Eletrocardiografia basal e após exercício em cães braquicefálicos / Baseline and post exercise electrocardiography in brachycephalic dogs

Background: The brachycephalic dog breeds have been increasing in Brazil, and these animals are predisposed to present the brachycephalic dog syndrome, consisting of anatomical defects that lead to physiological changes and clinical signs such as wheezing, dyspnea, and hypoxia. Electrocardiography (ECG) is a simple test that can detect disturbances in the electrical activity of the heart, including changes present in hypoxia. The brachycephalic dog syndrome can lead to pulmonary hypertension due to hypoxia. Based on this, the present work aimed to evaluate the ECG of brachycephalic dogs in search of significant changes in heart rhythm, ECG waves, and cardiac axis. Materials, Methods & Results: Twenty-nine dogs were evaluated in this study, 19 brachycephalic and 10 mesaticephalic, after approval by an ethics committee the animals were selected. Electrocardiographic examinations were performed in 2 stages, at rest and immediately after a 3-min trot. The exam was performed with a computerized electrocardiograph, with a standard time of 5 min. The standard positioning for performing the examination was the right lateral decubitus position. To improve the electrical conductivity, 70% alcohol was used between the animal's skin and the electrodes. In statistical analysis, paired t test was performed for comparison of the same group before and after exercise and unpaired t test between groups at the same moments, considering P < 0.05 as significant. Nineteen brachycephalic animals were evaluated, 10 Pugs and 9 French Bulldogs, 9 males and 10 females. The mean age was 3.4 ± 1.8 years; and the mean weight was 12.5 kg ± 2.7 kg. In the control group, consisting of ten mesaticephalic animals, all were non-breed, three males and seven females; the mean age and weight in this group were 4.4 ± 1.5 years and 7.5 kg ± 0.5 kg, respectively. There was a significant increase in heart rate (bpm) after exercise in brachycephalic dogs (baseline: 119.3 ± 4.3; after exercise: 135.1 ± 4.9; P = 0.0005). The same occurred for P wave amplitude (mV) (baseline: 0.20 ± 0.01; after exercise: 0.22 ± 0.01; P = 0.0001). These differences were not found in the control group. There were no alterations in the duration of the P wave, PR interval, QRS complex, and QT interval, and all were within normal values for the species in both groups. The R-wave amplitude remained unaltered and within normal values in both the control and brachycephalic groups. Discussion: The elevation in heart rate may be associated with the chemoreflex secondary to the increased demand for oxygenation during exercise and the hypoxia generated by it. The increase in P amplitude suggests right atrial overload. The P wave corresponds to the atrial depolarization and its amplitude corresponds to the electrical activity in the right atrium. Thus, it is possible to relate the increase in P amplitude and heart rate to the hypoxia caused by exercise in brachycephalic, since this hypoxia results in chemoreceptor activation that increases chronotropism and heart rate. Also, there may be increased pressure in the pulmonary trunk, this increased pressure occurs due to vasoconstriction generated as a reflex to hypoxia in the pulmonary alveoli, leading to a possible picture of acute pulmonary hypertension that, in a cascade effect, leads to hypertrophy and dilation of the right ventricle, increased strength of contractility and ejection affecting the tricuspid valve causing a reflux and consequent overload of the right atrium.

Felinos portadores de cardiomiopatia fenótipo hipertrófica - eixo elétrico da onda P / Cats with hypertrophic phenotype cardiomyopathy - P-wave electrical axis

