NONO2P, a novel nitric oxide donor, causes vasorelaxation through NO/sGC/PKG pathway, K+ channels opening and SERCA activation.

BACKGROUND & AIMS: The treatment of cardiovascular diseases (CVD) could greatly benefit from using nitric oxide (NO) donors. This study aimed to investigate the mechanisms of action of NONO2P that contribute to the observed responses in the mesenteric artery. The hypothesis was that NONO2P would have similar pharmacological actions to sodium nitroprusside (SNP) and NO. METHODS: Male Wistar rats were euthanized to isolate the superior mesenteric artery for isometric tension recordings. NO levels were measured using the DAF-FM/DA dye, and cyclic guanosine monophosphate (cGMP) levels were determined using a cGMP-ELISA Kit. RESULTS: NONO2P presented a similar maximum efficacy to SNP. The free radical of NO (NO•) scavengers (PTIO; 100 µM and hydroxocobalamin; 30 µM) and nitroxyl anion (NO-) scavenger (L-cysteine; 3 mM) decreased relaxations promoted by NONO2P. The presence of the specific soluble guanylyl cyclase (sGC) inhibitor (ODQ; 10 µM) nearly abolished the vasorelaxation. The cGMP-dependent protein kinase (PKG) inhibition (KT5823; 1 µM) attenuated the NONO2P relaxant effect. The vasorelaxant response was significantly attenuated by blocking inward rectifying K+ channels (Kir), voltage-operated K+ channels (KV), and large conductance Ca2+-activated K+ channels (BKCa). NONO2P-induced relaxation was attenuated by cyclopiazonic acid (10 µM), indicating that sarcoplasmic reticulum Ca2+-ATPase (SERCA) activation is involved in this relaxation. Moreover, NONO2P increased NO levels in endothelial cells and cGMP production. CONCLUSIONS: NONO2P induces vasorelaxation with the same magnitude as SNP, releasing NO• and NO-. Its vasorelaxant effect involves sGC, PKG, K+ channels opening, and SERCA activation, suggesting its potential as a therapeutic option for CVD.

Prediction of adverse cardiac outcomes in high-risk Mexican patients with chest pain in the emergency department / Desenlaces adversos cardiovasculares en pacientes mexicanos de alto riesgo con dolor torácico en el servicio de urgencias

Abstract Objective: The aim of the study was to compare the discriminative power and accuracy for prediction of MACE of five commonly used scoring tools in Mexican patients with chest pain who present to the ED. Methods: A single-center, prospective, observational, and comparative study of patients admitted to the ED with chest pain as the chief complaint. Five chest pain scoring systems were calculated. The primary endpoint was the composite of cardiovascular death, myocardial infarction, coronary intervention, coronary artery bypass grafting, or readmission for cardiovascular causes within 30 days. Results: A total of 168 patients were studied. The score which provided the highest area under the curve of 0.76 (95% CI: 0.70-0.85) was history, ECG, age, risk factors, and troponin (HEART) score. In addition, the integrated discrimination index for the HEART score was 6% higher when compared to the other four scores. Conclusions: The HEART score provided the best classification tool for identifying those patients at highest risk for MACE, either alone or by adding their results to other classification scores, even in a comorbid population.

Resumen Objetivo: Comparar el poder discriminativo y precisión diagnóstica de Eventos Cardiovasculares Mayores (ECVM) de cinco escalas de clasificación de dolor torácico de uso común en pacientes mexicanos con dolor torácico que acuden al servicio de urgencias. Métodos: Estudio prospectivo, observacional y comparativo que incluyó a pacientes ingresados en urgencias que presentaban dolor torácico como síntoma cardinal. Se calcularon cinco escalas de puntuación de dolor torácico. El desenlance principal fue el compuesto de muerte cardiovascular, infarto de miocardio, intervención coronaria, injerto de derivación de arteria coronaria o reingreso por causas cardiovasculares dentro de los 30 días. Resultados: Se estudió un total de 168 pacientes. La escala de puntuación que proporcionó el área bajo la curva más alta de 0.76 (IC de 95%: 0.70-0.85) fue la escala de historia clínica, ECG, edad, factores de riesgo y troponina (HEART, por sus siglas en inglés). Además, el indice de discriminación efectiva para la puntuación HEART fue un 6% más alto en comparación con las otras cuatro escalas de puntuación. Conclusiones: La escala de HEART proporcionó la mejor herramienta de clasificación para idenfiticar a los pacientes con mayor riesgo de ECVM, ya sea solo a agregando sus resultados a otros puntajes de clasificación, incluso en una población comórbida.

Prediction of adverse cardiac outcomes in high-risk Mexican patients with chest pain in the emergency department.

OBJECTIVE: The aim of the study was to compare the discriminative power and accuracy for prediction of MACE of five commonly used scoring tools in Mexican patients with chest pain who present to the ED. METHODS: A single-center, prospective, observational, and comparative study of patients admitted to the ED with chest pain as the chief complaint. Five chest pain scoring systems were calculated. The primary endpoint was the composite of cardiovascular death, myocardial infarction, coronary intervention, coronary artery bypass grafting, or readmission for cardiovascular causes within 30 days. RESULTS: A total of 168 patients were studied. The score which provided the highest area under the curve of 0.76 (95% CI: 0.70-0.85) was history, ECG, age, risk factors, and troponin (HEART) score. In addition, the integrated discrimination index for the HEART score was 6% higher when compared to the other four scores. CONCLUSIONS: The HEART score provided the best classification tool for identifying those patients at highest risk for MACE, either alone or by adding their results to other classification scores, even in a comorbid population.

