Myocardial Dysfunction after Severe Food Restriction Is Linked to Changes in the Calcium-Handling Properties in Rats.

Severe food restriction (FR) impairs cardiac performance, although the causative mechanisms remain elusive. Since proteins associated with calcium handling may contribute to cardiac dysfunction, this study aimed to evaluate whether severe FR results in alterations in the expression and activity of Ca2+-handling proteins that contribute to impaired myocardial performance. Male 60-day-old Wistar-Kyoto rats were fed a control or restricted diet (50% reduction in the food consumed by the control group) for 90 days. Body weight, body fat pads, adiposity index, as well as the weights of the soleus muscle and lung, were obtained. Cardiac remodeling was assessed by morphological measures. The myocardial contractile performance was analyzed in isolated papillary muscles during the administration of extracellular Ca2+ and in the absence or presence of a sarcoplasmic reticulum Ca2+-ATPase (SERCA2a) specific blocker. The expression of Ca2+-handling regulatory proteins was analyzed via Western Blot. Severe FR resulted in a 50% decrease in body weight and adiposity measures. Cardiac morphometry was substantially altered, as heart weights were nearly twofold lower in FR rats. Papillary muscles isolated from FR hearts displayed mechanical dysfunction, including decreased developed tension and reduced contractility and relaxation. The administration of a SERCA2a blocker led to further decrements in contractile function in FR hearts, suggesting impaired SERCA2a activity. Moreover, the FR rats presented a lower expression of L-type Ca2+ channels. Therefore, myocardial dysfunction induced by severe food restriction is associated with changes in the calcium-handling properties in rats.

Testosterone deficiency reduces the effects of late cardiac remodeling after acute myocardial infarction in rats.

Testosterone is associated with an increased risk of coronary heart disease. This study evaluated cardiac remodeling 60 days after myocardial infarction (MI) in rats with testosterone deficiency. One week after castration, the animals underwent myocardial infarction. Rats were divided into four groups: orchidectomized (OCT); orchidectomized and infarcted (OCT+MI), MI and control (Sham). The myocyte cross-sectional area and the papillary muscle contractility were evaluated 8 weeks after MI. The coronary bed was perfused with Biodur E20 resin to evaluate the neovascularization after MI. Data were expressed as mean ± SEM followed by ANOVA. Castration reduced myocyte hypertrophy when compared to Sham and myocardial infarction alone as well as preserved the contraction force and activation time after myocardial infarction. After beta-adrenergic stimulation, activation and relaxation kinetics were less impaired in the OCT+MI group than in the MI group. Contraction force was preserved in the OCT+MI group after beta-adrenergic stimulation. Multiple scanning electronic microscope images were obtained to characterize changes in the coronary arteries. Capillary density index was increased in the MI and OCT+MI groups compared with control. The MI and OCT+MI groups were characterized by irregular vessel arrangements with distorted shape, abrupt changes in vessel direction, as well as abrupt changes in diameter after bifurcations when compared to Sham and OCT. The results indicated that testosterone deficiency attenuates adverse cardiac remodeling after MI. Novel findings in this study were that testosterone deficiency in rats, induced by castration, changes the later remodeling after MI, when compared with non castrated rats. The absence of this androgenous hormone seems to be benefic against pathological hypertrophy.

Fasting/Refeeding Cycles Prevent Myocardial Dysfunction and Morphology Damage in the Spontaneously Hypertensive Rats / Ciclos de Jejum/Realimentação Previnem Disfunção Miocárdica e Danos Morfológicos em Ratos Espontaneamente Hipertensos

