presentaba una situación de extrema gravedad: CF IV, distancia recorrida en el test de caminata de 6 min (DRTC 6 min) < 300 m,derrame pericárdico y severa disfunción del VD con TAPSE (índice de disfunción del VD) de 13 cm/s asociado a ProBNP >2.500 pg/ml. Luego de 6 meses de hospitalización en intermedio, terapia triple (Sildenafil, Ambrisentan e Iloprost nebulizado) asociado a O2,diuréticos y milrinona, logró ser dada de alta a las 3 semanas del inicio de treprostinil, regresando al trabajo a los 2 meses y estabilizando su condición en CF III, con DRTC 6 min > 440 m, mejoría de la función del VD(TAPSE 19). El ProBNP persistió elevado, 1.491 pg/ml, indicando que su enfermedad es grave y progresiva; sin embargo, ha logrado un nivel de estabilidad clínica que le permite una adecuada vida de relación familiar y laboral.

In high risk Pulmonary Arterial Hypertension (PAH) patients with functional class (FC) IV, specific therapy must be combined and must include systemic prostacyclin (PGI2), meanwhile they are enlisted for double lung transplant (DLT). In Chilean Public Health System, nebulized Iloprost is the only PGI2 available to combine with Sildenafil and either Ambrisentan or Bosentan as endothelin receptor antagonist. This association is not enough for severe cases with right ventricular (RV) dysfunction. The first case from the National Institute of Thorax as a referral center is presented now in a 24 years-old lady treated with treprostinil. She has severe PAH with DLT indication. Treprostinil is a PGI2 analog, for subcutaneous use in a dose from 1 to 40 ng/kg/min. She was extremely sick, with FC IV, she walked < 300 m at 6 min walking test (6 MWT), presented pericardial effusion and severe RV dysfunction, with TAPSE (echocardiography index for RV dysfunction)=13 cm/s, ProBNP > 2,500 pg/ml. Six months after being at intensive care unit with triple therapy (Sildenafil, ambrisentan and nebulized Iloprost) plus oxygen, diuretics and milrinone, she was finally discharged after receiving a 3 weeks treprostinil course. She came back to work two months later and her condition was more stable: FC III, she walked > 440 m at 6MWT, with a significant improvement in RV function with TAPSE = 19. Although ProBNP decreased to 1,491pg/ml, it was still high, pointing out the progressive nature of her disease. However, she met a better clinical condition which allows her to reach a much better quality of life from a personal, familial and social point of view.

Análogos de prostaglandinas I2 (epoprostenol y treprostinil) para el tratamiento de la hipertensión pulmonar refractaria secundaria a displasia broncopulmonar en un lactante / Prostaglandin 12 analogs (epoprostenol and treprostinil) as a treatment for refractory bronchopulmonary dysplasia-induced pulmonary hypertension in an infant

La hipertensión pulmonar es una complicación frecuente de la displasia broncopulmonar. A pesar de su alta incidencia, existen pocos tratamientos disponibles. El epoprostenol y el treprostinil son análogos de las prostaglandinas I2, que activan la adenilato ciclasa e incrementan el adenosín monofosfato cíclico en las células de la musculatura lisa de la arteria pulmonar y pueden resultar eficaces en el tratamiento de estos pacientes. Se presenta el caso de un prematuro de extremado bajo peso con hipertensión pulmonar secundaria a displasia broncopulmonar grave, no respondedora a óxido nítrico inhalado y sildenafilo, que fue tratado con análogos de prostaglandinas I2. En nuestro paciente, este tratamiento evidenció mejoría clínica y ecocardiográfica significativa tras varias semanas de tratamiento.

Pulmonary hypertension is a common complication of bronchopulmonary dysplasia, with a high mortality rate. Despite the high incidence of pulmonary hypertension, there are few available treatments. Epoprostenol and treprostinil are prostaglandin I2 analogs that activate adenylate cyclase and increase cyclic adenosine monophosphate in the pulmonary arterial smooth muscle cells. Therefore, they may be an effective treatment for these patients. We report the use of prostaglandin I2 analogs in an extremely low birth weight preterm baby with severe bronchopulmonary dysplasia associated with pulmonary hypertension non-responding to inhaled nitric oxide and sildenafil. In our patient this treatment resulted in remarkable clinical and echocardiographic improvement, evident after a few weeks of treatment.