OBJETIVO: Comparar el poder discriminativo y precisión diagnóstica de Eventos Cardiovasculares Mayores (ECVM) de cinco escalas de clasificación de dolor torácico de uso común en pacientes mexicanos con dolor torácico que acuden al servicio de urgencias. MÉTODOS: Estudio prospectivo, observacional y comparativo que incluyó a pacientes ingresados en urgencias que presentaban dolor torácico como síntoma cardinal. Se calcularon cinco escalas de puntuación de dolor torácico. El desenlance principal fue el compuesto de muerte cardiovascular, infarto de miocardio, intervención coronaria, injerto de derivación de arteria coronaria o reingreso por causas cardiovasculares dentro de los 30 días. RESULTADOS: Se estudió un total de 168 pacientes. La escala de puntuación que proporcionó el área bajo la curva más alta de 0.76 (IC de 95%: 0.70-0.85) fue la escala de historia clínica, ECG, edad, factores de riesgo y troponina (HEART, por sus siglas en inglés). Además, el indice de discriminación efectiva para la puntuación HEART fue un 6% más alto en comparación con las otras cuatro escalas de puntuación. CONCLUSIONES: La escala de HEART proporcionó la mejor herramienta de clasificación para idenfiticar a los pacientes con mayor riesgo de ECVM, ya sea solo a agregando sus resultados a otros puntajes de clasificación, incluso en una población comórbida.

Possible Long-Term Cardiovascular Effects of COVID-19.

Coronavirus Disease 2019 is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and has become a worldwide pandemic. Since 2019, the virus has mutated into multiple variants that have made it harder to eradicate and have increased the rate of infection. This virus can affect the structure and the function of the heart and can lead to cardiovascular symptoms that can have long-lasting effects despite recovery from COVID-19. These symptoms include chest pain, palpitations, fatigue, shortness of breath, rapid heartbeat, arrhythmias, cough and hypotension. These symptoms may persist due to myocardial injury, cardiac inflammation or systemic damage that may have been caused during infection. If these symptoms persist, the patient should visit their cardiologist for diagnosis and treatment plan for any type of cardiovascular disease that may have developed Post-COVID 19.

Cardiovascular responses to pelvic floor muscle contraction in healthy women: Prospective study.

OBJECTIVE: Analyze the acute heart rate and blood pressure responses to two protocols of pelvic floor muscles contractions in premenopausal and postmenopausal women. METHODS: Fifty-four women without pelvic floor muscles disorders were eligible and allocated into two groups: premenopausal and postmenopausal. The groups underwent two protocols and the pelvic floor muscle endurance, heart rate, and blood pressure values were monitored. Both protocols included 10 pelvic floor muscles contractions; one series contained contractions lasting 5 s with 5 s of rest between each contraction and the other series contained contractions lasting 10 s with 10 s of rest. RESULTS: In both groups, there was a significant increase in the heart rate during pelvic floor muscles contractions (premenopausal: 71.0 ± 7.3 and 80.3 ± 7.7; postmenopausal: 65.4 ± 6.6 and 73.6 ± 6.6, at rest and contractions peak, respectively) and in systolic blood pressure immediately after the contractions. The observed values during exercise returned to basal values seconds after the contractions. A positive correlation between heart rate and vaginal squeeze pressure (r = 0.45, p = 0.0007 and r = 0.48, p = 0.0003, 5- and 10-s series, respectively) was observed. CONCLUSION: The proposed protocol of isometric pelvic floor muscles contractions caused an increase in heart rate and blood pressure within the normal range and might not represent a cardiovascular risk for healthy postmenopausal women without urinary incontinence and without cardiovascular dysfunctions.

Urban particulate matter induces the expression of receptors for early and late adhesion molecules on human monocytes.

Exposure to urban particulate matter (PM) is correlated with increases in the emergence of health services due to adverse events and deaths and is mainly related to cardiorespiratory complications. The translocation of particles from the lung into circulation has been proposed as a factor that may trigger systemic effects. Monocytes may be exposed to PM, and if the monocytes are activated, then they are likely to adhere to endothelial cells in a distant organ due to the expression of receptors for adhesion molecules. In the present study, we evaluated the expression of receptors for adhesion molecules (sLex, PSGL-1, LFA-1, VLA-4 and αVß3) in monocytes (U937 cells) exposed for 3 or 18 h to PM10 (0.001, 0.003, 0.010, 0.030, 0.300, 3 or 30 µg/mL). Exposed cells were co-cultured with human endothelial cells that were naive or previously exposed to the same particles. When U937 cells were exposed to PM10, similar levels of expression for early and late receptors for adhesion molecules were observed from 30 ng/mL as those induced by TNF-α. Cells exposed to particles at concentrations above 30 ng/mL were more adhesive to naive or exposed human endothelial cells. Taken together, our results suggest that it is plausible that activated monocytes may play a role in systemic effects induced by PM10 due to the size distribution of the particles and the concentrations required to trigger the expression of receptors for adhesion molecules in monocytes.

