Intra-aortic balloon pump in cardiogenic shock: state of the art.

The clinical definition of cardiogenic shock is that of a low cardiac output and evidence of tissue hypoxia in the presence of adequate blood volume. Cardiogenic shock is the main cause of death related to acute myocardial infarction (AMI), with a mortality rate of 45-70% in the absence of aggressive and highly specialized technical care. The intra-aortic balloon pump (IABP) is one of the most widely used mechanical assisting devices. During the last two decades, about 42% of patients with AMI who evolved with cardiogenic shock received mechanical circulatory assistance with IABP. Its clinical indication has been based on non-randomized studies and registry data. Recent studies have shown that the use of IABP did not reduce 30-day mortality in patients with AMI and cardiogenic shock treated with the strategy of early myocardial revascularization as the planned primary objective. The guidelines of the American Heart Association and of the European Society of Cardiology have reassessed their recommendations based on the results of meta-analyzes, including the IABP-SCHOCK II Trial study, which did not evidence an increase in survival of patients who received mechanical support with IABP. This review article addresses the clinical impact of IABP use in the cardiogenic shock caused by AMI. RESUMO A definição clínica de choque cardiogênico é a de um quadro de baixo débito cardíaco e evidência de hipóxia tecidual, na presença de volemia adequada. O choque cardiogênico representa a principal causa de óbito relacionada ao infarto agudo do miocárdio (IAM), com índice de mortalidade em torno de 45% a 70%, na ausência de cuidados técnicos agressivos e altamente especializados. O balão intra-aórtico (BIA) é um dos dispositivos de assistência mecânica mais utilizados no mundo. Nas duas últimas décadas, cerca de 42% dos pacientes com IAM, que evoluíram com choque cardiogênico, receberam assistência circulatória mecânica com BIA. Sua indicação clínica tem sido baseada em estudos não randomizados e dados de registro. Estudos recentes têm demonstrado que o uso do BIA não reduziu a mortalidade hospitalar (30 dias) em pacientes com IAM e choque cardiogênico, tratados com a estratégia de revascularização precoce do miocárdio como objetivo primário planejado. As diretrizes da Associação Americana de Cardiologia e da Sociedade Europeia de Cardiologia reavaliaram suas recomendações, baseadas nos resultados de metanálises, incluindo o estudo IABP-SCHOCK II Trial, que não evidenciou aumento na sobrevida de pacientes que receberam suporte mecânico com BIA. Este artigo de revisão aborda o impacto clínico do uso do BIA no choque cardiogênico ocasionado pelo IAM.

Intra-aortic balloon pump in cardiogenic shock: state of the art / Balão intra-aórtico no choque cardiogênico: o estado da arte

ABSTRACT The clinical definition of cardiogenic shock is that of a low cardiac output and evidence of tissue hypoxia in the presence of adequate blood volume. Cardiogenic shock is the main cause of death related to acute myocardial infarction (AMI), with a mortality rate of 45-70% in the absence of aggressive and highly specialized technical care. The intra-aortic balloon pump (IABP) is one of the most widely used mechanical assisting devices. During the last two decades, about 42% of patients with AMI who evolved with cardiogenic shock received mechanical circulatory assistance with IABP. Its clinical indication has been based on non-randomized studies and registry data. Recent studies have shown that the use of IABP did not reduce 30-day mortality in patients with AMI and cardiogenic shock treated with the strategy of early myocardial revascularization as the planned primary objective. The guidelines of the American Heart Association and of the European Society of Cardiology have reassessed their recommendations based on the results of meta-analyzes, including the IABP-SCHOCK II Trial study, which did not evidence an increase in survival of patients who received mechanical support with IABP. This review article addresses the clinical impact of IABP use in the cardiogenic shock caused by AMI.

