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Resumo Fundamento O modelo de hipertensão arterial pulmonar induzida por monocrotalina (MCT) é um dos mais reproduzidos atualmente, apresentando como limitação a ausência de lesões plexiformes, manifestações típicas da doença grave em humanos. Objetivo Avaliar a gravidade da arteriopatia pulmonar induzida por MCT por meio dos achados anatomopatológicos pulmonares e cardíacos, evolução clínica e sobrevida em 37 dias. Métodos Foram utilizados 50 ratos machos Wistar divididos em quatro grupos, sendo um controle (n = 10). Os três grupos restantes foram submetidos à inoculação de MCT (60 mg/kg i.p.) e ficaram sob o seu efeito por 15 (n = 10), 30 (n = 10) e 37 dias (n = 20). Ao final de cada período, os animais foram sacrificados, obtendo-se tecidos pulmonar e cardíaco para análise anatomopatológica e morfométrica. Empregou-se o teste Kruskal-Wallis, considerando nível de significância de 5%. Resultados Nos pulmões dos animais MCT foram constatadas lesões referentes à arteriopatia pulmonar, incluindo muscularização das arteríolas, hipertrofia da camada média e lesões neointimais concêntricas. Lesões complexas foram observadas nos grupos MCT, descritas como plexiforme e do "tipo" plexiforme (plexiform-like). A hipertrofia do ventrículo direito foi constatada pelo aumento da espessura e diâmetro dos cardiomiócitos e pelo aumento significativo da espessura da parede do ventrículo direito (p<0,0000). Conclusão O modelo foi capaz de gerar arteriopatia pulmonar moderada-grave associada à hipertrofia do ventrículo direito secundária, com sobrevida de 50% em 37 dias. De nosso conhecimento, este estudo foi o primeiro a constatar a presença de lesões vasculares complexas, semelhantes às observadas em pacientes com hipertensão arterial pulmonar grave, em modelo isolado de MCT. (Arq Bras Cardiol. 2020; 115(3):480-490)
Abstract Background The monocrotaline (MCT)-induced pulmonary arterial hypertension model is one of the most reproduced today, presenting as a limitation the absence of plexiform lesions, typical manifestations of the severe disease in humans. Objective To evaluate the severity of MCT-induced pulmonary arteriopathy by pathological findings of lung and heart tissue samples, clinical course and 37-day survival. Methods Fifty male Wistar rats were divided into one of the four groups - control (CG) (n = 10) and three intervention (MCT) groups. The MCT groups received intraperitoneal injection (60 mg/kg) of MCT and remained exposed to the substance for 15 days (G15, n = 10), 30 days (G30, n = 10) and 37 days (G37, n = 20). At the end of each period, the animals were sacrificed, and pulmonary and cardiac tissues were collected for anatomopathological and morphometric analysis. The Kruskal-Wallis test was used, considering a level of significance of 5%. Results In the lungs of MCT animals, lesions related to pulmonary arteriopathy were found, including muscularization of the arterioles, hypertrophy of the middle layer and concentric neointimal lesions. Complex lesions were observed in MCT groups, described as plexiform and plexiform-like lesions. Right ventricular hypertrophy was evidenced by increased thickness and diameter of the cardiomyocytes and a significant increase in the right ventricular wall thickness (p <0.0000). Conclusion The MCT model was able to generate moderate-severe pulmonary arteriopathy associated with secondary right ventricular hypertrophy. The 37-day survival rate was 50%. To our knowledge, this study was the first to note the presence of complex vascular lesions, similar to those observed in patients with severe pulmonary arterial hypertension, in an isolated MCT model. (Arq Bras Cardiol. 2020; 115(3):480-490)
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Humans , Animals , Male , Rats , Pulmonary Arterial Hypertension , Hypertension, Pulmonary/chemically induced , Monocrotaline/toxicity , Rats, Wistar , Hypertrophy, Right Ventricular/chemically inducedABSTRACT