Efectos cardiovasculares debido al consumo de cannabinoides / Cardiovascular effects due to the use of cannabinoids

Resumen Objetivo dar a conocer los efectos cardiovasculares secundarios al consumo de marihuana según lo reportado en la literatura médica. Métodos se realizó una búsqueda con los términos MESH "Cannabis", "Marijuana smoking" y "adverse effects" en la base de datos PubMed hasta el año 2016. Se obtuvieron 265 referencias. Se excluyeron cartas de editores, protocolos de investigación en proceso, población pediátrica (menores de 18 años), embarazadas, referencias en idiomas diferentes a inglés y español y se escogieron solo referencias relacionadas con efectos cardiovasculares. Resultados se han establecido dos tipos de receptores de cannabinoides, los CB1 y los CB2, con localizaciones a nivel del sistema nervioso central, endotelial, renal y músculo liso. En la actualidad el consumo de marihuana ha venido en aumento y los médicos poco conocen de sus efectos y los diferentes nombres comerciales para esta sustancia. Existen efectos protectores a nivel vascular con detención de la progresión de la placa aterosclerótica y a la vez múltiples efectos no deseados como taquicardia, hipotensión y bradicardia. Múltiples reportes de caso documentan la relación de la marihuana con el infarto agudo de miocardio con o sin lesión de las arterias coronarias, así como con hemorragia subaracnoidea, pero no existen mecanismos claramente descritos que expliquen una relación directa con estos desenlaces. Conclusiones se conoce la fisiopatología y los receptores donde actúan los cannabinoides generando efectos tanto protectores como dañinos. Existe fuerte correlación con enfermedad cardiovascular, principalmente síndrome coronario agudo, pero el mecanismo fisiopatológico aún no es claro.

Abstract Objective To determine the cardiovascular side-effects of smoking marihuana according to that reported in the medical literature. Methods A search was performed using the MeSH terms, "Cannabis", "Marijuana smoking" and "adverse effects", in the PubMed database up to the year 2016. A total of 265 references were obtained. The exclusion criteria were; Letters to the editor, protocols of research in process, paediatrics (less than 18 years), pregnancy, articles in languages other than English or Spanish. Only references associated with cardiovascular effects were collected. Results Two types of cannabinoid receptors, CB1 and CB2, have been defined and are located in the central nervous system, as well as in endothelial, renal and smooth muscle. The consumption of marijuana is increasing, and doctors know little about its effects, as well as the different marketing names used for this substance. There are protective effects at vascular level, with the slowing down of atherosclerotic plaques, as well as the many undesired effects such as, tachycardia, hypotension, and bradycardia. Many case reports document the association of marijuana with acute myocardial infarction with or without coronary artery lesions, as well as with subarachnoid haemorrhage, but there are no clearly described mechanisms that could explain a direct relationship with these events. Conclusions The pathophysiology is known, as well as where the cannabinoid receptors act to generate their protective and harmful effects. There is a strong association with cardiovascular disease, mainly acute coronary syndrome, but the pathophysiological is still not clear.

Cardiovascular effects of Zumba(®) performed in a virtual environment using XBOX Kinect.

[Purpose] This study evaluated the acute cardiovascular responses during a session of Zumba(®) Fitness in a virtual reality environment. [Subjects] Eighteen healthy volunteers were recruited. [Methods] The following cardiovascular variables: heart rate, systolic blood pressure, diastolic blood pressure, and double product were assessed before and after the practice of virtual Zumba(®), which was performed as a continuous sequence of five choreographed movements lasting for 22 min. The game Zumba Fitness Core(®), with the Kinect-based virtual reality system for the XBOX 360, was used to create the virtual environment. Comparisons were made among mean delta values (delta=post-Zumba(®) minus pre-Zumba(®) values) for systolic and diastolic blood pressure, heart rate, and double product using Student's t-test for paired samples. [Results] After a single session, a significant increase was noted in all the analyzed parameters (Systolic blood pressure=18%; Diastolic blood pressure=13%; Heart rate=67%; and Double product=97%). [Conclusion] The results support the feasibility of the use of Zumba Fitness Core(®) with the Kinect-based virtual reality system for the XBOX 360 in physical activity programs and further favor its indication for this purpose.

Incretins and selective renal sodium-glucose co-transporter 2 inhibitors in hypertension and coronary heart disease.

Hyperglycemia is associated with an increased risk of cardiovascular disease, and the consequences of intensive therapy may depend on the mechanism of the anti-diabetic agent(s) used to achieve a tight control. In animal models, stable analogues of glucagon-like peptide-1 (GLP-1) were able to reduce body weight and blood pressure and also had favorable effects on ischemia following coronary reperfusion. In a similar way, dipeptidyl peptidase IV (DPP-IV) showed to have favorable effects in animal models of ischemia/reperfusion. This could be due to the fact that DPP-IV inhibitors were able to prevent the breakdown of GLP-1 and glucose-dependent insulinotropic polypeptide, but they also decreased the degradation of several vasoactive peptides. Preclinical data for GLP-1, its derivatives and inhibitors of the DPP-IV enzyme degradation suggests that these agents may be able to, besides controlling glycaemia, induce cardio-protective and vasodilator effects. Notwithstanding the many favorable cardiovascular effects of GLP-1/incretins reported in different studies, many questions remain unanswered due the limited number of studies in human beings that aim to examine the effects of GLP-1 on cardiovascular endpoints. For this reason, long-term trials searching for positive cardiovascular effects are now in process, such as the CAROLINA and CARMELINA trials, which are supported by small pilot studies performed in humans (and many more animal studies) with incretin-based therapies. On the other hand, selective renal sodium-glucose co-transporter 2 inhibitors were also evaluated in the prevention of cardiovascular outcomes in type 2 diabetes. However, it is quite early to draw conclusions, since data on cardiovascular outcomes and cardiovascular death are limited and long-term studies are still ongoing. In this review, we will analyze the mechanisms underlying the cardiovascular effects of incretins and, at the same time, we will present a critical position about the real value of these compounds in the cardiovascular system and its protection.