RESUMO A definição clínica de choque cardiogênico é a de um quadro de baixo débito cardíaco e evidência de hipóxia tecidual, na presença de volemia adequada. O choque cardiogênico representa a principal causa de óbito relacionada ao infarto agudo do miocárdio (IAM), com índice de mortalidade em torno de 45% a 70%, na ausência de cuidados técnicos agressivos e altamente especializados. O balão intra-aórtico (BIA) é um dos dispositivos de assistência mecânica mais utilizados no mundo. Nas duas últimas décadas, cerca de 42% dos pacientes com IAM, que evoluíram com choque cardiogênico, receberam assistência circulatória mecânica com BIA. Sua indicação clínica tem sido baseada em estudos não randomizados e dados de registro. Estudos recentes têm demonstrado que o uso do BIA não reduziu a mortalidade hospitalar (30 dias) em pacientes com IAM e choque cardiogênico, tratados com a estratégia de revascularização precoce do miocárdio como objetivo primário planejado. As diretrizes da Associação Americana de Cardiologia e da Sociedade Europeia de Cardiologia reavaliaram suas recomendações, baseadas nos resultados de metanálises, incluindo o estudo IABP-SCHOCK II Trial, que não evidenciou aumento na sobrevida de pacientes que receberam suporte mecânico com BIA. Este artigo de revisão aborda o impacto clínico do uso do BIA no choque cardiogênico ocasionado pelo IAM.

Can total bronchopleural fistulas from complete stump dehiscence be endoscopically treated?

Objectives: Bronchopleural fistula (BPF) is an uncommon complication following a lung resection to address various conditions. BPFs are associated with high morbidity and mortality rates. This study evaluated the endoscopic treatment of 'total' BPFs using the Occlutech-Fígulla® cardiac device at a single centre. Methods: We selected nine patients with chronic and complete BPFs. Under direct bronchoscopic visualization, the BPFs were treated using the Occlutech-Fígulla device. The patients were followed up for 12 months to determine the treatment level and complications. Results: The procedure had a favourable outcome in three patients, resulting in complete fistula closure. Two patients had partial closure and showed improvements in their clinical conditions. In two other cases, closure of the bronchial stump was unsuccessful using this method. Two patients died from causes unrelated to the procedure or the device. During the follow-up period, no complications related to infection or device-related injuries were reported. Conclusions: In patients without clinical conditions that require surgical treatment, the Occlutech-Fígulla cardiac device can be a safe and effective method for the endoscopic treatment of large BPFs resulting from complete dehiscence of a bronchial stump. No severe events were reported.

The echocardiography in the cardiovascular laboratory: a guide to research with animals.

The feasibility and potential for the morphological and hemodynamic investigation of the heart has been increasing the use of the echocardiography in the research setting. Additionally, the development of new technologies, like the real time 3D echocardiography and speckle tracking, demands validation throughout experimental studies before being instituted in the clinical setting. This paper aims to provide information concerning the particularities of the echocardiographic examination in quadruped mammals, targeting the experimental research.

A ecocardiografia no laboratorio cardiovascular: um guia para a pesquisa com animais / The echocardiography in the cardiovascular laboratory: a guide to research with animals

A exequibilidade e o potencial para investigar o coração, sob o ponto de vista morfológico e hemodinâmico, vêm aumentando a aplicação da ecocardiografia na pesquisa. Além disso, o desenvolvimento de novas tecnologias, tais como a ecocardiografia tridimensional em tempo real e o speckle tracking, requerem validação por meio de estudos experimentais antes de serem instituídas no cenário clínico. O presente artigo objetiva fornecer informações acerca das particularidades do estudo ecocardiográfico nos mamíferos quadrúpedes, com vistas à pesquisa experimental.

The feasibility and potential for the morphological and hemodynamic investigation of the heart has been increasing the use of the echocardiography in the research setting. Additionally, the development of new technologies, like the real time 3D echocardiography and speckle tracking, demands validation throughout experimental studies before being instituted in the clinical setting. This paper aims to provide information concerning the particularities of the echocardiographic examination in quadruped mammals, targeting the experimental research.