Introduction: Myocardial Infarction is the term used when the myocardium is necrosed due to ischemia. It may be trans mural or subendocardial. Inferior wall infarction has got some special features like the association with Right ventricular infarction and Brady arrhythmias especially sinus bradycardia and heart blocks. Clinically Right Ventricular Myocardial Infarction can be suspected when a patient with Inferior Wall Myocardial Infarction presents with elevated JVP, positive Kussmaul's sign, hypotension, right-sided third or fourth heart sounds, tender hepatomegaly, and oliguria rarely TR and clear chest. Aim of the study: To study the various clinical manifestation of Right Ventricular Myocardial Infarction. To study the Clinical profile, Risk factors, ECG features, Complications and Outcome of Right Ventricular Myocardial Infarction. Materials and methods: This study was mainly conducted to find out the clinical manifestations of right ventricular myocardial infarction and its risk factors, ECG features, complications and outcome of RVMI. All patients admitted to Intensive Coronary Care Unit with ST elevation in V4R were taken for study. Presence of an aneurysm, mitral regurgitation, left ventricular clot or pericardial effusion was noted. Ejection fraction was determined by-Mode and2-D using Simpson’s rule. Results: During the study period 474 cases of acute myocardial infarction were admitted and. Out of 474 cases, 242 were acute inferior wall myocardial infarction. 106 cases showed evidence of right ventricular myocardial infarction in ECG. All the 106 cases were associated with inferior wall myocardial infarction. Angina was present in 73% of patient. Angina was equivalent to 27%. All patients with chest pain were associated with sweating. Nausea, vomiting, and Indigestion were the V. Magesh, Karthikeyan K. A study of clinical manifestations of right ventricular myocardial infarction. IAIM, 2018; 5(1): 121-128. Page 122 common presenting angina equivalents in young. Dyspnea was the predominant symptom in elderly people. Most of the patients with angina equivalents were Diabetes. Conclusion: All cases of Inferior Wall Myocardial Infarction should have Right sided chest leads recorded during ECG examination as more the ST elevation more the severity of Right Ventricular Myocardial Infarction and its complications and mortality rate. If the diagnosis of Right Ventricular Myocardial Infarction is correctly made earlier and thrombolysed the prognosis is usually good even in patients with complications.
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Objectives:The aim of this study was to observe whether transthoracic pulmonary artery denervation (TPADN) could reduce the pulmonary arterial pressure and attenuate pulmonary vascular remodeling in rats with pulmonary arterial hypertension induced by monocrotaline. Methods:Twenty-four healthy male SD rats were randomly divided into control group, sham operation group and operation group (n=8 per group). Rats in sham operation group and operation group received single subcutaneous injection of monocrotaline (MCT, 60 mg/kg). After four weeks, the mean pulmonary arterial pressure (mPAP) and other hemodynamic parameters were measured with the right heart catheter in rats of these two groups. Then, operation group received the surgery of TPADN, which included thoracotomy in left 2-3 rib, exposing pulmonary artery, and removing the near connective tissue of the pulmonary artery trunk. After two weeks of operation, the mPAP and other hemodynamic parameters were measured again by the right heart catheter. The microstructure changes of the heart and pulmonary vessels was observed by immunohistochemistry and immunofluorescence. Meanwhile, RV cardiomyocyte cross-sectional area (CSA) and the right hearthy pertrophy index (RVHI= RV/[LV+S]) were used to evaluate the degree of right ventricular hypertrophy. Results:After four weeks of injection of MCT, the mPAP was significantly higher in the operation group and the sham operation group than in control group (P＜0.01). Two weeks after the surgery of TPADN, the mPAP was significantly reduced in the operation group than compared in the sham group(P＜0.01). Meanwhile, the percentage of medial thickness to outer diameter of the small pulmonary arterioles, right ventricular myocardial cell cross-sectional area and RVHI were also significantly decreased in the operation group compared to sham operation group(all P＜0.01). Conclusions:Our results show that TPADN could reduce the mean pulmonary arterial pressure and attenuate the hypertrophy of medial thickness of small pulmonary arterioles and of right ventricle in PAH rats induced by monocrotaline.