Combination Therapy for the Cardiovascular Effects of Perinatal Lead Exposure in Young and Adult Rats / Alterações cardiovasculares da exposição perinatal ao chumbo em ratos jovens e adultos: papel da terapia combinada

Background: Combination therapy can play a significant role in the amelioration of several toxic effects of lead (Pb) and recovery from associated cardiovascular changes. Objective: To investigate the effects of combination therapy on the cardiovascular effects of perinatal lead exposure in young and adult rats Methods: Female Wistar rats received drinking water with or without 500 ppm of Pb during pregnancy and lactation. Twenty-two- and 70-day-old rat offspring who were or were not exposed to Pb in the perinatal period received meso-dimercaptosuccinic acid (DMSA), L-arginine, or enalapril and a combination of these compounds for 30 additional days. Noradrenaline response curves were plotted for intact and denuded aortas from 23-, 52-, 70-, and 100-day-old rats stratified by perinatal Pb exposure (exposed/unexposed) and treatment received (treated/untreated). Results: Systolic blood pressure was evaluated and shown to be higher in the 23-, 52-, 70-, and 100-day age groups with Pb exposure than in the corresponding control age groups: 117.8 ± 3.9*, 135.2 ± 1.3*, 139.6 ± 1.6*, and 131.7 ± 2.8*, respectively and 107.1 ± 1.8, 118.8 ± 2.1, 126.1 ± 1.1, and 120.5 ± 2.2, respectively (p < 0.05). Increased reactivity to noradrenaline was observed in intact, but not denuded, aortas from 52-, 70-, and 100-day-old exposed rats, and the maximum responses (g of tension) in the respective Pb-exposed and control age groups were as follows: 3.43 ± 0.16*, 4.32 ± 0.18*, and 4.21 ± 0.23*, respectively and 2.38 ± 0.33, 3.37 ± 0.13, and 3.22 ± 0.21, respectively (p < 0.05). Conclusions: All treatments reversed the changes in vascular reactivity to noradrenaline in rats perinatally exposed to Pb. The combination therapy resulted in an earlier restoration of blood pressure in Pb-exposed rats compared with the monotherapies, except for enalapril therapy in young rats. These ...

Introdução: A terapia combinada parece desempenhar papel significativo em reduzir os efeitos cardiovasculares deletérios da exposição ao chumbo (Pb). Objetivo: Para investigar esta possibilidade, ratas Wistar receberam Pb (500 ppm na água de beber) ou água durante a prenhez e a lactação. Ratos com 22 e 70 dias, expostos perinatalmente ao Pb ou não, receberam DMSA, L- arginina, enalapril e a combinação destes por 30 dias adicionais. Métodos: Curvas concentração-efeito à noradrenalina foram obtidas em aortas intactas e desnudas, de ratos com 23, 52, 70 e 100 dias expostos ou não ao Pb, tratados ou não. Resultados: A pressão arterial sistólica caudal (mmHg) foi avaliada e mostrou-se aumentada em ratos expostos ao Pb [23, 52, 70 e 100 dias, respectivamente: controle 107,1±1,8, 118,8±2,1, 126,1±1,1, 120,5±2,2; Pb 117,8±3,9*, 135,2±1,3*, 139,6±1,6* e 131,7± 2,8*]. Observou-se aumento de reatividade à noradrenalina em aorta intacta, mas não desnudada, de ratos com 52, 70 e 100 dias expostos ao Pb [resposta máxima (g de tensão) 52 dias: Pb 3,43±0,16*, controle 2,38±0,33; 70 dias: Pb 4,32±0,18*, controle 3,37±0,13; 100 dias: Pb 4,21±0,23*, controle 3,22±0,21]. (*) p < 0,05 em relação ao respectivo controle. Conclusões: Todos os tratamentos restauraram as alterações de reatividade à noradrenalina em aortas de ratos expostos perinatalmente ao Pb. Exceto pelo enalapril em ratos jovens, a terapia combinada restaurou mais precocemente a pressão arterial de ratos expostos ao Pb em relação aos tratamentos isolados. Estes resultados representam uma nova abordagem no desenvolvimento de protocolos terapêuticos no tratamento da hipertensão induzida pela exposição ao Pb. .

Chemical composition and cardiovascular effects induced by the essential oil of Cymbopogon citratus DC. Stapf, Poaceae, in rats / Composição química e efeitos cardiovasculares do óleo essencial de Cymbopogon citratus DC. Stapf, Poaceae, em ratos

Cymbopogon citratus DC. Stapf, Poaceae, is used in the folk medicine for hypertension treatment. This work investigated the chemical composition and cardiovascular effects in rats of C. citratus essential oil (EOCC). A phytochemical screening demonstrated the presence of eight constituents, being geranial the major compound (43.08 percent). In rats, EOCC (1, 5, 10, and 20 mg/kg, i.v.) induced transient hypotension and bradycardia that were attenuated by atropine and sodium thiopental, but not by L-NAME or indomethacin. In rings of rat superior mesenteric artery pre-contracted with phenylephrine, EOCC (1 to 3000 µg/mL) induced relaxation that was not affected after removal of the endothelium, after TEA or in rings pre-contracted with KCl (80 mM). Furthermore, EOCC (1000 µg/mL) was not able to induce additional effect on maximal relaxation of nifedipine (10 µM). In conclusions, EOCC induces hypotension, possibly by reduction in vascular resistance caused by inhibition of the Ca2+ influx, and bradycardia probably due to an activation of cardiac muscarinic receptors.