Bandagem ajustável do tronco pulmonar: IX: atividade da G6PD do miocárdio de cabras adultas submetido ao treinamento ventricular / Reversible pulmonary trunk banding: IX. G6PD activity of adult goat myocardium submitted to ventricular retraining

OBJETIVO: O aumento da atividade miocárdica da Glicose 6-Fosfato Desidrogenase tem sido demonstrado na insuficiência cardíaca. Este estudo avalia a atividade miocárdica da Glicose 6-Fosfato Desidrogenase no treinamento do ventrículo subpulmonar de cabras adultas. MÉTODOS: Foram utilizadas 18 cabras adultas, divididas em três grupos: convencional (bandagem fixa), sham e intermitente (bandagem ajustável; 12 horas diárias de sobrecarga). A sobrecarga sistólica (70% da pressão sistêmica) foi mantida durante quatro semanas. As avaliações hemodinâmica e ecocardiográfica foram realizadas durante todo o estudo. Depois de cumprido o protocolo, os animais foram mortos para avaliação morfológica e da atividade da Glicose 6-Fosfato Desidrogenase dos ventrículos. RESULTADOS: Apesar de haver sobrecarga sistólica proporcionalmente menor no ventrículo subpulmonar do grupo intermitente (P=0,001), ambos os grupos de estudo apresentaram aumento da massa muscular de magnitude similar. Os grupos intermitente e convencional apresentaram aumento da massa de 55,7% e 36,7% (P<0,05), respectivamente, em comparação ao grupo sham. O conteúdo de água do miocárdio não variou entre os grupos estudados (P=0,27). O ecocardiograma demonstrou maior aumento (37,2%) na espessura do ventrículo subpulmonar do grupo intermitente, em relação aos grupos sham e convencional (P<0,05). Foi observada maior atividade da Glicose 6-Fosfato Desidrogenase na hipertrofia miocárdica do ventrículo subpulmonar do grupo convencional, comparada aos grupos sham e intermitente (P=0,05). CONCLUSÃO: Ambos os grupos de treinamento ventricular desenvolveram hipertrofia ventricular, a despeito do menor tempo de sobrecarga sistólica no grupo intermitente. A maior atividade de Glicose 6-Fosfato Desidrogenase observada no grupo convencional pode refletir um desequilíbrio redox, com maior produção de fosfato de dinucleotídeo de nicotinamida e adenina e glutationa reduzida, um mecanismo importante da fisiopatologia da insuficiência cardíaca.

OBJECTIVE: Increased glucose 6-phosphate dehydrogenase activity has been demonstrated in heart failure. This study sought to assess myocardial glucose 6-phosphate dehydrogenase activity in retraining of the subpulmonary ventricle of adult goats. METHODS: Eighteen adult goats were divided into three groups: traditional (fixed banding), sham, and intermittent (adjustable banding, daily 12-hour systolic overload). Systolic overload (70% of systemic pressure) was maintained during a 4-week period. Right ventricle, pulmonary artery and aortic pressures were measured throughout the study. All animals were submitted to echocardiographic and hemodynamic evaluations throughout the protocol. After the study period, the animals were killed for morphological and glucose 6-phosphate dehydrogenase activity assessment. RESULTS: A 55.7% and 36.7% increase occurred in the intermittent and traditional right ventricle masses, respectively, when compared with the sham group (P<0.05), despite less exposure of intermittent group to systolic overload. No significant changes were observed in myocardial water content in the 3 groups (P=0.27). A 37.2% increase was found in right ventricle wall thickness of intermittent group, compared to sham and traditional groups (P<0.05). Right ventricle glucose 6-phosphate dehydrogenase activity was elevated in the traditional group, when compared to sham and intermittent groups (P=0.05). CONCLUSION: Both study groups have developed similar right ventricle hypertrophy, regardless less systolic overload exposure of intermittent group. Traditional systolic overload for adult subpulmonary ventricle retraining causes upregulation of myocardial glucose 6-phosphate dehydrogenase activity. It may suggest that the undesirable "pathologic systolic overload" is influenced by activation of penthose pathway and cytosolic Nicotinamide adenine dinucleotide phosphate availability. This altered energy substrate metabolism can elevate levels of free radicals by Nicotinamide adenine dinucleotide phosphate oxidase, an important mechanism in the pathophysiology of heart failure.

Reversible pulmonary trunk banding: IX. G6PD activity of adult goat myocardium submitted to ventricular retraining.