Protective effects of baicalin on experimental myocardial infarction in rats

Abstract Objective: This study aimed to investigate the protective effects of baicalin on myocardial infarction in rats and explore the related mechanisms. Methods: Fifty Sprague Dawley rats were randomly divided into the control, model, and low-, medium- and high-dose baicalin groups. The latter 3 groups were intraperitoneally injected with baicalin, with a dose of 12.5, 25 and 50 mg/kg, respectively. Then, the myocardial infarction model was established. The hemodynamic of rats was tested, the serum lactate dehydrogenase (LDH), creatine kinase-MB (CK-MB), prostacyclin (PGI2) and thromboxane A2 (TXA2) were determined, the myocardial superoxide dismutase (SOD) and malondialdehyde (MDA) levels were detected, and the myocardial B-cell lymphoma-2 (Bcl-2) and Bcl-2 associated X (Bax) protein expressions were determined. Results: Compared with the model group, in the high-dose baicalin group the ST segment height and LVEDP were significantly decreased (P<0.05), the LVSP was significantly increased (P<0.05), the serum LDH, CK-MB and TXA2 levels were significantly decreased (P<0.05), the PGI2 level was significantly increased (P<0.05), the myocardial SOD level was significantly increased (P<0.05), and the myocardial MDA level was significantly decreased (P<0.05); the myocardial Bcl-2 protein level was significantly increased, and the Bax protein level was significantly decreased (P<0.05). Conclusion: Baicalin has protective effects on myocardial infarction in rats. The possible mechanisms may be related to its resistance to oxidative stress, and up-regulation of Bcl-2 protein expression and down-regulation of Bax protein expression in myocardial tissue.

The effects of inhaled NO on plasma vasoactive factor and CTnI level in rabbits with acute massive pulmonary embolism

Abstract Purpose: To investigate changes in the plasma concentrations of cardiac troponin I (CTnI), thromboxane A2 (TXA2), prostaglandin I2 (PGI2) and endothelin-1 (ET-1) in rabbits with massive pulmonary embolism (AMPE) and the impact of nitric oxide inhalation (NOI) on these indices. Methods: A total of 30 Japanese rabbits were used to construct an MPE model and were divided into 3 groups equally (n=10), including an EXP group (undergoing modeling alone), an NOI group (receiving NOI 2 h post-modeling) and a CON group (receiving intravenous physiological saline). Results: In the model group, plasma concentration of CTnI peaked at 16 h following modeling (0.46±0.10 µg/ml) and significantly decreased following NOI. Plasma levels of TXB2, PGI2 and ET-1 peaked at 12, 16 and 8 h following modeling, respectively, and significantly decreased at different time points (0, 2, 4, 8, 12, 16, 20 and 24 h) following NOI. A significant correlation was observed between the peak plasma CTnI concentration and peak TXB2, 6-keto prostaglandin F1α and ET-1 concentrations in the model and NOI groups. Conclusion: Increases in plasma TXA2, PGI2 and ET-1 levels causes myocardial damage in a rabbit model of AMPE; however, NOI effectively down regulates the plasma concentration of these molecules to produce a myocardial-protective effect.

Interrelación del equilibrio tromboxano A2-prostaciclina y su modificación cuando se ingiere aspirina / Interrelation of the balance tromboxano A2-prostaciclina and its modification when aspirin is ingested