C. citratus é utilizada na medicina popular para tratar hipertensão. Este trabalho investigou a composição química e os efeitos cardiovasculares do óleo essencial do C. citratus (OECC). Foram identificados oito constituintes no OECC, sendo geranial o majoritário (43,08 por cento). Em ratos, o OECC (1, 5, 10 e 20 mg/kg, i.v.) induziu hipotensão e bradicardia que foram atenuadas pela atropina e tiopental sódico, mas não por L-NAME ou indometacina. Em anéis de artéria mesentérica de ratos pré-contraídos com fenilefrina, o OECC (1 a 3000 µg/mL) induziu relaxamento que não foi afetado após remoção do endotélio, após TEA ou em anéis pré-contraídos com KCl (80 mM). Além disso, o OECC (1000 µg/mL) não induziu efeito adicional sobre o relaxamento máximo da nifedipina (10 µM). Em conclusão, o OECC induz hipotensão possivelmente devido à redução da resistência vascular que pode ser causada por inibição do influxo de Ca2+, e bradicardia provavelmente devido à ativação de receptores muscarínicos cardíacos.

Cardiovascular effects induced by the hydroalcoholic extract of the stem of Xylopia cayennensis in rats / Efeitos cardiovasculares induzidos pelo extrato hidroalcoólico das cascas de Xylopia cayennensis em ratos

The cardiovascular effects induced by the hydroalcoholic extract of the stem of Xylopia cayennensis (HEXC) were studied in rats using a combined in vivo and in vitro approach. In non-anesthetized rats, HEXC injections produced a significant and dose-dependent hypotension associated with an increase in heart rate. The hypotensive response was not attenuated after nitric oxide (NO) synthase blockade, L-NAME (20 mg/Kg, i.v.). In isolated rat superior aortic rings, HEXC was able to relax the tonus induced by phenylephrine (1 µM) and KCl (80 mM), (EC50 = 85±13 and 62±5 µg/mL, respectively). The smooth muscle-relaxant activity of HEXC was not inhibited by removal of vascular endothelium (EC50 = 58±6 µg/mL). HEXC antagonized CaCl2-induced contractions in depolarizing medium nominally without Ca2+. HEXC inhibited the intracellular calcium-dependent transient contractions induced by caffeine (20 mM) in Ca2+-free solution, but not those induced by norepinephrine (1 µM). In isolated rat atrial preparations, HEXC produced negative inotropic and chronotropic responses (IC50= 534±42 and 259±22 µg/mL, respectively). The results obtained suggest that the hypotensive effect of HEXC is probably due to a peripheral vasodilatation, at least, secondary to an interference with the Ca2+ mobilization as a consequence of voltage-dependent Ca2+ channel blockade and the inhibition of Ca2+ release from caffeine-sensitive intracellular stores. Finally, HEXC acts directly on the heart decreasing contractility and heart rate, these effects are of little importance to the expression of the hypotensive response induced by HEXC.

Os efeitos cardiovasculares induzidos pelo extrato hidroalcoólico do caule de Xylopia cayennensis (EHXC) foram estudados em ratos, utilizando uma abordagem combinada in vivo e in vitro. Em ratos não anestesiados, EHXC induziu uma hipotensão não dependente de dose associada com um aumento da freqüência cardíaca. Esta resposta hipontesora não foi atenuada depois do bloqueio com L-NAME (20 mg/Kg, i.v.). Em anéis de aorta isolados de rato, EHXC foi capaz de relaxar o tônus induzido por fenilefrina (1 µM) e KCl (80 mM), (CE50 = 85±13 e 62±5 µg/mL, respectivamente). A atividade vasorelaxante do HEXC não foi inibida pela remoção do endotélio vascular (CE50 = 58±6 µg/mL). HEXC antagonizou as contrações induzidas por CaCl2 em meio despolarizante nominalmente sem Ca+2. EHXC antagonizou de maneira dependente de concentração as contrações transientes induzidas por cafeína (20 mM), em meio livre de Ca2+, contudo não alterou aquelas induzidas por noradrenalina (1 µM). Em átrio isolado de rato, EHXC induziu um efeito inotrópico e cronotrópico negativo (CI50= 534±42 µg/mL e 259±22 µg/mL; respectivamente). Os resultados obtidos demonstram que EHXC apresenta um potente efeito hipotensor, provavelmente conseqüência da diminuição da resistência periférica total que parece ser, em parte, devido a uma ação inibitória sobre o influxo de Ca+2 através de canais de cálcio dependentes de voltagem e também através da inibição da liberação de Ca+2 dos estoques intracelulares sensíveis à cafeína. HEXC atua diretamente no coração diminuindo a contratilidade e a freqüência cardíaca, estes efeitos têm importância pequena na expressão da resposta hipotensiva induzida por HEXC.