OBJECTIVE: Increased glucose 6-phosphate dehydrogenase activity has been demonstrated in heart failure. This study sought to assess myocardial glucose 6-phosphate dehydrogenase activity in retraining of the subpulmonary ventricle of adult goats. METHODS: Eighteen adult goats were divided into three groups: traditional (fixed banding), sham, and intermittent (adjustable banding, daily 12-hour systolic overload). Systolic overload (70% of systemic pressure) was maintained during a 4-week period. Right ventricle, pulmonary artery and aortic pressures were measured throughout the study. All animals were submitted to echocardiographic and hemodynamic evaluations throughout the protocol. After the study period, the animals were killed for morphological and glucose 6-phosphate dehydrogenase activity assessment. RESULTS: A 55.7% and 36.7% increase occurred in the intermittent and traditional right ventricle masses, respectively, when compared with the sham group (P<0.05), despite less exposure of intermittent group to systolic overload. No significant changes were observed in myocardial water content in the 3 groups (P=0.27). A 37.2% increase was found in right ventricle wall thickness of intermittent group, compared to sham and traditional groups (P<0.05). Right ventricle glucose 6-phosphate dehydrogenase activity was elevated in the traditional group, when compared to sham and intermittent groups (P=0.05). CONCLUSION: Both study groups have developed similar right ventricle hypertrophy, regardless less systolic overload exposure of intermittent group. Traditional systolic overload for adult subpulmonary ventricle retraining causes upregulation of myocardial glucose 6-phosphate dehydrogenase activity. It may suggest that the undesirable "pathologic systolic overload" is influenced by activation of penthose pathway and cytosolic Nicotinamide adenine dinucleotide phosphate availability. This altered energy substrate metabolism can elevate levels of free radicals by Nicotinamide adenine dinucleotide phosphate oxidase, an important mechanism in the pathophysiology of heart failure.

Infarto do ventriculo direito / Right ventricle infarction

O infarto do ventrículo direito (VD) não é entidade clínica rara. É observado em 10 a 50% dos pacientes com infarto da parede inferior do ventrículo esquerdo (VE). Estão agrupados nesse amplo espectro diagnóstico os pacientes com disfunção ventricular leve, assintomáticos e aqueles em choque cardiogênico. O reconhecimento do infarto do VD é importante, porque se associa a mais morbi e mortalidade imediatas, além de apresentar prioridade de tratamento específico. O diagnóstico do infarto do VD é baseado em sinais clínicos, eletrocardiográficos, hemodinâmicos e ecográficos. A abordagem adequada do infarto do VD inclui medidas para manter a pré-carga adequada e reduzir a pós-carga do VD, suporte inotrópico, e manutenção do sincronismo átrio-ventricular. A terapia de reperfusão miocárdica com fibrinolítico ou a angioplastia primária deve ser indicada e iniciada precocemente. A maior parte dos pacientes que sobrevivem ao infarto do VD tem resolução completa das alterações hemodinâmicas com o restabelecimento da função do VD no decorrer de semanas a meses, sugerindo que ?atordoamento? do miocárdio direito, em vez de necrose irreversível, ocorre com mais frequência.

Right ventricle infarction (RVI) is not a rare clinical entity. It complicates 10 to 50% of patients with inferior wall myocardial infarctions. Under the term RVI we can find mild, asymptomatic dysfunction of right ventricle and cardiogenic shock as well. Recognition of the syndrome of RVI is important as it is associated with considerable immediate morbidity and mortality and has a well-delineated set of priorities for its management. Diagnosis is based on clinical signs, electrocardiographic findings, hemodynamic measurements and echographic evaluations. The proper management of RVI includes volume loading to maintain adequate right ventricular preload, ionotropic support, reduction of right ventricular afterload and maintenance of atrioventricular synchrony. Early reperfusion with fibrinolytic therapy or direct angioplasty should be initiated at the earliest signs of right ventricular dysfunction. Most patients who survive RVI have complete resolution of hemodynamic abnormalities with restoration of proper right ventricle function over a period of weeks to months, suggesting right ventricular stunning rather than irreversible necrosis has occurred.