Introducción: la aspirina, es usada por su acción antiinflamatoria, analgésica, antipirética y antiagregante plaquetaria. El conocimiento del metabolismo del ácido araquidónico es fundamental para el estomatólogo que basa su trabajo en diagnosticar y tratar procesos inflamatorios en tejidos bucodentales, también por su condición de cirujano debe estar alerta en no realizar intervenciones quirúrgicas en pacientes que estén tomando aspirina, por interrumpir este medicamento la agregación plaquetaria, importante paso de la hemostasia normal. Objetivo: interpretar la interrelación hemostática del tromboxano A2 y la prostaciclina en condiciones fisiológicas, y el resultado de su modificación cuando se ingiere aspirina. Método: PubMed fue empleada como fundamental fuente de búsqueda, que incluyó el conocimiento sobre el fármaco aspirina, la interacción del tromboxano y la prostaclina, y la acción que sobre el equilibrio de estos productos ejerce la aspirina; también se revisaron HINARI, LILACS y Medline. Desarrollo: el ácido araquidónico es un ácido graso poliinsaturado de 20 átomos de carbono (ácido 5, 8, 11, 14-eicosatetraenoico) que procede directamente de la dieta. La relación recíproca entre PG-I2 y el TxA2 constituye un mecanismo finamente equilibrado que sirve para regular la función plaquetaria del ser humano. La utilidad de la aspirina en los pacientes expuestos a trombogénesis se debe, en gran parte, a su capacidad para inhibir la síntesis del TxA2, agente derivado del ácido araquidónico, elemento que se encuentra esterificado a los fosfolípidos de la membrana plaquetaria. El óxido nítrico, igual que la PG-I2, actúa también como vasodilatador e inhibidor de la agregación plaquetaria. Conclusiones: los pacientes que acuden al estomatólogo y por prescripción facultativa están tomando aspirina, tienen su sistema plaquetario inhibido y no pueden sintetizar tromboxano. El proceder quirúrgico por parte del estomatólogo en un paciente que esté ingiriendo aspirina lo expone al desarrollo de hemorragia de causa iatrogénica(AU)

Introduction: aspirin is used by its arachidonic acid is fundamental for the dentist that bases its work on diagnosis and treatment of inflammatory processes, also for its surgeon condition he should be alert to do not carry out surgical interventions in patients that are taking aspirin, because this drug interrupts platelet aggregation, important step of the normal hemostasis. Objective: to interpret the hemostatic interrelation of the tromboxano A2 and the prostaciclina in physiologic conditions and the result of their modification when aspirin is ingested. Method: it was employee as fundamental search source the PubMed, other databases also revised they were HINARI, LILACS, Medline. Was carried out a search that included the knowledge on the drug aspirin, the interaction of the tromboxano and the prostaclina, and the action that it has more than enough the balance of these products it exercises the aspirin. Development: the arachidonic acid is a polyunsaturated fatty acid of 20 atoms of carbon (5, 8, 11, 14-eicosatetraenoic acid) that proceeds directly from diet. The reciprocal relationship between PG-I2 and TxA2 constitutes a finely balanced mechanism that is good to regulate the human being's platelet function. The utility of aspirin in patients exposed to thrombogenesis is largely due to its capacity to inhibit the synthesis of the TxA2, agent derived from arachidonic acid, which is esterified to the phospholipids of the platelet membrane. Nitric oxide, the same as the PG-I 2, also acts as vasodilator and inhibitor of the platelet aggregation. Conclusions: the patients that go to the dentist and for medical prescription are taking aspirin, have their platelet system inhibited and cannot synthesize tromboxane. Surgical processes performed by the dentist in a patient that is ingesting aspirin exposes him to the development of hemorrhage of yatrogenic cause(AU)

O endotélio disfuncionante na hipertensão arterial e no tabagismo / Dysfunctional endothelium in hypertension and smoking

Disfunção endotelial (DE) caracteriza qualquer alteração de atividadenormal do endotélio incluindo atividade vasomotora, proliferaçãocelular, adesão/agregação plaquetária, permeabilidade vascular e a interaçãoleucócitos/parede vascular. Contudo, em repouso o leito arterialexibe um estado basal de vasoconstrição (tônus vascular) modulado pormecanismos de controle centrais (sistema nervoso-simpático), periféricos(sistema renina-angiotensina-aldosterona) e um mecanismo local(endotelial) cuja potência é superior às anteriores. DE na hipertensãoestá relacionada à diminuição da biodisponibilidade de NO por reduçãoda síntese e liberação pela sintase endotelial do óxido nítrico (eNOS)influenciada por fatores genéticos e ambientais como hipóxia, hipofluxo,forças de cisalhamento, redução do substrato L-arginina e seuscofatores, ou inativação do NO resultado da sua ligação com diferentesmoléculas hemoglobina, albumina e, principalmente, sua interação comespécies reativas de oxigênio (estresse oxidativo). DE na hipertensãopode, ainda, estar associada à liberação de substâncias vasoconstritorasderivadas do endotélio como trornboxano-Aç, prostaglândina-Hj,endotelina-l e angotensina-Il. Tabagismo aumenta o risco de eventoscardiovasculares, principalmente quando associado à hipertensão.Nicotina estimula a liberação de catecolarninas e promove lesões noendotélio vascular. Radicais livres e compostos aromáticos diminuema síntese de NO, prejudicando a vasodilatação endotélio-dependente.Tabagismo favorece o crescimento celular por estimulação de fatoresde crescimento do endotélio vascular e inativação do NO por aumentodo estresse oxidativo. Aumento da oxidação das lipoproteínas debaixa densidade (LDL) em fumantes tem efeito sinérgico na adesão emigração de monócitos. Todos esses efeitos deletérios do tabagismono leito vascular também são observados, embora em menor extensão,em tabagistas passivos...