Abstract Background: Caloric restriction is known to impair the cardiac function and morphology in hypertrophied hearts of spontaneously hypertensive rats (SHR); however, the influence of fasting/refeeding (RF) is unknown. Objective: To investigate the fasting/refeeding approach on myocardial remodeling and function. In addition, the current study was designed to bring information regarding the mechanisms underlying the participation of Ca2+ handling and b-adrenergic system. Methods: Sixty-day-old male SHR rats were submitted to food ad libitum (C), 50% food restriction (R50) or RF cycles for 90 days. Cardiac remodeling was assessed by ultrastructure analysis and isolated papillary muscle function. The level of significance considered was 5% (a = 0.05). Results: The RF rats presented lower cardiac atrophy than R50 in relation to C rats. The C rats increased weight gain, R50 maintained their initial body weight and RF rats increased and decreased weight during RF. The RF did not cause functional impairment because the isotonic and isometric parameters showed similar behavior to those of C. The isotonic and isometric cardiac parameters were significantly elevated in RF rats compared to R50 rats. In addition, the R50 rats had cardiac damage in relation to C for isotonic and isometric variables. While the R50 rats showed focal changes in many muscle fibers, the RF rats displayed mild alterations, such as loss or disorganization of myofibrils. Conclusion: Fasting/refeeding promotes cardiac beneficial effects and attenuates myocardial injury caused by caloric restriction in SHR rats, contributing to reduce the cardiovascular risk profile and morphological injuries. Furthermore, RF promotes mild improvement in Ca2+ handling and b-adrenergic system.

Resumo Fundamento: A restrição calórica compromete a função e a morfologia cardíacas em corações hipertrofiados de ratos espontaneamente hipertensos (SHR). No entanto, a influência de ciclo de jejum/Realimentação é desconhecida. Objetivo: Investigar o efeito de ciclos de jejum/realimentação sobre a remodelação e função miocárdica. Além disso, o presente estudo foi desenhado para avaliar os mecanismos subjacentes à participação do trânsito de cálcio (Ca+2) e sistema beta-adrenérgico. Métodos: Neste estudo, SHR machos de 60 dias de idade foram submetidos a alimento ad libitum (grupo C), 50% de restrição alimentar (grupo R50) ou ciclos de RF (grupo RF) por 90 dias. A remodelação cardíaca foi avaliada por meio da análise ultraestrutural e função do músculo papilar isolado. Adotou-se o nível de significância de 5% (a = 0,05). Resultados: Os ratos do grupo RF apresentaram menor atrofia cardíaca do que os do grupo R50 em relação aos do grupo C. Os ratos do grupo C aumentaram peso corporal, os ratos do grupo R50 mantiveram seu peso corporal inicial e os ratos do grupo RF aumentaram e reduziram seu peso durante o ciclo RF. O ciclo RF não causou comprometimento funcional, pois os parâmetros isotônicos e isométricos apresentaram comportamento similar aos dos ratos do grupo C. Os parâmetros cardíacos isotônicos e isométricos mostraram-se significativamente elevados nos ratos do grupo RF em comparação aos dos ratos do grupo R50. Além disso, os ratos do grupo R50 apresentaram dano cardíaco em comparação aos ratos do grupo C quanto às variáveis isotônicas e isométricas. Os ratos do grupo R50 apresentaram alterações focais em muitas fibras musculares, enquanto os ratos do grupo RF apresentaram leves alterações, como perda ou desorganização de miofibrilas. Conclusão: Ciclos de Jejum/Realimentação promovem efeitos benéficos cardíacos e atenuam o dano miocárdico causado por restrição calórica em SHR, contribuindo para reduzir o risco cardiovascular e os danos morfológicos. Além disso, o ciclo de jejum/realimentação promove leve melhora do trânsito do Ca2+ e do sistema beta-adrenérgico.

Fasting/Refeeding Cycles Prevent Myocardial Dysfunction and Morphology Damage in the Spontaneously Hypertensive Rats.

BACKGROUND: Caloric restriction is known to impair the cardiac function and morphology in hypertrophied hearts of spontaneously hypertensive rats (SHR); however, the influence of fasting/refeeding (RF) is unknown. OBJECTIVE: To investigate the fasting/refeeding approach on myocardial remodeling and function. In addition, the current study was designed to bring information regarding the mechanisms underlying the participation of Ca2+ handling and b-adrenergic system. METHODS: Sixty-day-old male SHR rats were submitted to food ad libitum (C), 50% food restriction (R50) or RF cycles for 90 days. Cardiac remodeling was assessed by ultrastructure analysis and isolated papillary muscle function. The level of significance considered was 5% (a = 0.05). RESULTS: The RF rats presented lower cardiac atrophy than R50 in relation to C rats. The C rats increased weight gain, R50 maintained their initial body weight and RF rats increased and decreased weight during RF. The RF did not cause functional impairment because the isotonic and isometric parameters showed similar behavior to those of C. The isotonic and isometric cardiac parameters were significantly elevated in RF rats compared to R50 rats. In addition, the R50 rats had cardiac damage in relation to C for isotonic and isometric variables. While the R50 rats showed focal changes in many muscle fibers, the RF rats displayed mild alterations, such as loss or disorganization of myofibrils. CONCLUSION: Fasting/refeeding promotes cardiac beneficial effects and attenuates myocardial injury caused by caloric restriction in SHR rats, contributing to reduce the cardiovascular risk profile and morphological injuries. Furthermore, RF promotes mild improvement in Ca2+ handling and b-adrenergic system.