Estudio comparativo entre bupivacaina + fentanyl vs. Bupivacaina sola por vía peridural para el control del dolor obstétrico / A comparative study between bupivacaine + fentanyl vs. Bupivacine alone for a peridural to control obstetric pain

Objetivo: Evaluar la calidad y duración de la analgesia obstétrica que se obtiene al utilizar bupivacaína + fentanyl, en comparación a cuando solo se utiliza bupivacaína.Método: Se realizó un estudio comparativo, prospectivo, longitudinal, evaluándose 120 pacientes, las cuales fueron divididas en 2 grupos: Grupo A: Bupivacaína 20mg + Fentanyl 50ucg y Grupo B: Bupivacaína sola 20mg, vía peridural administrados en embarazadas de 38 a 40 semanas de gestación. Los datos fueron recolectados mediante un formato, en el cual se incluyó valoración del dolor (EVA), Frecuencia cardiaca (FC),Tensión Arterial Sistólica (TAS), Tensión Arterial Diastólica (TAD), Presión Arterial Media (PAM), Frecuencia Cardiaca Fetal (FCF).Resultados: En el presente estudio la edad promedio fue de 25años (28%), la mayoría primigestas (54.5%), con una dilatación promedio de 6 cm. (37.5%), valoradas preanestésicamente con ASA 1 (95%), y ASA 2 (5%), para ambos grupos; se valoró la EVA (escala visual análoga de dolor) siendo de 10 (valor máximo) al inicio del estudio y a los 45 minutos 0 para el grupo A y 2 para el grupo B.Conclusiones: La administración de narcóticos por vía peridural, con fines de analgesia, es una técnica que ha dado excelentes resultados, especialmente en el ámbito médico, en el campo de la obstetricia, ya que ha demostrado ser una técnica muy efectiva para el control del dolor en el trabajo de parto.

Objectives: To evaluate the quality and duration of the obstetric analgesic that is obtained by using bupivacaine + fetanyl in comparison to just using bupivacaine.Method: A comparative, prospective, longitudinal study was done in with 120 patients were divided in two groups:1.Group A: Bupivacaine 20 mg + Fentanyl 50ucg2.Group B: Bupivacaine 20 mg aloneIn which it was administered by peridural in expecting women in there 38 – 40 week.The data was collected using a format with include evaluating the visual analog pain scale, heart rate, Systolic pressure, Diastolic Pressure, mean arterial blood pressure and fetal heart rate.Results: In this study the average age is 25 years old (28%), the majority were primipara 54.5% with a dilatation of 6 cm (37.5%). When analyzed pre- anesthesia with an ASA 1 (95%) and ASA 2 (5%). For both groups we evaluated the visual analog pain scale being 10 the maximum score at the beginning and after 45 minutes 0 for group A and 2 for group B.

QT-interval dispersion in malnourished children.

BACKGROUND: Little is known about the electrocardiographic (ECG) QT interval and its variability in malnourished children. HYPOTHESIS: The study of the QT interval and its dispersion in malnourished children was undertaken to determine whether the QT interval and its variability are increased in these children. METHODS: In 40 children (20 malnourished and 20 controls) aged 12.2 +/- 14.4 months (23 male) a conventional ECG was performed for computing heart rate, heart rate variability, corrected QT interval, and QT-interval dispersion. A blood sample was obtained for measuring hemoglobin, hematocrit, plasma protein, and plasma electrolytic concentrations. RESULTS: Corrected heart rate, heart rate variability, and QT Interval were similar in both groups. When compared with the control group, the malnourished children had greater corrected QT-interval dispersion, and that dispersion was more accentuated in the precordial leads. They also had repolarization abnormalities (flattened or inverted T waves and U waves). Hemoglobin, hematocrit, plasma protein, and plasma electrolytic concentrations were lower in the malnourished children. However, the ECG findings showed no statistically significant relationship with either the blood parameters, the severity or type of malnutrition, and the size or the weight of the children. CONCLUSIONS: QT-interval dispersion is increased in malnourished children and the dispersion is more accentuated in the precordial leads.

PIP: This study aims to determine electrocardiogram (ECG) QT-interval dispersion and its variability in malnourished children of Venezuela. The sample population consisted of 40 children (20 malnourished and 20 well nourished). A conventional ECG was performed for computing the heart rate, heart rate variability, corrected QT-interval, and QT-interval dispersion. In addition, blood samples were obtained to measure hemoglobin, hematocrit, plasma protein, and plasma electrolyte concentrations. Findings showed that the corrected heart rate, heart rate variability, and QT-interval were similar in malnourished and well-nourished children. Moreover, malnourished children demonstrated a greater corrected QT-interval dispersion and that dispersion was more accentuated in the precordial leads. They also had repolarization abnormalities (flattened or inverted T waves and U waves). Hemoglobin, hematocrit, plasma protein, and plasma electrolyte concentrations were lower in malnourished children. However, the ECG findings showed no statistical significant relationship with either blood parameters, the severity or type of malnutrition, and the size or the weight of the children.

[Contraceptive use in women with heart disease]. / Uso de contraceptivos em portadoras de cardiopatia.