Stenosis of reverse great saphenous vein graft in infrainguinal arterial revascularization.

OBJECTIVE: The aim of this study was to evaluate the prevalence of hemodynamically significant infrainguinal bypasses stenosis using reverse great saphenous vein graft. METHODS: From March of 2008 to March of 2009, 56 infrainguinal bypasses were performed with reverse great saphenous vein graft in 56 patients. On the 30th post-operative day, 32 out of 56 patients were submitted to vascular ultrasonography. The prevalence of significant graft stenosis was determined. In addition, the diagnosis of stenosis was related to the clinical and surgical characteristics of the patients. The variables analyzed at the moment of diagnosis were the localization of the graft stenosis, the risk factors associated with stenosis and the association of vascular ultrasonography findings with ankle brachial pressure index (ABI). RESULTS: The overall prevalence of significant graft stenosis was 48.4%. Out of the total number of observed stenosis, 19.4% were considered severe, and 29% mild or moderate. There was no significant association between the presence of significant stenosis and the following variables: gender, diabetes, hypertension, smoking, hipercholesterolemia, graft diameter, site of the distal anastomosis, and graft composition. There was a weak agreement between ABI and vascular ultrasonography in detecting stenosis in general (K = 0.30; CL95% 0.232 - 0.473; p = 0.018). However, there was a substantial agreement in detecting severe stenosis (K = 0.75; CL95% 0.655 - 0.811; p = 0.0001). CONCLUSION: There was a high prevalence of stenosis on the 30th post-operative day, mostly localized in the proximal half of the vein graft. There was no significant association of stenosis with clinical and surgical factors analyzed. ABI and vascular ultrasonography had weak agreement with the diagnosis of stenosis in general and an important agreement for the diagnosis of severe stenosis.

Estenose do enxerto de veia safena magna reversa em revascularização arterial infrainguinal / Stenosis of reverse great saphenous vein graft in infrainguinal arterial revascularization

OBJETIVO: Avaliar a prevalência de estenose hemodinamicamente significativa na revascularização infrainguinal realizada com a veia safena magna reversa. MÉTODOS: No período compreendido entre março de 2008 e março de 2009, foram realizadas 56 revascularizações infrainguinais com a veia safena magna reversa em 56 pacientes, dos quais 32 foram avaliados com ultrassonografia vascular no 30º dia de pós- operatório. Foi analisada a prevalência de estenoses significativas nos enxertos e sua relação com as características clínico-cirúrgicas dos pacientes. Os parâmetros avaliados foram a localização das estenoses ao longo do enxerto, fatores de risco associados e a relação existente entre a ultrassonografia vascular e o índice tornozelo-braço no diagnóstico de estenoses. RESULTADOS: Houve prevalência de 48,4 por cento de estenoses significativas nos enxertos avaliados, com 19,4 por cento de estenoses graves e 29 por cento de estenoses leve a moderada. Não foram encontradas associações significativas entre sexo, diabetes mellitus, hipertensão arterial, hipercolesterolemia, diâmetro do enxerto, localização da anastomose distal, composição do enxerto e a constatação de estenoses significativas. Observou-se fraca correlação entre os métodos no diagnóstico das estenoses em geral (K = 0,30; IC95 por cento 0,232-0,473; p = 0,018), mas razoável concordância no diagnóstico das estenoses graves (K = 0,75; IC95 por cento 0,655-0,811; p = 0,0001). CONCLUSÃO: Este estudo demonstrou elevada prevalência de estenoses no 30º dia do pós-operatório, com localização predominante na metade proximal do enxerto. O índice tornozelo-braço e a ultrassonografia vascular apresentaram concordância, sobretudo no diagnóstico das estenoses graves, mas o índice tornozelo-braço, isoladamente, mostrou-se insuficiente na vigilância dos enxertos de veia safena magna reversa.