[Papillary fibroelastoma: retrospective analysis. Clinical presentation and surgical results]. / Fibroelastoma papilar cardíaco: estudio retrospectivo. Presentación clínica y resultados quirúrgicos.

Papillary ibroelastomas are small benign intracardiac tumors known for their embolic potential. Since the introduction of echocardiography with improved resolution and transesophageal imaging techniques, they are being increasingly detected in clinical practice. In recent series, papillary fibroelastoma is considered the most frequent benign tumor of the heart. Our objective was to analyze characteristics and midterm surgical outcome of histologically-confirmed cases of papillary fibroelastoma. We conducted a retrospective study on patients with cardiac tumors submitted to surgical excision between June 1992 and February 2017. Out of 108 patients, 18 had papillary fibroelastomas. Their mean age was 58 years (22-77); 10 were men. The most frequent localizations were the aortic valve (7) and the mitral valve (5). None had significant valvular dysfunction. By transesophageal echocardiography, the tumor size (larger diameter) was 13.33 ± 5.55 mm (6.6-28.0). Two patients, both with tumor in the aortic valve, had suffered a stroke; other two had dyspnoea and atrial flutter, respectively. The remaining 14 patients were asymptomatic and their tumors were incidental findings. In 15 patients the valve was preserved. There was neither surgical mortality nor recurrence after 2.6 years of follow-up. In conclusion, most papillary fibroelastomas can be surgically removed with valve preservation and favorable clinical outcome. However, until the results of randomized trials support the decision, an aggressive surgical approach in asymptomatic patients needs to be defined in the context of surgical expertise.

Fibroelastoma papilar cardíaco: estudio retrospectivo: Presentación clínica y resultados quirúrgicos / Fibroelastoma papilar cardíaco: estudio retrospectivo: Presentación clínica y resultados quirúrgicos

Los fibroelastomas papilares cardíacos son pequeños tumores benignos con potencial embolígeno. Con la incorporación de la ecocardiografía y la mejoría en la resolución de las imágenes, el diagnóstico clínico es cada vez más frecuente, y en series recientes su frecuencia supera a la del mixoma cardíaco. Nuestro objetivo fue analizar las características de una serie de casos de fibroelastoma papilar cardíaco con confirmación histológica operados en nuestro hospital. Analizamos retrospectivamente los tumores cardíacos y las características clínicas de los pacientes operados desde junio de 1992 a febrero de 2017. De 108 operados, 18 presentaron fibroelastoma papilar. La edad media del grupo con fibroelastoma papilar fue 58 años (22-77); 10 eran varones. Las localizaciones más frecuentes fueron la válvula aórtica (7) y la válvula mitral (5). Ninguno presentó disfunción valvular significativa. Por ecografía transesofágica, el tamaño (diámetro mayor) fue 13.33 ± 5.55 mm (6.6-28.0). Cuatro pacientes eran sintomáticos; uno presentaba disnea, otro aleteo auricular, dos con fibroelastoma en válvula aórtica habían sufrido un accidente cerebrovascular. Los restantes, asintomáticos, fueron intervenidos preventivamente. En 15 pacientes el tumor se extirpó sin necesidad de reemplazo valvular. No hubo mortalidad quirúrgica ni recidiva tumoral en el seguimiento de 2.6 años. Se concluye que los fibroelastomas papilares cardíacos pueden ser extirpados con buenos resultados a mediano plazo y, en su mayoría, con preservación valvular. Sin embargo, no existen aún estudios aleatorizados que avalen la escisión quirúrgica en pacientes asintomáticos. Por el momento, esta última depende de la experiencia del grupo quirúrgico tratante.