Background: Hypertrophic phenotype cardiomyopathy is the most common heart disease in cats. Although the echocardiogram is the gold standard test for diagnosing fHCM, patients with the disease may have electrocardiographic changes. Despite being reported in most 12-lead electrocardiograms, the P wave axis generally receives little attention when compared to other wave parameters. We performed a Doppler echocardiographic and electrocardiographic study in cats, in order to verify the presence of correlation between the electrical axis average P wave and the presence of fCMH, aiming to investigate the possibility of its aid in the early diagnosis of cardiac disorders. Materials, Methods & Results: One hundred cats of different breeds, ages, males and females were evaluated. Those animals with a history of previous disease other than hypertrophic cardiomyopathy were excluded from the study. The groups were formed after obtaining the results of the echocardiographic examination. Eight of the 100 cats did not allow echocardiographic evaluation, and the remaining 92 were divided into 2 groups (control group, n = 64 and heart disease group, n = 28) after the examination. Of these 92 animals, 28 cats had the hypertrophic cardiomyopathy phenotype. The electrocardiographic examination was performed after the allocation of animals into groups lasting 5 min with the recording of tracings for later interpretation. To calculate the axis of the P wave, leads D1 and D3 were used, measuring the amplitude of the P wave in these leads and calculating the resulting amplitude. All cats studied had mean electrical axis of the P wave within the normal range for the species (0º to 90º). Based on mean electrical axis P wave values, there was no significant difference between groups. The control group had a median of 63.7° with a maximum value of 80°, a minimum value of 60° and a mean of 65.1°. The fCMH group had a median of 68.7° with a maximum value of 85.3°, a minimum value of 56.3° and a mean of 68.8°. Of the fCMH group, 3 cats had increased P wave duration (50.33 ± 5.77 ms), suggesting left atrial overload, and 13 cats had increased QRS complex duration (66.30 ± 11.23 ms). Also, 18 cats (Control group: 11; fCMH group: 7) showed T wave amplitude greater than 25% of R, suggesting the presence of myocardial hypoxia and/or electrolyte disturbance. One cat had a prolonged PR interval (from the fCMH group). As for the QT interval, 6 cats had an interval < 120 (2 from the control group and 4 from the affected group) and 3 had an interval > 180 (1 from the control group and 2 from the affected group). The ST segment remained isoelectric in all segments. As for the mean electrical axis of the QRS complex, 5 cats (10.42%) had axis deviation to the right (control: 1; fCMH: 4) suggesting right ventricular overload; 7 cats (14.58%) had left axis deviation (control: 5; fCMH: 2), suggestive of left ventricular overload; and 36 cats (75%) had a normal mean electrical axis. Discussion: Based on the results obtained in the present study, it can be concluded that screening studies in asymptomatic felines should be increasingly implemented in the veterinary clinical routine, since the frequency found was high (30.44%) and that patients may remain asymptomatic for years until the development of signs. It should be concluded that there was no correlation between the mean electric axis of P-wave and the presence of subclinical phenotype hypertrophic cardiomyopathy. Therefore, more studies are needed, with felines at different stages of the disease, to evaluate whether this electrocardiographic measurement allows us to assist in its diagnosis, since it is a feasible measure in cats. Furthermore, it is concluded that the electrocardiogram should be used as an aid method in the diagnosis of the disease and not as a screening test.

Eletrocardiografia computadorizada em cadelas com tumores mamários / Electrocardiography in bitches with mammary tumors

The incidence of cancer has increased due to greater longevity of the animals as a consequence of better control of other diseases, improvement of nutrition and good practices in preventive medicine. Malignant tumors can cause paraneoplastic syndrome such as hypercalcemia, anemia, cachexia, among others and consequent cardiovascular disorders. The electrocardiography (ECG) is a complementary exam that can reveal with its traces these rhythmic disorders. Based on that, the objective of this study was to evaluate the ECG in bitches with mammary tumors in order to detect in which type of tumor would be found significant changes as in cardiac rhythm, ECG waves, segments or cardiac axis. Twenty-nine female dogs were used in this study, being 19 bitches with mammary tumor, and they were allocated in three groups: G1: control group (n = 10), G2: benign neoplasia group (n = 6) and G3: malignant neoplasia group (n = 13). The most prevalent type of neoplasia in G2 was the benign mixed tumor (83%), followed by adenoma (17%) whereas in G3: carcinoma in mixed tumor (61%); papillary carcinoma (23%). Regarding cardiac rhythm, it was found sinus arrhythmia (SA) and normal sinus rhythm (NS): G1: 50% SA and 50% NS; G2: 67% SA and 33% NS; G3: 54% SA and 46% NS. No ventricular or atrial arrhythmias were detected. For other parameters in G1, G2 and G3, respectively (mean ± Std error): FC (bpm): 110±9.2, 120 ± 8.5, 124±7,5; P (ms): 48 ± 1.6, 51 ± 1.8, 50 ± 1.2; P (mV) 0.19 ± 0.02, 0.2 ± 0.02, 0.19 ± 0.02; PR (ms): 94 ± 4.3, 93 ± 5.5, 89 ± 3.9; QRS (ms): 56 ± 1.54, 60 ± 4, 62 ± 1.2; R (mV): 1.1 ± 0.06, 1.2 ± 0.24, 0.9 ± 0.13; QT (ms): 203 ± 9.4; 204 ± 7.9; 182 ± 15.6; and cardiac axis (°): 66 ± 6.2, 61 ± 7.9, 70 ± 7.5. There were no significant differences for all cardiac parameters and also for ST interval and T wave morphology. All electrocardiographic parameters found are in accordance with other studies carried out in the canine species. The results regarding tumor types differ from what was found in another study, in which in 18 bitches with mammary tumors, 55% were benign, with prevalence of adenomas (38%) followed by benign mixed tumors, and 45% malignant, with adenocarcinoma prevailing (22%). In another study, it was verified in 63 bitches the predominance of tubular carcinoma (26.56%) and carcinoma in mixed tumors (23.44%). Diverging from the electrocardiographic parameters of this study, a significant difference was found in the R wave amplitude value in the research by Barros et al., (2015) who performed computerized electrocardiography in 50 dogs, not only with mammary neoplasms (55% mammary carcinomas), but also in mastocytomas, lymphomas, benign tumors and other sarcomas. This author found out that the R wave amplitude values of the neoplasia group were lower when compared to the control group. In addition, we suspect that other types of tumors could result in more paraneoplastic syndrome than the mammary neoplasms found in this research. Neoplasms as lymphomas (T cells), apocrine gland anal sac adenocarcinomas, multiple myelomas and thymomas are known as a cause of hypercalcemia of malignancy and histiocytic sarcomas, myelomas, leukemia and lymphomas causing anemia. In conclusion, ECG has no changes in benign or malignant mammary tumors in dogs. However, this fact does not exclude the importance of its performance in pre-anesthetic evaluations. Further studies with a larger sample including the clinical staging of these bitches with a balanced number of animals with low and high staging are suggested.(AU)