PURPOSE: To analyse efficacy, tolerance and adverse events of reversible contraceptives in women with cardiac disease. METHODS: We studied prospectively during 24-39 (mean = 29) months, 89 women with heart disease with a mean age of 25.6 (16-42) years. Rheumatic heart disease was present in 73 (82%) cases, congenital heart disease in 11 (11%), coronary artery disease in 2 (2%) and cardiomyopathy in 3 (3%) case. The patients were divided in three groups: GCO--35 patients taking combined oral contraceptives (30 micrograms ethinyl estradiol and 75 micrograms gestodene--COs); GIT--27 using injectable progestagens (depot medroxyprogesterone acetate-DMPA) and GUID--27 with intrauterine device (IUD). RESULTS: In GCO occurred 4 (11.4%) cases of arterial hypertension, 1 (2.8%) of a transient cerebral isquemic attack, 3 (8.5%) of spotting, 1 (2.8%) of amnorrhea e 1 (2.8%) pregnancy. Interruption of this method occurred in 4 (11.4%) cases due to hypertension (2), pregnancy (1) and amenorrhea (1). In group GIT there were 2 (7.4%) cases of arterial hypertension, 18 (66.6%) of amenorrhea, and 3 (11.1%) of spotting. Interruption of use occurred in 5 (18.5%) due to amnorrhea (2), weight gain (2) and headache (1). In GUID there was 1 (3.7%) case of infeccion, 1 (3.7%) pregnancy and 1 (3.7%) spontaneous expulsion of IUD. Interruption of use took place in 3 (11.1%) cases due to infeccion, pregnancy and expulsion. The comparation between the groups demonstrated a difference in the incidence of amenorrhea (p < 0.005) and descontinuation of use of the method (p < 0.025). CONCLUSION: Use of reversible contraceptives in heart disease women was associated with an acceptable cardiovascular risk. Efficacy and side effects of the methods were comparable in the groups, however intolerance was more observed in GIT.

PIP: The aim of this study was to analyze efficacy, tolerance, and adverse events of reversible contraceptives in women with cardiac disease. The authors studied prospectively, during a period of 24-39 (mean = 29) months, 89 women with heart disease of mean age 25.6 (16-42) years. Rheumatic heart disease was present in 73 cases (82%), congenital heart disease in 11 (11%), coronary artery disease in 2 (2%), and cardiomyopathy in 3 (3%). The patients were divided into three groups: GCO--35 patients taking combined oral contraceptives (30 mcg ethinyl estradiol and 75 mg gestodene); GIT--27 patients using injectable progestagens (depot medroxyprogesterone acetate); and GUID--27 patients with IUDs. In the GCO group were found 4 cases (11.4%) of arterial hypertension, 1 (2.8%) of a transient cerebral ischemic attack, 3 (8.5%) of spotting, 1 (2.8%) of amenorrhea, and 1 (2.8%) of pregnancy. Interruption of this method occurred in 4 cases (11.4%): 2 due to hypertension, 1 due to pregnancy, and 1 due to amenorrhea. In the GIT group there were 2 cases (7.4%) of arterial hypertension, 18 (66.6%) of amenorrhea, and 3 (11.1%) of spotting. Interruption of use occurred in 5 cases (18.5%): 2 due to amenorrhea, 2 due to weight gain, and 1 due to headache. In the GUID group there was 1 case (3.7%) of infection, 1 (3.7%) of pregnancy, and 1 (3.7%) of spontaneous expulsion of the IUD. Interruption of use took place in 3 cases (11.1%): 1 due to infection, 1 due to pregnancy, and 1 due to expulsion. The comparison between the groups demonstrated a difference in the incidence of amenorrhea (p 0.005) and method discontinuation (p 0.025). Use of reversible contraceptives in women with heart disease was associated with an acceptable cardiovascular risk. Efficacy and side effects of the methods were comparable in the groups; however, intolerance was observed more in the GIT group. (author's modified)

[Let's talk about Norplant: advances in steroidal contraception]. / Hablemos del Norplant: avances en anticoncepcion esteroidea.

PIP: Norplant, the subdermal levonorgestrel-releasing contraceptive implant, has undergone 28 years of study, clinical trials, and use by the general population. Its great advantage over combined oral contraceptives (OCs) is that it is free of estrogen and thus acceptable for use by many women with contraindications to estrogen. Norplant has few or no apparent effects on cholesterol, phospholipid, or triglyceride levels, and there is no evidence that Norplant use increases cardiovascular risk. Norplant releases a constant dose of levonorgestrel that varies from 350 ng initially to 290 ng after 5 years of use. The levonorgestrel is released directly into the circulation, avoiding the first hepatic passage. Norplant achieves its contraceptive effect by inhibiting the positive feedback exercised by estradiol on the hypothalamus and thus reducing levels of luteinizing hormone and follicle stimulating hormone, by rendering the cervical mucus inhospitable to passage of sperm, and by altering the composition of the endometrial tissue. It has been suggested that Norplant may affect tubal motility, but no studies in support of this hypothesis have been found. Secondary effects of Norplant use include decreased secretion of gonadotropins and consequently decreased frequency of ovulation, impaired luteal function, migraine or tension headaches, and occasionally such effects as facial chloasma or alterations in libido. The most frequent complications are dysfunctional uterine bleeding and irregular staining and spotting or amenorrhea. 70% of women experience such alterations of menstrual pattern with Norplant over 5 years of use. Norplant is contraindicated for diabetic women because of possible alterations in carbohydrate metabolism. Women who use certain antiepileptic or antitubercular drugs or barbiturates that affect the action of levonorgestrel should choose a nonhormonal contraceptive method. Acute or chronic cholestatic hepatic disease is an absolute contraindication. Although studies of the effects of Norplant on breastfeeding have not conclusively demonstrated any risks, the problem of steroid transfer to the infant through the breast milk has not yet been resolved. Several studies have confirmed the contraceptive efficacy of Norplant and calculated its failure rate at 2%, which makes it the second most effective method after sterilization. The rate of ectopic pregnancy is low. The implants should be inserted under aseptic conditions similar to those observed during any surgical procedure. Once the implants are removed, the serum concentrations of levonorgestrel decline rapidly. Most of the steroid is eliminated within days. Fecundity returns in the cycle following removal. 85% of women conceive within the 1st year after removal and 95% do so within 2 years.^ieng

Tendencies in adult mortality in Rio Grande do Sul, Brazil, 1970-1985. An international comparison.