Papillary ibroelastomas are small benign intracardiac tumors known for their embolic potential. Since the introduction of echocardiography with improved resolution and transesophageal imaging techniques, they are being increasingly detected in clinical practice. In recent series, papillary fibroelastoma is considered the most frequent benign tumor of the heart. Our objective was to analyze characteristics and midterm surgical outcome of histologically-confirmed cases of papillary fibroelastoma. We conducted a retrospective study on patients with cardiac tumors submitted to surgical excision between June 1992 and February 2017. Out of 108 patients, 18 had papillary fibroelastomas. Their mean age was 58 years (22-77); 10 were men. The most frequent localizations were the aortic valve (7) and the mitral valve (5). None had significant valvular dysfunction. By transesophageal echocardiography, the tumor size (larger diameter) was 13.33 ± 5.55 mm (6.6-28.0). Two patients, both with tumor in the aortic valve, had suffered a stroke; other two had dyspnoea and atrial flutter, respectively. The remaining 14 patients were asymptomatic and their tumors were incidental findings. In 15 patients the valve was preserved. There was neither surgical mortality nor recurrence after 2.6 years of follow-up. In conclusion, most papillary fibroelastomas can be surgically removed with valve preservation and favorable clinical outcome. However, until the results of randomized trials support the decision, an aggressive surgical approach in asymptomatic patients needs to be defined in the context of surgical expertise.

Cardiac, Metabolic and Molecular Profiles of Sedentary Rats in the Initial Moment of Obesity / Perfis Cardíaco, Metabólico e Molecular de Ratos Sedentários no Momento Inicial da Obesidade

Abstract Background: Different types of high-fat and/or high-energy diets have been used to induce obesity in rodents. However, few studies have reported on the effects observed at the initial stage of obesity induced by high-fat feeding on cardiac functional and structural remodelling. Objective: To characterize the initial moment of obesity and investigate both metabolic and cardiac parameters. In addition, the role of Ca2+ handling in short-term exposure to obesity was verified. Methods: Thirty-day-old male Wistar rats were randomized into two groups (n = 19 each): control (C; standard diet) and high-fat diet (HF, unsaturated high-fat diet). The initial moment of obesity was defined by weekly measurement of body weight (BW) complemented by adiposity index (AI). Cardiac remodelling was assessed by morphological, histological, echocardiographic and papillary muscle analysis. Ca2+ handling proteins were determined by Western Blot. Results: The initial moment of obesity occurred at the 3rd week. Compared with C rats, the HF rats had higher final BW (4%), body fat (20%), AI (14.5%), insulin levels (39.7%), leptin (62.4%) and low-density lipoprotein cholesterol (15.5%) but did not exhibit alterations in systolic blood pressure. Echocardiographic evaluation did not show alterations in cardiac parameters. In the HF group, muscles were observed to increase their +dT/dt (C: 52.6 ± 9.0 g/mm2/s and HF: 68.0 ± 17.0 g/mm2/s; p < 0.05). In addition, there was no changes in the cardiac expression of Ca2+ handling proteins. Conclusion: The initial moment of obesity promotes alterations to hormonal and lipid profiles without cardiac damage or changes in Ca2+ handling.

Resumo Fundamentos: Diferentes tipos de dietas hiperlipídicas e/ou hipercalóricas têm sido usados para induzir obesidade em roedores. No entanto, poucos estudos relataram os efeitos da obesidade induzida por dieta hiperlipídica em sua fase inicial sobre a remodelação cardíaca funcional e estrutural. Objetivo: Caracterizar o momento inicial da obesidade e investigar parâmetros metabólicos e cardíacos. Além disso, analisar o papel do trânsito de Ca+2 em curtos períodos de exposição à obesidade. Métodos: Ratos Wistar com idade de 30 dias foram distribuídos aleatoriamente em dois grupos (n = 19 em cada grupo): controle (C, dieta padrão) e dieta hiperlipídica (HL, dieta rica em gordura insaturada). O momento inicial da obesidade foi definido por medidas semanais do peso corporal, complementadas pelo índice de adiposidade (IA). A remodelação cardíaca foi avaliada por análise morfológica, histológica, ecocardiográfica e funcional dos músculos papilares. Proteínas envolvidas no trânsito de Ca2+ foram determinadas por Western Blot. Resultados: O momento inicial da obesidade ocorreu na terceira semana. Em comparação aos ratos C, os animais HL apresentaram maior peso corporal final (4%), gordura corporal (20%), IA (14,5%), níveis de insulina (39,7%), leptina (62,4%) e lipoproteína de baixa densidade (15,5%), mas não apresentaram alterações na pressão sistólica. A avaliação ecocardiográfica não mostrou alterações nos parâmetros cardíacos. No grupo HL, observou-se um aumento no +dT/dt (C: 52,6 ± 9,0 g/mm2/s e HL: 68,0 ± 17,0 g/mm2/s; p < 0,05) muscular. Além disso, não houve alterações na expressão cardíaca de proteínas envolvidas no trânsito de Ca2+. Conclusão: O momento inicial da obesidade promove alterações nos perfis hormonais e lipídicos sem causar danos cardíacos ou mudanças no trânsito de Ca2+.