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Objective To investigate correlation of right ventricular hypertrophy and vitamin D , atrial fibrillation and NT-proBNP in patients with pulmonary heart disease.Methods 40 cases of pulmonary heart disease were selected, according to whether the right ventricular hypertrophy or not, and divided into hypertrophy group and non hypertrophy group.Echocardiography, serum 25 hydroxy vitamin D, 24 h dynamic electrocardiogram and NT-proBNP level were detected, and the correlation were detected between the right ventricular hypertrophy and influence factors.ResuIts The right ventricular anterior wall ( RVAW) and right ventricular diastolic diameter ( RVDd) in hypertrophy group were significantly greater than those in non hypertrophy group (P<0.05).The serum 25 hydroxy vitamin D levels in hypertrophy group was lower than that in non hypertrophy group (P<0.05), but there was no significant correlation of right ventricular hypertrophy and 25 hydroxy vitamin D levels(r=-0.189,P=0.424).The thickness of right ventricular anterior wall in atrial fibrillation group was greater than that in non atrial fibrillation group (P<0.05), but there was no significant correlation of right ventricular hypertrophy and atrial fibrillation times(r=0.178,P=0.452).Serum NT-proBNP levels in hypertrophy group was higher than that in non hypertrophy group (P<0.05), but there was no significant correlation of right ventricular hypertrophy and serum NT-proBNP levels(r=-0.105, P=0.660).ConcIusion Patients with right ventricular hypertrophy of pulmonary heart disease who has a lower serum 25 hydroxy vitamin D level and a higher NT-proBNP level.Patients with atrial fibrillation has a thicker RVAW.However, there was no correlation of above influence factors.
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Objective To investigate the safety and effectiveness of percutaneous balloon pulmonary valvuloplasty (PBPV) in the treatment of pulmonary stenosis (PS). Methods The subjects were 52 patients with PS from 2007 to 2012, including 24 male and 28 female. Their age ranged from 1 year old to 56 year old and mean age was 9.2±7.6 years old. Their body weight ranged from 10 kg to 60 kg and mean weight was 17.3±8.9 kg. All patients were assessed with electrocardiogram (ECG), chest X-ray, right heart catheterization and right ventricular angiagraphy before the procedure. Results All 52 patients received PBPV successfully. Comparing the transvalvular pressure gradient before and after the operation, it decreased from 86.3±27.6 mmHg (1 mmHg=0.133 kPa) to13.8±7.7 mmHg, and statistically difference (P<0.01). Among these patients, one patient occurred ventricular fibrillation and Aspen syndrome (hypoxie-ischemic encephalopathy), one patient occurred respiratory and cardiac arrest, 24 patients occurred transient arrhythmia, one patient had hypotension, one patient had bradycardia and one patient showed desaturation. All these symptoms resolved after appropriate treatment during the PBPV. Two patients had hematoma in the puncture point and 2 patients had reactive infundibular stenosis after PBPV. Conclusions Performing the percutaneous balloon pulmonary valvoplasty on the patients with pulmonary stenosis is safe and effective. PBPV causes less pain and can be used as the preferred treatment for pulmonary stenosis.