Endothelial dysfunction (ED) characterizes ali changes in the normalactivity ofthe endothelium including vasomotor activity, cell proliferation,platelet adhesion and aggregation, vascular permeability andleukocyte-vascular wall interactions. However, at rest, the arterialbed exhibits a baseline state of vasoconstriction (vascular tone) whichis modulated by central control (sympathetic nervous system) andperipheral mechanisms (Renin angiotensin-aldosterone system) anda local mechanism (endothelial); the latter is the most potent. ED inhypertension is related to decreased bioavailability of nitric oxide(NO) due to its reduced synthesis and release by endothelial nitricoxide synthase (eNOS) regarding genetic and environmental factorssuch as hypoxia, decreased blood flow, shear forces, diminishedL-arginine substrate and its cofactors and NO inactivation as a resultof its binding to different molecules including hemoglobin, albuminand, mainly, its interaction with reactive oxygen species (oxidativestress). ED in hypertension can also be linked to the release of endothelium-derived vasoconstricting substances such as thromboxane-Ai,prostaglandin-H2, endothelin-l and angiotensin-Il. Smoking increasesthe risk of cardiovascular events especially when associated withhypertension. Nicotine stimulates catecholamine release and causesvascular endothelium injury. Free radicais and aromatic compoundsreduce NO synthesis, impairing endothelium-dependent vasodilation.Smoking promotes cell growth by stimulating vascular endotheliumgrowth factors and NO inactivation by increasing oxidative stress.The increased oxidation of low-density lipoproteins ir smokers hasa synergistic effect on monocyte adhesion and migration. All thesedeleterious effects of smoking on the vascular bed are also observed,albeit at a lesser extent, in passive smokers...

Tratamiento específico de la hipertensión arterial pulmonar. Experiencia de la policlínica de hipertensión pulmonardel Hospital Maciel, período 2009-2011 / Specific treatment of pulmonary arterial hypertension. Experience of the pulmonary hypertension clinic at the polyclinic Hospital Maciel, period 2009-2011

Introducción:la hipertensión pulmonar (HP) es una condición hemodinámica definida por un aumento de la presiónarterial pulmonar media (PmAP) 25 mmHg en reposo estimada mediante el cateterismo cardíaco derecho (CCD). Secomunica la experiencia adquirida en el diagnóstico, seguimiento y tratamiento de la hipertensión arterial pulmonar(HAP) y de la HP tromboembólica crónica (HPTEC) de la policlínica de HP del Hospital Maciel. Métodos: se analiza una cohorte de 15 pacientes (2009-2011). Se estimaron la clase funcional (CF), la prueba de caminata de 6 minutos (P6M), la excursión sistólica del plano del anillo tricuspídeo (ESPAT) y la velocidad sistólica pico(Sm). La severidad hemodinámica fue estimada por CCD. Se definió respuesta vasorreactiva aguda (RVA) positiva porel descenso de la PmAP 10 mmHg, alcanzando un valor absoluto 40 mmHg sin cambios o aumento del índice cardíaco (IC). Los datos se expresaron como media ± DS. Se empleó el test de t student pareado para comparar el efecto deltratamiento específico y el test de Kruskal-Wallis para comparaciones entre los grupos, con una p<0,05.Resultados:la edad promedio fue de 43 ± 12 años, 12 (80%) mujeres. Diez (67%) del grupo 1 y 5 (33%) del grupo 4. El20% se presentó en CF I-II y 80% en CF III-IV. El tiempo de seguimiento fue de 19 ± 11 meses. La ESPAT y la Sm basales fueron de 17 ± 7 mm y 11 ± 2 cm/s, respectivamente. La PmAP fue de 54 ± 15 mmHg, la presión auricular derecha 11± 6 mmHg, IC 2,1 ± 0,7 l/min/m2, resistencia vascular pulmonar 1.087 ± 625 dinas.s.cm-5, capacitancia pulmonar 1,3 ±0,6 ml/mmHg. Un paciente presentó RVA positiva. Se empleó sildenafil (100%), bosentan (50%) e iloprost (43%); en71% el tratamiento fue combinado. No se registró hepatotoxicidad por bosentan durante el período de seguimiento. Unpaciente murió por rechazo a recibir tratamiento específico. Los 14 pacientes restantes presentaron una mejoría de laCF (3,0 ± 0,8 versus 2,1 ± 0,8, p<0,05), así como de la P6M ...