Cardiac, Metabolic and Molecular Profiles of Sedentary Rats in the Initial Moment of Obesity.

BACKGROUND: Different types of high-fat and/or high-energy diets have been used to induce obesity in rodents. However, few studies have reported on the effects observed at the initial stage of obesity induced by high-fat feeding on cardiac functional and structural remodelling. OBJECTIVE: To characterize the initial moment of obesity and investigate both metabolic and cardiac parameters. In addition, the role of Ca2+ handling in short-term exposure to obesity was verified. METHODS: Thirty-day-old male Wistar rats were randomized into two groups (n = 19 each): control (C; standard diet) and high-fat diet (HF, unsaturated high-fat diet). The initial moment of obesity was defined by weekly measurement of body weight (BW) complemented by adiposity index (AI). Cardiac remodelling was assessed by morphological, histological, echocardiographic and papillary muscle analysis. Ca2+ handling proteins were determined by Western Blot. RESULTS: The initial moment of obesity occurred at the 3rd week. Compared with C rats, the HF rats had higher final BW (4%), body fat (20%), AI (14.5%), insulin levels (39.7%), leptin (62.4%) and low-density lipoprotein cholesterol (15.5%) but did not exhibit alterations in systolic blood pressure. Echocardiographic evaluation did not show alterations in cardiac parameters. In the HF group, muscles were observed to increase their +dT/dt (C: 52.6 ± 9.0 g/mm2/s and HF: 68.0 ± 17.0 g/mm2/s; p < 0.05). In addition, there was no changes in the cardiac expression of Ca2+ handling proteins. CONCLUSION: The initial moment of obesity promotes alterations to hormonal and lipid profiles without cardiac damage or changes in Ca2+ handling.

Saturated high-fat diet-induced obesity increases adenylate cyclase of myocardial ß-adrenergic system and does not compromise cardiac function.

Obesity is a worldwide pandemic associated with high incidence of cardiovascular disease. The mechanisms by which the obesity leads cardiac dysfunction are not fully elucidated and few studies have evaluated the relationship between obesity and proteins involved in myocardial ß-adrenergic (ßA) system. The purpose of this study was to evaluate the cardiac function and ßA pathway components in myocardium of obese rats. Male Wistar rats were distributed into two groups: control (n = 17; standard diet) and obese (n = 17; saturated high-fat diet) fed for 33 weeks. Nutritional profile and comorbidities were assessed. Cardiac structure and function was evaluated by macroscopic postmortem, echocardiographic and isolated papillary muscle analyzes. Myocardial protein expression of ß1- and ß2-adrenergic receptors, Gαs protein, adenylate cyclase (AC) and protein kinase A (PKA) was performed by Western blot. Cardiac cyclic adenosine monophosphate (cAMP) levels and PKA activity were assessed by ELISA Obese rats showed increased adiposity index (P < 0.001) and several comorbidities as hypertension, glucose intolerance, insulin resistance, and dyslipidemia compared with control rats. Echocardiographic assessment revealed increased left atrium diameter (C: 4.98 ± 0.38 vs. Ob: 5.47 ± 0.53, P = 0.024) and posterior wall shortening velocity (C: 37.1 ± 3.6 vs. Ob: 41.8 ± 3.8, P = 0.007) in obese group. Papillary muscle evaluation indicated that baseline data and myocardial responsiveness to isoproterenol stimulation were similar between the groups. Protein expression of myocardial AC was higher in obese group than in the control (C: 1.00 ± 0.21 vs. Ob: 1.25 ± 0.10, P = 0.025), whereas the other components were unchanged. These results suggest that saturated high-fat diet-induced obesity was not effective in triggering cardiac dysfunction and impair the beta-adrenergic signaling.