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This study was aimed to diffuse the lung and promote urination for the observation of cardiopulmonary re-lated index change of cor pulmonale rats to further explore the treatment effect on the pulmonary function, pulmonary arterial hypertension (PAH) and the influence of right heart hypertrophy of rats, in order to further illustrate the ef-fect of diffusing the lung and promoting urination for cor pulmonale. Sixty Wistar rats were randomly divided into the control group, model group and Xiao-Qing-Long decoction (XQLD) group with 20 rats in each group. The AniRes2003 animal lung function analysis system was applied to measure the pulmonary function of rats. And the multi-guide physiological recorder was used in the recording of the pulmonary artery pressure of rats. The conven-tional weighing method was applied to calculate and obtain the change of right heart hypertrophy. The results showed that compared to the control group, symptoms in the model group became severe obviously, which include reduced activity, slow movement and occasional airway sputum sound, and the right heart hypertrophy index of the model group increased obviously (P < 0.01). Compared to the model group, the pulmonary function and pulmonary artery pressure of the XQLD group have obvious difference (P< 0.05). It was concluded that to diffuse the lung and pro-mote urination can effectively improve the pulmonary function, PAH and the right heart hypertrophy index of rats with cor pulmonale (fluid retention). The effect of this method is definite in the treatment of cor pulmonale.
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OBJETIVO: Medir a espessura ventricular direita e esquerda em falecidos com história de hipertensão arterial, submetidos a necropsias clínicas. MÉTODOS: Foram selecionados 90 casos do Serviço de Verificação de Óbitos de Recife -PE, de ambos os sexos, com história de hipertensão arterial essencial, com relação à espessura das paredes cardíacas, além da correlação com outros achados de necropsia e informes clínicos. RESULTADOS: Observouse associação significativa entre a presença de hipertrofia ventricular esquerda (HVE) e direita (HVD), e de cardiopatia hipertensiva grave e HVD. Houve predomínio da HVD e HVE em homens, na faixa etária dos 60-79 anos, com maior prevalência nas etnias parda e negra, e naqueles com estado nutricional adequado ou com sobrepeso e em obesos. CONCLUSÃO: Observou-se que a presença de HVD relaciona-se com HVE, sugerindo que há fatores patogênicos semelhantes envolvidos no desenvolvimento da hipertrofia bilateral. A HVD parece associar-se à doença cardíaca mais grave, podendo, a partir de outros estudos, ser considerada novo fator prognóstico na avaliação dos pacientes hipertensos.
OBJECTIVE: To measure the right and left ventricular thickness in deceased individuals with a history of hypertension submitted to clinical autopsies. METHODS: We selected 90 cases from the Death Verification Service of the city of Recife, state of Pernambuco, Brazil, of both sexes, with a history of essential arterial hypertension related to heart wall thickness, in addition to correlation with autopsy findings and other clinical reports. RESULTS: There was a significant association between the presence of left ventricular hypertrophy (LVH) and right ventricular hypertrophy (RVH) and between severe hypertensive cardiomyopathy and RVH. There was a predominance of RVH and LVH in men aged 60-79 years and a higher prevalence in the Brazilian mulatto and Black ethnic groups and in those with adequate nutritional status or overweight and obese individuals. CONCLUSION: It was observed that the presence of RVH was related to LVH, suggesting that there are similar pathogenic factors involved in the development of bilateral hypertrophy. The RVH seems to be associated with more severe heart disease and may, based on other studies, be considered as a new prognostic factor in the evaluation of hypertensive patients.