Modelo experimental de perfusão pulmonar ex vivo em ratos: avaliação de desempenho de pulmões submetidos à administração de prostaciclina inalada versus parenteral / An experimental rat model of ex vivo lung perfusion for the assessment of lungs after prostacyclin administration: inhaled versus parenteral routes

OBJETIVO: Apresentar um modelo experimental de administração de prostaglandina I2 (PGI2) por via inalatória vs. parenteral e avaliar o desempenho funcional dos pulmões em um sistema de perfusão pulmonar ex vivo. MÉTODOS: Quarenta ratos Wistar foram anestesiados, ventilados, submetidos a laparotomia com ressecção do esterno e anticoagulados. O tronco da artéria pulmonar foi canulado. Todos os animais foram submetidos a ventilação mecânica. Os animais foram randomizados em quatro grupos (10 ratos/grupo): salina nebulizada (SN); salina parenteral (SP); PGI2 nebulizada (PGI2N); e PGI2 parenteral (PGI2P). A dose de PGI2 nos grupos PGI2N e PGI2P foi de 20 e 10 µg/kg, respectivamente. Os blocos cardiopulmonares foram submetidos in situ a perfusão anterógrada com solução de baixo potássio e dextrana a 4ºC via artéria pulmonar, extraídos em bloco e armazenados a 4ºC por 6 h. Os blocos foram ventilados e perfundidos em um sistema ex vivo por 50 min, sendo obtidas medidas de mecânica ventilatória, hemodinâmica e trocas gasosas. RESULTADOS: Houve redução da pressão arterial pulmonar média após a nebulização em todos os grupos (p < 0,001), sem diferença entre os grupos. Na perfusão ex vivo, a mecânica ventilatória não diferiu entre os grupos. Houve redução da capacidade relativa de oxigenação ao longo da perfusão nos grupos SN e SP (p = 0,04), e houve aumento significativo da pressão arterial pulmonar no grupo SN. CONCLUSÕES: O modelo experimental de administração de PGI2 na extração pulmonar é exequível e confiável. Na reperfusão, os resultados de hemodinâmica e de trocas gasosas demonstraram tendência a um melhor desempenho com o uso de PGI2 do que com solução salina.

OBJECTIVE:To present a model of prostaglandin I2 (PGI2) administration (inhaled vs. parenteral) and to assess the functional performance of the lungs in an ex vivo lung perfusion system. METHODS: Forty Wistar rats were anesthetized and placed on mechanical ventilation followed by median sterno-laparotomy and anticoagulation. The main pulmonary artery was cannulated. All animals were maintained on mechanical ventilation and were randomized into four groups (10 rats/group): inhaled saline (IS); parenteral saline (PS); inhaled PGI2 (IPGI2); and parenteral PGI2 (PPGI2). The dose of PGI2 used in the IPGI2 and PPGI2 groups was 20 and 10 µg/kg, respectively. The heart-lung blocks were submitted to antegrade perfusion with a low potassium and dextran solution via the pulmonary artery, followed by en bloc extraction and storage at 4ºC for 6 h. The heart-lung blocks were then ventilated and perfused in an ex vivo lung perfusion system for 50 min. Respiratory mechanics, hemodynamics, and gas exchange were assessed. RESULTS: Mean pulmonary artery pressure following nebulization decreased in all groups (p < 0.001), with no significant differences among the groups. During the ex vivo perfusion, respiratory mechanics did not differ among the groups, although relative oxygenation capacity decreased significantly in the IS and PS groups (p = 0.04), whereas mean pulmonary artery pressure increased significantly in the IS group. CONCLUSIONS: The experimental model of inhaled PGI2 administration during lung extraction is feasible and reliable. During reperfusion, hemodynamics and gas exchange trended toward better performance with the use of PGI2 than that with the use of saline.