Ruptura do músculo papilar anterolateral em paciente com endocardite infecciosa e doença valvar mitral reumática: rlato de caso / Anterolateral papillary muscle rupture in association with mitral rheumatic disease and infectious endocarditis: case report

Apesar de pouco frequente, a ruptura de músculo papilar é uma condição associada à regurgitação mitral importante, sendo causa grave de insuficiência cardíaca aguda, necessitando de diagnóstico e intervenção cirúrgica precoce. Neste relato, apresentamos um caso de paciente portador de febre reumática associado à endocardite infecciosa, que evoluiu com insuficiência mitral importante, secundária à ruptura do músculo papilar anterolateral.

Although its low frequency, the papillary muscle rupture is a condition associated with severe mitral regurgitation and cause of acute heart failure and need for urgent surgical intervention. We present a case of severe mitral regurgitation due to the anterolateral papillary muscle rupture secondary to rheumatic mitral valve disease and infectious endocarditis.

Structural characteristics of the tendinous cord-papillary muscle junction in healthy and hypertensive rats.

Although the myotendinous junction (MTJ) of skeletal striated muscle is well known, more detailed studies regarding the structure of the cardiac MTJ are scarce. The objective of the present study was to investigate the morphological characteristics of the MTJ in hearts of healthy and hypertensive (SHR) female rats using histological, ultrastructural and three-dimensional (SEM) methods, as well as to evaluate the expression of vinculin by immunofluorescence. In the two groups, light microscopy showed branching tendinous cords and collagen bundles penetrating the apex of the finger-like projections of the papillary muscle. SEM analysis revealed an enlarged apex of the papillary muscle in SHR which was not observed in healthy animals. The loss of force transmission appears to be compensated by the amplified connection between the papillary muscle and valvular collagen. A large number of intercalated disks close to the fiber apex, small amounts of an amorphous intercellular substance and numerous vesicles were observed in SHR. In these animals, the expression of vinculin was more marked showing a regular distribution and a pattern of transverse striations along the sarcolemma. The presence of this protein in transverse bands suggests that vinculin surrounds myofibrils in the region of the Z band. Vinculin staining was also more marked in the region of the tendinous cord-papillary muscle junctions of SHR compared to control animals. Vinculin was quantified by electrophoresis and higher amounts of this protein were observed in SHR compared to control animals.

Ultrasonic tissue characterization in acute coronary syndromes.

BACKGROUND: Ultrasonic tissue characterization (UTC), as evaluated through integrated backscatter, has the potential to detect precocious structural damage to myocardial tissue. In acute coronary syndromes (ACS) this technique is attracting attention due to its potential to evaluate myocardial viability. OBJECTIVE: To evaluate the role of UTC in the emergency department. METHODS: We studied 28 individuals, classified in three groups: Group I (13; 52.2+/-15.5 years) with patients admitted with chest pain who have negative evaluation for acute coronary syndrome; Group II (9; 54.2+/-10.0 years) with acute myocardial infarction in right coronary artery territory; and Group III (6; 62.1+/-9.1 years) with acute myocardial infarction in the anterior descendent branch territory. For each individual, we analyzed four segments in the short axis view at the papillary muscle level (1--anterior; 2--anterior-lateral; 3--inferior e 4--septal), for the following parameters: corrected coefficient, amplitude, delay index and IBS pattern. RESULTS: The acute myocardial isquemic process in its initial phase was not detected by the corrected coefficient or by the IBS amplitude. The sincronicity parameters (delay index and IBS pattern), more sensible, were partially able to identify changes in more extension regions of myocardial infarction. CONCLUSION: More studies should be conducted to evaluate these parameters in the early phase of acute coronary syndromes.