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Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Heart Ventricles/pathology , Hypertension/pathology , Hypertrophy, Left Ventricular/pathology , Hypertrophy, Right Ventricular/pathology , Autopsy , Cross-Sectional Studies , Hypertension/complications , Hypertrophy, Left Ventricular/etiology , Hypertrophy, Right Ventricular/etiologyABSTRACT
Pacientes portadores de transposição das grandes artérias submetidos previamente. Correção cirúrgica no plano atrial ou transposição corrigida das grandes artérias frequentemente evoluem com disfunção do ventrículo direito morfológico. Para estes casos, tem sido proposta a correção anatômica, chamada cirurgia de Double Switch ou dupla inversão, invariavelmente realizada na adolescência ou na idade adulta. Com isso, grande parte destes pacientes necessita preparar o ventrículo esquerdo, através da bandagem do tronco pulmonar. Várias são as dificuldades no preparo do miocárdio adulto e resultados desapontadores são relatados nestes indivíduos. O objetivo deste trabalho foi promover e analisar o processo de adaptação do ventrículo direito em modelo animal adulto, comparando o método de bandagem fixa, utilizado tradicionalmente na prática clínica, com um novo método de bandagem intermitente, por um período de quatro semanas. Foram utilizadas 18 cabras adultas, divididas Em três grupos: Chama (n = 6, peso = 26,42. 2,63 Kg, bandagem frouxa, sem sobrecarga sistólica), Fixo (n = 6, peso = 26,33 . 2,32 kg, bandagem convencional com sobrecarga sistólica contínua do ventrículo direito), Intermitente (n = 6, peso = 25,17. 2,48 kg, bandagem com dispositivo ajustável e 12 horas diárias de sobrecarga sistólica do ventrículo direito). No grupo fixo, os animais foram submetidos bandagem do tronco pulmonar com fita umbilical, tentando alcançar uma relação pressórica entre ventrículo direito e aorta de 0,7 no momento da cirurgia. Nos animais do grupo Intermitente, a sobrecarga sistólica foi promovida por um dispositivo ajustável calibrado percutaneamente. A mesma relação pressórica foi almejada diariamente através da insuflação do dispositivo por 12 horas, alternada com 12 horas de desinsuflação do dispositivo. Aferições hemodinâmicas foram feitas três vezes por semana no grupo Intermitente e duas vezes por semana nos grupos Fixo e Sham...
One of the late complications of patients with simple or congenitally corrected transposition of the great arteries includes right (systemic) ventricular failure. The policy of anatomic repair (double switch operation) has often been proposed for adolescents and adults. However, a period of reconditioning the left ventricle through pulmonary artery banding is often required. Although it appears to be capable of providing adequate left ventricular training when done at an early age, it is not always suitable for mature myocardium, with disappointing results in older patients. This study sought to assess two different methods of promoting right ventricles hypertrophy in adult animals for a four-week period, by means of fixed and intermittent adjustable pulmonary artery banding system. Eighteen healthy adult goats were distributed into three groups: Sham (n = 6, weight = 26.42 kg 2.63 kg, loose pulmonary artery banding, no systolic pressure overload), Fixed (n = 6, weight = 26.33 kg 2.32 kg, continuous systolic overload with fixed pulmonary artery band) and Intermittent (n = 6, weight = 25.17 kg 2.48 kg, daily 12-hour systolic overload with adjustable pulmonary artery band). Sham group animals received a loose pulmonary band, while in the Fixed group, an umbilical tape was used to band the pulmonary trunk, adjusted during the implantation to achieve a 0.7 right ventricle / aorta pressure ratio. In the Intermittent group, an adjustable pulmonary artery banding device was implanted on the pulmonary trunk and adjusted according to the volume injected percutaneously. The banding system was inflated daily until the 0.7 pressure ratio was achieved. Systolic overload was maintained for 12 hours, alternated with a 12-hour resting period. All animals were submitted to echocardiographic studies on a weekly basis, while hemodynamic evaluations were performed three times a week in the Intermittent group and twice a week in the Fixed and Sham groups...
Subject(s)
Animals , Guinea Pigs , Goats , Heart Ventricles , Hypertrophy, Left Ventricular , Hypertrophy/physiopathology , Pulmonary Artery , Cardiac Surgical Procedures/methods , Transposition of Great Vessels/surgeryABSTRACT
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.