Iloprosta reduz o dano colônico na colite isquêmica em ratos / Iloprost reduces colonic injury in ischemic colitis in rats

PURPOSE: Evaluate the effects of iloprost administration in the early period of ischemic colitis and the mechanism that how these effects develop. METHODS: Thirty two Wistar albino female rats with an average weight of 220g were divided into four groups of eight rats. In group 1 the rats were given iloprost and sacrificed after 24 hours and in group 2 they were sacrificed after 24 hours without any iloprost. The rats in group 3 were administrated iloprost and sacrificed after 72 hours and in group 4 they were sacrificed at 72th hour without iloprost. The differences between the groups as tissue damage, vascularization or apoptosis were assessed statistically. RESULTS: Oxidative damage and apoptosis were less pronounced and vascularization was better developed in rats that were given iloprost and sacrificed at 24th hour later in contrast to the rats that were not treated with iloprost. But there was no statistical difference among the groups at 72th hour. CONCLUSION: Iloprost inhibited leucocyte infiltration, decreased proinflammatory cytokines and enhanced angiogenesis so that the oxidative stress and inflammatory response decreased resulting in lesser tissue damage.

OBJETIVO: Avaliar os efeitos da administração de iloprosta no período precoce da colite isquêmica e o mecanismo da evolução destes efeitos. MÉTODOS: Trinta e dois ratos Wistar fêmeas em torno de 220g foram distribuídos em quatro grupos de oito ratos. No grupo 1 administração de iloprosta e sacrificados após 24 horas; no grupo 2 foram sacrificados após 24 horas sem iloprosta; no grupo 3 foi administrado iloprosta e sacrificados após 72 horas; no grupo 4 foram sacrificados após 72 horas sem Iloprosta. As diferenças entre os grupos no referente a dano tecidual. vascularização ou apoptose foi apurada estatisticamente. RESULTADOS: Dano oxidativo e apoptose foram menos acentuados e a vascularização foi melhor nos ratos que receberam iloprosta e sacrificados após 24 horas em contraste com os ratos que não receberam iloprosta. Porém, não houve diferença estatisticamente significante entre os grupos de 72 horas. CONCLUSÃO: Iloprosta inibe infiltração leucocitária, diminui a ação inflamatória de citoquinas e estimula angiogênese resultando em menor dano tecidual.

Exploración de la hemodinámica en la hipertensión pulmonar mediante cateterismo cardíaco derecho / Exploration of hemodynamics in pulmonary hipertension by right heart catherization

El diagnóstico final de hipertensión pulmonar se realizamediante cateterismo cardíaco derecho. Existe hipertensiónpulmonar cuando la presión media en la arteria pulmonarsupera los 25 mmHg en situación basal. Una adecuadaexploración hemodinámica permite encuadrar la hipertensiónpulmonar en algunos de los cinco grupos de la clasificaciónclínica actual. Se dan las recomendaciones para los diferentesespecialistas de cuándo efectuar el cateterismo derecho, quéparámetros se deben de registrar y como realizar e interpretaruna prueba aguda de vasorreactividad en la hipertensiónarterial pulmonar.

The final diagnosis of pulmonary hypertension is made byright heart catheterization. Pulmonary hypertension is presentwhen the average pressure in the pulmonary artery exceeds 25mm Hg at baseline. Proper hemodynamic assessment allowsclassification of pulmonary hypertension into one of five clinicalcategories. Recommendations are provided for specialists, whento conduct right heart catheterization, which parameters mustbe recorded and how to perform and interpret a test for acutevasoreactivity in pulmonary arterial hypertensio.

Hipertensión pulmonar idiopática en pediatría: caso clínico y revisión de la literatura / Idiopathic pulmonary hypertension in pediatric age: a case report and review

Idiopathic pulmonary hypertension is a rare disease in the pediatric age. Symptoms are subtle in first stages delaying diagnosis and resulting in worst outcomes. Therefore pediatricians should be aware of the initial symptoms. We report the case of a 13 years oíd girl, who started with progressive dyspnea 9 months before diagnosis. She was admitted to our hospital because of productive cough, fever and shortness of breath. Chest X ray showed enlargement of right ventricle and pulmonary artery. Echocardiography was suggestive of pulmonary hypertension and the diagnosis was confirmed by cardiac catheterization. Work up far secondary causes of pulmonary hypertension was negative and pulmonary hypertension was considered idiopathic. Treatment with oxygen, diuretics, L-arginine, sildenafil, iloprost and acenocumarol was started with good clinical response.