Caracterização tecidual ultra-sônica em síndromes coronarianas agudas / Ultrasonic tissue characterization in acute coronary syndromes

FUNDAMENTO: A caracterização tecidual ultra-sônica (CTU), avaliada pelo integrated backscatter, tem o potencial de detectar precocemente alterações estruturais no tecido miocárdico. Nas síndromes coronarianas agudas (SCA) esta técnica tem atraído atenção pelo potencial de detectar viabilidade miocárdica. OBJETIVO: Analisar o potencial da CTU em detectar alterações precoces na sala de urgência. MÉTODOS: Foram estudados 28 indivíduos, divididos em três grupos: grupo I (13; 52,2±15,5 anos) composto por pacientes encaminhados para a sala de urgência com suspeita clínica de SCA, que foi descartada na evolução; grupo II (9; 54,2±10 anos) com infarto agudo de coronária direita e grupo III (6; 62,1±9,1 anos) com infarto agudo de ramo descendente anterior da coronária esquerda. Para cada indivíduo incluído no estudo, foram avaliados quatro segmentos no eixo curto no plano dos músculos papilares (1 - anterior médio; 2 - ântero-lateral médio; 3 - inferior médio e 4 - septal médio), obtendo-se o coeficiente corrigido, a amplitude de variação do IBS, o índice de retardo da variação e o padrão da variação. RESULTADOS: As alterações decorrentes do processo isquêmico em sua fase inicial não foram detectadas pelo coeficiente corrigido ou pela alteração da amplitude de variação do IBS. Os parâmetros de sincronicidade (índice de retardo e padrão de variação), no entanto, por serem mais sensíveis, foram parcialmente capazes em regiões de infartos mais extensos. CONCLUSÃO: Maiores estudos sobre o comportamento destes índices na fase aguda das SIMI são necessários.

BACKGROUND: Ultrasonic tissue characterization (UTC), as evaluated through integrated backscatter, has the potential to detect precocious structural damage to myocardial tissue. In acute coronary syndromes (ACS) this technique is attracting attention due to its potential to evaluate myocardial viability. OBJECTIVE: To evaluate the role of UTC in the emergency department. METHODS: We studied 28 individuals, classified in three groups: Group I (13; 52.2±15.5 years) with patients admitted with chest pain who have negative evaluation for acute coronary syndrome; Group II (9; 54.2±10.0 years) with acute myocardial infarction in right coronary artery territory; and Group III (6; 62.1±9.1 years) with acute myocardial infarction in the anterior descendent branch territory. For each individual, we analyzed four segments in the short axis view at the papillary muscle level (1 - anterior; 2 - anterior-lateral; 3 - inferior e 4 - septal), for the following parameters: corrected coefficient, amplitude, delay index and IBS pattern. RESULTS: The acute myocardial isquemic process in its initial phase was not detected by the corrected coefficient or by the IBS amplitude. The sincronicity parameters (delay index and IBS pattern), more sensible, were partially able to identify changes in more extension regions of myocardial infarction. CONCLUSION: More studies should be conducted to evaluate these parameters in the early phase of acute coronary syndromes.

[Cardiac papillary fibroelastoma. Experience of an institution]. / Fibroelastoma papilífero. Experiência de uma instituição.

Primary intracardiac tumors are rare, with prevalence between 0.0017% and 0.19% from non-selected autopsy studies. Approximately 75% are benign and almost half of them are myxomas. The remaining tumors are divided among rhabdomyomas, lipomas and fibroelastomas. Myxomas are the most common intracardiac tumors in adult age and rhabdomyomas the most common among pediatric population. Papillary fibroelastoma (PFE) is a relative rare benign heart tumor, corresponding to approximately 8% of intracardiac tumors. They most commonly manifested in cardiac valves. In the past, they either consisted of necropsy findings or were found in surgical procedures at random. In vivo diagnosis was sporadic. With the improvement of echocardiography techniques, PFE has been more frequently diagnosed. They are usually described as a movable, pedunculate, well-delimited mass and with predilection for valve endocardium. Therapeutic proposal, when they are pedunculate, is surgical resection, preventing cerebral, pulmonary, coronary or peripheral embolic phenomena. Five cases diagnosed in our institution, in the period from August 1995 to June 2004, will be presented.

Myocardial dysfunction induced by food restriction is related to morphological damage in normotensive middle-aged rats.