Subject(s)
Animals , Hypertrophy, Right Ventricular/physiopathology , Models, Cardiovascular , Transposition of Great Vessels/surgery , Disease Models, Animal , Goats , Hemodynamics , Heart Ventricles/physiopathology , Ligation , Organ Size , Systole/physiology , Ventricular Function, Right/physiologyABSTRACT
INTRODUÇÃO: Para os pacientes portadores de transposição das grandes artérias que perderam a chance da cirurgia de Jatene nas primeiras semanas de vida, indica-se realizar o preparo ventricular através da bandagem do tronco pulmonar (BTP), objetivando causar aumento na massa miocárdica. Entretanto, com o tempo, a câmara hipertrofiada pode apresentar disfunção contrátil; portanto, é importante conhecer a qualidade do tecido preparado, uma vez que já se sabe que tanto os miocardiócitos (MCD) quanto as células do interstício e vasos (I/V) são capazes de proliferar após o período neonatal. Baseando-se no condicionamento físico de atletas e considerando-se que os músculos cardíaco e esquelético são ambos estriados, postula-se a hipótese de que o tipo de preparo ventricular possa influenciar nas características do miocárdio treinado. OBJETIVOS: Identificar o tipo de mecanismo adaptativo (hipertrofia/hiperplasia) envolvido no preparo rápido do ventrículo pulmonar submetido à sobrecarga de pressão por meio de BTP, através da análise dos MCD e células do I/V, verificando se existem diferenças em relação ao tipo de treinamento (contínuo x intermitente) em comparação com os controles. MÉTODOS: Foram estudados experimentalmente 21 cabritos após o período neonatal, divididos em três grupos (C = grupo controle, n = 7, sem procedimento cirúrgico; EC = grupo de estimulação contínua, n = 7, com bandagem progressiva e permanente do tronco pulmonar durante 96 horas; EI = grupo de estimulação intermitente, n = 7, com bandagem progressiva, 12 horas ao dia, totalizando 48 horas). Todos foram submetidos a estudo ecocardiográfico basal e aqueles dos grupos EC e EI a ecocardiogramas diários para verificar a aquisição de massa muscular do ventrículo direito (VD). Após o estudo, os animais foram sacrificados, os corações retirados e cortes histológicos do VD, ventrículo esquerdo (VE) e septo interventricular (S) fixados em formalina e processados para análise...
INTRODUCTION: Rapid ventricular conditioning induced by pulmonary artery banding (PAB) has been indicated to those patients with transposition of the great arteries (TGA) who have lost the chance for arterial switch operation ? Jatene?s procedure ? aiming at induce myocardial mass increase. However, with time, hypertrophied chamber may exhibit contractile dysfunction, so that, it is important to assess quality of the prepared tissue, once it is of knowledge that both cardiomyocytes (CMC) and interstitial/vessel (I/V) cells are capable of proliferating after neonatal period. Based on fitness of athletes and considering that cardiac and skeletal muscles are both striated, there is the hypothesis that the type of ventricular prepare may influence the characteristics of the training myocardium. OBJECTIVES: Through CMC and I/V cells analysis, identifies the type of adaptive mechanism (hypertrophy/ hyperplasia) involved in rapid prepare of subpulmonary ventricle submitted to pressure overload by PAB, and verifies if there are differences in relation to the kind of training (continuous x intermittent), comparing them to the controls. METHODS: Twenty-one goats, beyond neonatal period, were experimentally studied. They were divided in three groups: C (control group, n = 7, with no surgical procedure); CS (continuous stimulation group, n = 7, with progressive and permanent PAB, during 96 hours); IS (intermittent stimulation group, n = 7, with progressive PAB, 12 hours/day, totalizing 48 hours). All the animals were submitted to basal echocardiograms and those from CS and IS groups to diary echocardiograms to verify right ventricular (RV) muscular mass acquisition. After the study, goats were killed, hearts excised and histological sections from RV, left ventricle (LV) and ventricular septum (VS) were formalin fixed and histologically processed. Collagen area fraction (through Picro-sirius red staining), CMC and respective nuclei diameter, and number of CMC and I/V...