OBJECTIVE: The aim of this study was to evaluate the prevalence of hemodynamically significant infrainguinal bypasses stenosis using reverse great saphenous vein graft. METHODS: From March of 2008 to March of 2009, 56 infrainguinal bypasses were performed with reverse great saphenous vein graft in 56 patients. On the 30th post-operative day, 32 out of 56 patients were submitted to vascular ultrasonography. The prevalence of significant graft stenosis was determined. In addition, the diagnosis of stenosis was related to the clinical and surgical characteristics of the patients. The variables analyzed at the moment of diagnosis were the localization of the graft stenosis, the risk factors associated with stenosis and the association of vascular ultrasonography findings with ankle brachial pressure index (ABI). RESULTS: The overall prevalence of significant graft stenosis was 48.4 percent. Out of the total number of observed stenosis, 19.4 percent were considered severe, and 29 percent mild or moderate. There was no significant association between the presence of significant stenosis and the following variables: gender, diabetes, hypertension, smoking, hipercholesterolemia, graft diameter, site of the distal anastomosis, and graft composition. There was a weak agreement between ABI and vascular ultrasonography in detecting stenosis in general (K = 0.30; CL95 percent 0.232 - 0.473; p = 0.018). However, there was a substantial agreement in detecting severe stenosis (K = 0.75; CL95 percent 0.655 - 0.811; p = 0.0001). CONCLUSION: There was a high prevalence of stenosis on the 30th post-operative day, mostly localized in the proximal half of the vein graft. There was no significant association of stenosis with clinical and surgical factors analyzed. ABI and vascular ultrasonography had weak agreement with the diagnosis of stenosis in general and an important agreement for the diagnosis of severe stenosis.

[IV Pulmonary trunk reversible banding: analysis of right ventricle acute hypertrophy in an intermittent loading experimental model]. / Bandagem reversível do tronco pulmonar IV: análise da hipertrofia aguda do ventrículo direito em modelo experimental de sobrecarga intermitente.

OBJECTIVES: Adjustable pulmonary trunk (PT) banding device may induce a more physiologic ventricle retraining for the two-stage Jatene operation. This experimental study evaluates the acute hypertrophy (96 hours) of the right ventricle (RV) submitted to an intermittent pressure overload. METHODS: Five groups of seven young goats were distributed according to RV intermittent systolic overload duration (0, 24, 48, 72 and 96 hours). The zero-hour group served as a control group. Echocardiographic and hemodynamic evaluations were performed daily. After completing the training program for each group, the animals were sacrificed for water content and cardiac masses evaluation. RESULTS: There was a significant increase in RV free wall thickness starting with the 48-hour group (p<0.05). However, a decreased RV ejection fraction, associated with an important RV dilation and a significant increase in the RV volume to mass ratio was observed at 24-hour training period, when compared to 96-hour period (p=0.003), with subsequent recovery throughout the protocol. A 104.7% increase in RV mass was observed in the 96-hour group, as compared to the control group, with no differences in water content between these two groups. The daily mean increase in RV mass during the study period was 21.6% +/- 26.8%. The rate of RV mass acquisition for the overall study period of intermittent systolic overload was 0.084 g/h +/- 0.035 g/h. CONCLUSION: Intermittent PT banding has allowed a significant RV mass acquisition in the 96-hour trained group. No myocardial water content changes were observed in this group, suggesting an increased myocardial protein synthesis.

Partial anomalous return of four pulmonary veins with intact interatrial septum defect. A rare case report.

We report on the rare case of partial anomalous return of four pulmonary veins in the right atrium and superior vena cava with intact interatrial septum in a five-year-old child. There were few symptoms in contrast with the left ventricular output dependent on the flow of the left upper lobe vein and from the lingula. Reduced compliance to the left led to a severe picture of pulmonary venocapillary hypertension in the immediate postoperative period, mitigated by an 8-mm interatrial septal defect. The patient progressed well after the intervention.

Drenagem anômala parcial de quatro veias pulmonares com septo interatrial íntegro: relato de um caso raro / Partial anomalous return of four pulmonary veins with intact interatrial septum defect: a rare case report

É relatado caso raro de drenagem anômala parcial de quatro veias pulmonares no átrio direito e veia cava superior, com septo interatrial íntegro em criança de cinco anos de idade. Havia poucos sintomas, em contraste com débito ventricular esquerdo dependente do fluxo da veia lobar superior esquerda e da língula. Complacência diminuída à esquerda motivou quadro acentuado de hipertensão venocapilar pulmonar no pós-operatório imediato, aliviado por feitura de comunicação interatrial de 8 mm. A evolução posterior foi boa.