Previous works from our laboratory have revealed that food restriction (FR) promotes discrete myocardial dysfunction in young rats. We examined the effects of FR on cardiac function, in vivo and in vitro, and ultrastructural changes in the heart of middle-aged rats. Twelve-month-old Wistar-Kyoto rats were fed a control (C) or restricted diet (daily intake reduced to 50% of the control group) for 90 days. Cardiac performance was studied by echocardiogram and in isolated left ventricular (LV) papillary muscle by isometric contraction in basal condition, after calcium chloride (5.2 mM) and beta-adrenergic stimulation with isoproterenol (10(-6) M). FR did not change left ventricular function, but increased time to peak tension, and decreased maximum rate of papillary muscle tension development. Inotropic maneuvers promoted similar effects in both groups. Ultrastructural alterations were seen in most FR rat muscle fibers and included, absence and/or disorganization of myofilaments and Z line, hyper-contracted myofibrils, polymorphic and swollen mitochondria with disorganized cristae, and a great quantity of collagen fibrils. In conclusion, cardiac muscle sensitivity to isoproterenol and elevation of extracellular calcium concentration is preserved in middle-aged FR rats. The intrinsic muscle performance depression might be related to morphological damage.

Fibroelastoma papilífero: experiência de uma instituição / Cardiac papillary fibroelastoma: experience of an institution

Os tumores cardíacos primários do coração são raros, com uma prevalência entre 0,0017 por cento e 0,19 por cento dos estudos de autópsia não selecionados. Cerca de 75 por cento são tumores benignos e quase a metade são mixomas. Os restantes se dividem entre rabdomiomas, lipomas e fibroelastomas. Os mixomas são os tumores cardíacos mais comuns na idade adulta e os rabdomiomas, os mais comuns da população pediátrica. O fibroelastoma papilífero (FEP) é um tumor benigno do coração, relativamente raro, correspondendo a aproximadamente 8 por cento dos tumores cardíacos. São os que mais comumente acometem as valvas cardíacas . No passado, consistiam de achados de necropsia ou eram encontrados em procedimentos cirúrgicos ao acaso. O diagnóstico in vivo era esporádico². Com o aprimoramento das técnicas de ecocardiografia, o FEP tem sido diagnosticado com maior freqüência. São, geralmente, descritos como uma massa móvel, pedunculada, bem delimitada e com predileção pelo endocárdio valvar. A proposta terapêutica, quando pedunculados, é a ressecção cirúrgica, visando a prevenção de fenômenos embólicos cerebrais, pulmonares, coronarianos ou periféricos1,3. Serão apresentados cinco casos diagnosticados em nossa instituição, no período de agosto de 1995 a junho de 2004.

Volume overload influence on hypertrophied myocardium function.

The aim of this study was to demonstrate that hypertrophied cardiac muscle is more sensitive to volume-overload than normal cardiac muscle. We assessed the mechanical function of isolated left ventricular papillary muscle from male spontaneously hypertensive rats (SHR) and age-matched normotensive Wistar-Kyoto rats (WKY) submitted to volume overload caused by aortocaval fistula (ACF) for 30 days. Muscles were perfused with Krebs-Henseleit solution at 28 degrees C and studied isometrically at a stimulation rate of 0.2 Hz. The ACF increased the right and left ventricular weight-to-body weight ratio in WKY rats; it also promoted right ventricular hypertrophy and further increased the basal hypertrophy in the left ventricle from SHR. The arterial systolic pressure was greater in SHR than in WKY rats, and decreased with ACF in both groups. Developed tension (DT) and maximum rate of DT (+dT/dt) were greater in the SHR-control than in the WKY-control (P < 0.05); the time from peak tension to 50% relaxation (RT 1/2) was similar in these animals. ACF did not change any parameters in the SHR group and increased the resting tension in the WKY group. However, the significant difference observed between myocardial contraction performance in WKY-controls and SHR-controls disappeared when the SHR-ACF and WKY-controls were compared. Furthermore, RT 1/2 increased significantly in the SHR-ACF in relation to the WKY-controls. In conclusion, the data lead us to infer that volume-overload for 30 days promotes more mechanical functional changes in hypertrophied muscle than in normal cardiac muscle.