"In order to evaluate mortality trends in adults aged 30-69 years in the State of Rio Grande do Sul [Brazil], changes in age-standardized mortality from 1970 to 1985 were calculated and compared with trends of 33 other countries. Virtual stability in Rio Grande do Sul over this 16-year period contrasts with dramatic reduction in age-standardized all-cause and cardiovascular disease mortality in many countries.... The data demonstrate that major declines in adult mortality can be achieved, and suggest that, during the period 1970-1985, Rio Grande do Sul participated little in the international tendency toward improved adult health." (SUMMARY IN POR)

Clinical and epidemiologic studies of Chagas' disease in rural communities of Oaxaca, Mexico, and an eight-year followup: II. Chila.

A seroepidemiologic survey conducted in 1971 in the rural Pacific coastal community of Chila in the Mexican state of Oaxaca showed an unusually high prevalence of antibody against the Chagas' disease agent Trypanosoma cruzi. Further studies were undertaken in 1973 and 1981 to (1) determine the pathologic impact of T. cruzi infection in humans, (2) investigate the natural history of the disease, (3) confirm that serologically positive persons were parasitologically positive, and (4) evaluate whether T. cruzi transmission continued into the next decade. This article reports results derived from those studies.

PIP: In 1971, health workers drew blood samples from 238 people living in the rural Pacific coastal village of Chile in Oaxaca State, Mexico to determine seroprevalence of antibodies against Trypanosoma cruzi--the parasite responsible for Chagas' disease. Seroprevalence was 5% in 16 year old children, but increased from 41% to 62% to a peak of 78% for 16-19, 20-29, and 30-39 year olds respectively then fell to 68% for 40-49 year olds only to climb again to 75% in 50-59 year olds and fell again to 47% for =or 60 year olds. Overall seroprevalence for adults was 67%. By 1981, adult seroprevalence had fallen to 33% and childhood prevalence to 0.7%. The very low levels of T. cruzi antibodies in children corresponded with insecticide (DDT) spraying for malaria control and with the disappearance of triatomine bugs from Chile. Medical histories revealed that seropositive individuals were more likely to exhibit acute signs and symptoms of initial bite lesions (Romana's sign), furuncle like skin lesions (Chagoma), and facial or body edema (p.05). They also tended to suffer from chronic fatigue and difficult breathing while lying down (p.05). 1973 electrocardiogram (ECG) results showed that seropositive individuals were significantly more likely to have complete right bundle branch block (p.005) and premature ventricular contractions (p.05) than seronegative individuals. There were no seroconversions among 57 people examined with ECGs between 1971-1983. Even though more seropositives (21%) experienced a progression of ECG abnormalities (3% rate/year) than seronegatives (7%), the difference was not significant. Despite reductions in seroprevalence and in triatomine bug population, serologic surveillance and monitoring to detect repopulation of houses by the bugs should be maintained.

AIDS and the heart in the Caribbean: a silent entity.

PIP: Autopsies were performed by the cardiac pathology laboratory of 74 of 100 consecutive AIDS patients who died in Puerto Rico. The 32 with cardiac pathology are reviewed here. There were 27 males and 5 females, averaging 33 years old. 84% were heroin users and/or homosexual, and of the remaining 16%, 2 had heroin users and/or homosexual, and of the remaining 16%, 2 had received blood transfusions. The immediate cause of death was either respiratory or nervous system failure. One case of pericardial effusion (300 ml) associated with pleural effusion and ascites was found, but it was not clinically evident. 6 had cardiomegaly defined by cardiac mass 350 gm in males or 300 gm in females. There were no EKG findings other than sinus tachycardia with occasional ventricular premature beats. The most common pathological finding was nonspecific myocarditis. There were 5 cases with histoplasma showing cardiac foci of histiocytes, 3 with cardiac toxoplasma foci, 3 with mycobacterium granulomas in the myocardium or pericardium, 2 with cytomegalovirus myocarditis with intranuclear inclusions, 2 with cryptococcus neoformans, and 1 with atypical mycobacteria in the myocardium. 2 additional patients had coagulation necrosis of myocardial fibers. These results indicate that myocarditis is common in AIDS patients in Puerto Rico, especially in intravenous heroin users, and its causes are multiple. The clinical picture in terms of congestive heart failure or arrhythmias, however, is silent.^ieng

[Mortality in the city of Cordoba, Argentina, between 1869 and 1990]. / La mortalidad en la ciudad de Cordoba (Argentina) entre 1869 y 1990.

PIP: Mortality levels and trends for the city of Cordoba, Argentina, from 1869 to 1990 are reviewed. The author notes that during the first half of the period, the major causes of death among the young were infectious and parasitic diseases, while cardiovascular disease and neoplasms among the elderly have predominated in recent years. She makes some comparisons with mortality levels for the country as a whole. A set of mortality tables for the city is included.^ieng