Subject(s)
Animals , Guinea Pigs , Heart Defects, Congenital , Hypertrophy, Right Ventricular , Cell Proliferation , Thoracic Surgery , Transposition of Great VesselsABSTRACT
O preparo do ventrículo sub-pulmonar através da bandagem do tronco pulmonar (TP) pode ser aplicado nos pacientes portadores de transposição das grandes artérias (TGA) que perderam a chance da cirurgia no período neonatal ou naqueles já submetidos à correção no plano atrial (Senning ou Mustard) e ainda nos portadores de transposição corrigida das grandes artérias (TCGA), que evoluíram com disfunção do ventrículo direito (sistêmico). Nesses casos, a bandagem do TP poderá induzir a hipertrofia do ventrículo sub-pulmonar (ventrículo esquerdo) na TGA, habilitando-o para o manuseio da circulação sistêmica após a cirurgia de Jatene. Entretanto, durante o preparo do ventrículo esquerdo (VE), observa-se elevada morbimortalidade, provavelmente relacionada a uma sobrecarga aguda de pressão, não tolerada pelo ventrículo. Isto se deve à dificuldade em ajustar o diâmetro da bandagem do TP, realizada em condições não fisiológicas, com o paciente anestesiado e com o tórax aberto. O objetivo deste trabalho foi o de comparar a eficiência de dois protocolos experimentais de sobrecarga pressórica contínua e intermitente do ventrículo direito (VD) para induzir a hipertrofia rápida do ventrículo subpulmonar. Foram utilizados 21 cabritos jovens (30 a 60 dias de idade), divididos em três grupos: controle (n = 7, peso = 7,5 ± 1,9 kg), contínuo (n = 7, peso = 9,3 ± 1,4 kg, sobrecarga sistólica contínua do VD), intermitente (n = 7, peso = 8,1 ± 0,8 kg, 12 horas/dia de sobrecarga sistólica do VD). A sobrecarga sistólica foi obtida através de um manguito hidráulico de silicone implantado no tronco pulmonar. O dispositivo foi insuflado percutaneamente, através de um botão auto selante de silicone, com o objetivo de se atingir uma relação de pressões entre VD e VE de 70%. Avaliações ecocardiográficas e hemodinâmicas foram feitas diariamente. A sobrecarga sistólica do VD foi mantida por 96 horas no grupo contínuo e por quatro períodos de 12 horas, alternados com 12 horas de descanso...
Preparation of the subpulmonary ventricle with pulmonary trunk (PT) banding may be applied not only in patients with transposition of the great arteries (TGA) beyond the neonatal period, but also in those who present with systemic ventricular failure in corrected TGA or after failed atrial baffle operations. PT banding can induce subpulmonary ventricle hypertrophy that must be able to assume the increased work load and support the systemic circulation. However, subpulmonary ventricle training carries a high morbidity and mortality rates, probably related to acute pressure overload, not tolerated by the ventricle. Adjustment of PT banding under non-physiological conditions is hard to achieve. We sought to assess two different programs of systolic overload (continuous and intermittent) on the pulmonary ventricle (RV) of young goats with the aim of inducing rapid ventricular hypertrophy. Twenty one healthy 60-days-old goats were divided in three groups: control (n = 7, wt = 7.5±1.9 kg, no surgical procedure), continuous stimulation (n = 7, wt = 9.3±1.4 kg, continuous RV systolic overload), and intermittent stimulation (n = 7, wt = 8.1 ± 0.8 kg, 12 hours a day RV systolic overload). Pressure load was achieved by an adjustable PT banding device. The device was implanted around the PT and inflated percutaneously so that a 0.7 RV/LV pressure ratio was achieved. Echocardiographic and hemodynamic evaluations were performed every day. Systolic overload was maintained for 96 hours in the continuous group, while the intermittent group had four 12-hour periods of systolic overload, alternated with a resting period of 12 hours. The animals were then killed for water content evaluation. The inttermitent group achieved a significant increase (p<0,05) of RV mass (1,7 g/kg ± 0,5 g/kg) and septum (1,4 g/kg ± 0,3 g/kg), as compared to the ones from control group (RV: 0,9 g/kg ± 0,2 g/kg; septum: 1,0 g/kg ± 0,2 g/kg), while the continuous group showed only an RV mass increase...