We report on the rare case of partial anomalous return of four pulmonary veins in the right atrium and superior vena cava with intact interatrial septum in a five-year-old child. There were few symptoms in contrast with the left ventricular output dependent on the flow of the left upper lobe vein and from the lingula. Reduced compliance to the left led to a severe picture of pulmonary venocapillary hypertension in the immediate postoperative period, mitigated by an 8-mm interatrial septal defect. The patient progressed well after the intervention.

Bandagem reversível do tronco pulmonar IV: análise da hipertrofia aguda do ventrículo direito em modelo experimental de sobrecarga intermitente / IV Pulmonary trunk reversible banding: analysis of right ventricle acute hypertrophy in an intermittent loading experimental model

OBJETIVO: A bandagem ajustável do tronco pulmonar (TP) pode proporcionar treinamento ventricular mais fisiológico para cirurgia de Jatene em dois estágios. Este estudo experimental analisa a hipertrofia aguda (96 horas) do ventrículo direito (VD) submetido à sobrecarga sistólica intermitente. MÉTODOS: Cinco grupos de sete cabritos jovens foram dispostos conforme o tempo de sobrecarga sistólica do VD (0, 24, 48, 72 e 96 horas). O grupo zero hora funcionou como grupo controle. Avaliações ecocardiográficas e hemodinâmicas foram feitas diariamente. Os animais foram sacrificados para avaliação do conteúdo de água e pesagem das massas cardíacas. RESULTADOS: Houve aumento da espessura do VD a partir de 48 horas de treinamento (p<0,05) e rebaixamento da fração de ejeção do VD, com dilatação importante desta câmara nas primeiras 24 horas do protocolo, recuperando-se posteriormente. Houve aumento da relação volume/massa nas primeiras 24 horas do protocolo, em relação ao momento 96 horas (p=0,003). A massa do VD apresentou aumento de 104,7 por cento no grupo 96 horas em relação ao controle. Não houve diferença quanto ao conteúdo de água do VD. A média diária de aumento da massa do VD foi de 21,6 por cento ± 26,8 por cento. A taxa de ganho de massa muscular do VD para todo o período de estudo foi de 0,084 g/h ± 0,035 g/h. CONCLUSÃO: O protocolo de bandagem intermitente do TP permitiu ganho de massa muscular do VD, significativa no grupo de 96 horas de estudo. Esta hipertrofia não foi acompanhada de aumento no conteúdo de água, o que sugere maior síntese protéica nos tecidos cardíacos.

OBJECTIVES: Adjustable pulmonary trunk (PT) banding device may induce a more physiologic ventricle retraining for the two-stage Jatene operation. This experimental study evaluates the acute hypertrophy (96 hours) of the right ventricle (RV) submitted to an intermittent pressure overload. METHODS: Five groups of seven young goats were distributed according to RV intermittent systolic overload duration (0, 24, 48, 72 and 96 hours). The zero-hour group served as a control group. Echocardiographic and hemodynamic evaluations were performed daily. After completing the training program for each group, the animals were sacrificed for water content and cardiac masses evaluation. RESULTS: There was a significant increase in RV free wall thickness starting with the 48-hour group (p<0.05). However, a decreased RV ejection fraction, associated with an important RV dilation and a significant increase in the RV volume to mass ratio was observed at 24-hour training period, when compared to 96-hour period (p=0.003), with subsequent recovery throughout the protocol. A 104.7 percent increase in RV mass was observed in the 96-hour group, as compared to the control group, with no differences in water content between these two groups. The daily mean increase in RV mass during the study period was 21.6 percent ± 26.8 percent. The rate of RV mass acquisition for the overall study period of intermittent systolic overload was 0.084 g/h ± 0.035 g/h. CONCLUSION: Intermittent PT banding has allowed a significant RV mass acquisition in the 96-hour trained group. No myocardial water content changes were observed in this group, suggesting an increased myocardial protein synthesis.