La hipertensión pulmonar idiopática es de rara ocurrencia en la edad pediátrica siendo los síntomas iniciales muy sutiles e inespecíficos, lo que retarda el diagnóstico empeorando el pronóstico. Se presenta el caso de una niña 13 años, quien comienza con disnea progresiva 9 meses antes del diagnóstico. Ingresa por cuadro de tos húmeda, fiebre y dificultad respiratoria de 3 días de evolución. La radiografía de tórax muestra ventrículo derecho aumentado de tamaño y tronco de la arteria pulmonar prominente sospechándose una probable cardiopatía. Se realiza ecocardiografía que demuestra hipertensión pulmonar, la cual es corroborada por el sondeo cardíaco. Todos los exámenes de laboratorio fueron negativos para causas secundarias, estableciéndose el diagnóstico de hipertensión pulmonar idiopática. Se inicia manejo con oxígeno, diuréticos, L-arginina, sildenafil, iloprost nebulizado y acenocumarol, con lo cual la paciente evoluciona favorablemente.

Producción de prostaciclina en arteria radial de diabéticos: comparación con la vena safena y arteria mamaria interna y su relevancia en el pronóstico de estos bypass coronarios / Prostacyclin production in internal mammary ano radial arteries and saphenous veins of diabetic and non diabetic subjects

Background: Myocardial revascularization surgery has used several vessels as coronary grafts including internal mammary and radial arteries which have a better prognosis than saphenous vein. Their long-term patency has been associated with the reléase of endothelium vasodilator and anti-aggregating producís such as prostacyclin. Diabetes induces endothelial dysfunction and a high number of diabetics require revascularization. Aim: To assess the capacity to synthesize prostacyclin of different vessels from diabetics. Material and methods: Internal mammary and radial arteries and saphenous veins obtained from 10 diabetic and 10 non diabetic patients subjected to coronary artery bypass surgery were studied. The capacity to synthesize prostacyclin was assessed in these vessels measuríng its hydrolysis product, the 6-keto-PGFla by radioimmunoassay. Results: Internal mammary arteries and saphenous veins from diabetics synthesized a lower amount of prostacyclin than those from non-diabetics. The radial artery produced similar amounts of prostacyclin in both groups. This response was associated with an increase of the conversión of the precursor arachidonic acid to prostacyclin. The saturating concentrations of this acid required to achieve the maximal stimulation were higher in the radial artery (20 µM) than in the internal mammary artery and saphenous vein (10 µM), suggesting that the enzymatic activity of the radial artery was not affected by diabetes. Conclusions: The radial artery appears as the best replacement vessel for coronary surgery in diabetics. Its favorable biochemical profile and potential lower long-term occlusion rate may be relevant for a better prognosis of myocardial revascularization in these patients.

Papel del óxido nítrico en la fisiología normal de la vía aérea y sus implicaciones en la fisiopatología de la hipertensión pulmonar / The role of nitric oxide (no) in the normal physiology of the airway and its implications on the pathophysiology of pulmonary hypertension / Papel do óxido nítrico na fisiología normal da via aérea e seus implicações na fisiopatología da hipertensão pulmonar

La hipertensión pulmonar es una patología de la microvasculatura pulmonar, caracterizada por un estado de vasoconstricción, proliferación endotelial, proliferación de músculo liso y trombosis. Se han implicado diversas moléculas en su etiología, demostrándose una producción elevada de agentes vasoconstrictores, mitogénicos, protrombóticos y mediadores proinflamatorios como tromboxano A2, endotelina (ET), el inhibidor del activador del plasminógeno y una menor producción de sustancias vasodilatadoras como la prostaciclina (PGI2) y el óxido nítrico (ON), que en condiciones fisiológicas actúa modulando el tono basal de los vasos pulmonares y también como mediador inflamatorio e inmunomodulador. La histopatología de las lesiones en la hipertensión pulmonar sugiere que el daño en el endotelio y los estímulos proliferativos son procesos fundamentales de su desarrollo, desencadenados por alteraciones en la producción o en la actividad del ON, ocasionados por acumulación de radicales libres que lleva a menor biodisponibilidad del ON. En el presente artículo se revisa el papel que juega el ON en la fisiología normal de la vía aérea y sus implicaciones en la fisiopatología de la hipertensión pulmonar...

Pulmonary hypertension is a disease of the pulmonary microvasculature characterized by vasoconstriction, smooth muscle and endothelial proliferation, and thrombosis. Many molecules have been implicated in the etiology, demonstrating an increased production of vasoconstrictor agents as well as mitogenic, prothrombotic and inflammatory mediators such as tromboxano A2, endothelin (ET), and the inhibitor of the plasminogen activator, together with a low production of vasodilator substances such as prostacyclin (PGI2) and nitric oxide (NO), which in physiological conditions, acts as a modulator of the basal tones of the pulmonary vessels, an inflammatory mediator, and an immunomodulator. The histopathology of the injuries in pulmonary hypertension, triggered by the alteration in the production or activity of NO, which is caused by an accumulation of free radicals that leads to lower bioavailability of NO, suggests that the damage in the endothelium and the proliferative stimulus are fundamental processes for their development. This article reviews the role played by NO in the normal physiology of the airway and its implications on the pathophysiology of pulmonary hypertension...

A hipertensão pulmonar é uma patologia da microvasculatura pulmonar, caracterizada por um estado de vasoconstrição, proliferação endotelial, proliferação de músculo liso e trombose. Implicaram-se diversas moléculas na sua etiologia, demonstrando-se uma produção elevada de agentes vasoconstrictores, miogênicos, pro trombóticos e mediadores proinflamatorios como tromboxano A2, endotelina (ET), o inhibidor do ativador do plasminógeno e uma menor produção de substâncias vasodilatadoras como a prostaciclina (PGI2) e o óxido nítrico (ON), que em condições fisiológicas atua modulando o tom basal dos copos pulmonares e também como mediador inflamatório e inmunomodulador. A histopatológica das lesões na hipertensão pulmonar sugere que o dano no endotélio e os estímulos proliferativos são processos fundamentais de seu desenvolvimento, desencadeados por alterações na produção ou na atividade do ON, ocasionados por acumulação de radicais livres que leva a menor biodisponibilidade do ON...

Effects of acid-base imbalance on vascular reactivity

Acid-base homeostasis maintains systemic arterial pH within a narrow range. Whereas the normal range of pH for clinical laboratories is 7.35-7.45, in vivo pH is maintained within a much narrower range. In clinical and experimental settings, blood pH can vary in response to respiratory or renal impairment. This altered pH promotes changes in vascular smooth muscle tone with impact on circulation and blood pressure control. Changes in pH can be divided into those occurring in the extracellular space (pHo) and those occurring within the intracellular space (pHi), although, extracellular and intracellular compartments influence each other. Consistent with the multiple events involved in the changes in tone produced by altered pHo, including type of vascular bed, several factors and mechanisms, in addition to hydrogen ion concentration, have been suggested to be involved. The scientific literature has many reports concerning acid-base balance and endothelium function, but these concepts are not clear about acid-base disorders and their relations with the three known mechanisms of endothelium-dependent vascular reactivity: nitric oxide (NO/cGMP-dependent), prostacyclin (PGI2/cAMP-dependent) and hyperpolarization. During the last decades, many studies have been published and have given rise to confronting data on acid-base disorder and endothelial function. Therefore, the main proposal of this review is to provide a critical analysis of the state of art and incentivate researchers to develop more studies about these issues.

Tratamiento farmacológico actual de la hipertensión arterial pulmonar / Pharmacological treatment of pulmonary arterial hypertension

Until recent years, pulmonary arterial hypertension was considered as an untreatable disease. However, with the better knowledge in its pathobiology, new drugs have been developed. These new drugs can be divided in three main groups: 1. Prostacyclin analogs (Epoprostenol, iloprost, treprostinil); 2. Endothelin antagonists (Bosentan, sitaxsentan); and 3. Phosphodiesterase-5 inhibitors (Sildenafil). Numerous studies have evaluated the safety and efficacy of these drugs, showing significant improvement in exercise capacity, quality of life and time to worsening. Some of them have even showed a better survival when compared with conventional treatment. Despite these advances, pulmonary arterial hypertension remains an incurable disease, so the focus of new studies is the combination of two or more drugs with a different mechanism of action.