Long-axis fractional shortening and mitral annulus motion in dogs / Fração de encurtamento longitudinal e movimento anular mitralem cães

Ventricular systolic dynamics involves the contraction of transverse and longitudinal myocardial fibers. Unfortunately, only the activity of the transverse myocardial fibers is foreseen by the standard systolic echocardiographic parameters. Although strain and strain rate have been used to assess the radial, circumferential and longitudinal planes of cardiac contraction, such analysis requires advanced equipment which is not always available in veterinary medicine. On the contrary, some unusual parameters may be recorded via standard methodology, allowing for the specific evaluation of left ventricular longitudinal contractility. In this study, the longitudinal contractile activity was evaluated using the long-axis fractional shortening and the mitral annulus motion, which were compared with several standard echocardiographic parameters in 14 beagles, including seven with asymptomatic mitral valve disease. The long-axis fractional shortening was positively correlated with both the mitral annulus motion and the end-diastolic left-ventricular diameter. Also, a significant correlation was found to exist between the mitral annulus motion and the left-ventricular end-diastolic diameter, which is likely supportive of its preload dependency. Even though no difference was documented in either mitral annulus motion or long-axis fractional shortening between healthy dogs and dogs with mitral valve disease, the latter only included animals with minimal cardiac remodeling, with no overt compromiseof systolic function. Since it is possible to obtain these two parameters with any echocardiographic equipment, their inclusion in the routine exam would probably add information regarding the activity of the longitudinal myocardial fibers, whose functional deterioration supposedly occurs prior to theimpairment of transverse fibers.

A dinâmica ventricular sistólica envolve a contração de fibras miocárdicas transversais e longitudinais e, infelizmente, os parâmetros ecocardiográficos de função sistólica utilizados rotineiramente estão focados apenas na atividade das fibras transversais. Embora a deformação e a taxa de deformação miocárdicas venham sendo utilizadas para avaliar a contração cardíaca nos planos radial, circunferencial e longitudinal, tal análise requer equipamentos avançados que nem sempre estão disponíveis na Medicina Veterinária. Por outro lado, alguns parâmetros não usuais podem ser quantificados valendo-se de metodologia convencional, permitindo avaliar especificamente a função contrátil longitudinal do ventrículo esquerdo. Neste estudo, a atividade contrátil longitudinal foi avaliada por meio da fração de encurtamento longitudinal e do movimento anular mitral, os quais foram comparados com diversas variáveis ecocardiográficas convencionais em 14 Beagles, sendo sete deles portadores de doença valvar mitral assintomática. A fração de encurtamento longitudinal apresentou correlação positiva com o movimento anular mitral e com o diâmetro do ventrículo esquerdo em diástole. Também houve correlação significativa entre o movimento anular mitral e o diâmetro ventricular esquerdo em diástole, o que pode sugerir sua dependência da pré-carga. Embora não tenham sido observadas diferenças no movimento anular mitral e na fração de encurtamento longitudinal entre cães saudáveis e valvulopatas, há que se enfatizar que os animais com doença mitral apresentavam apenas mínimoremodelamento cardíaco, sem quaisquer indícios de comprometimento da função sistólica.

Long-axis fractional shortening and mitral annulus motion in dogs / Fração de encurtamento longitudinal e movimento anular mitralem cães

Ventricular systolic dynamics involves the contraction of transverse and longitudinal myocardial fibers. Unfortunately, only the activity of the transverse myocardial fibers is foreseen by the standard systolic echocardiographic parameters. Although strain and strain rate have been used to assess the radial, circumferential and longitudinal planes of cardiac contraction, such analysis requires advanced equipment which is not always available in veterinary medicine. On the contrary, some unusual parameters may be recorded via standard methodology, allowing for the specific evaluation of left ventricular longitudinal contractility. In this study, the longitudinal contractile activity was evaluated using the long-axis fractional shortening and the mitral annulus motion, which were compared with several standard echocardiographic parameters in 14 beagles, including seven with asymptomatic mitral valve disease. The long-axis fractional shortening was positively correlated with both the mitral annulus motion and the end-diastolic left-ventricular diameter. Also, a significant correlation was found to exist between the mitral annulus motion and the left-ventricular end-diastolic diameter, which is likely supportive of its preload dependency. Even though no difference was documented in either mitral annulus motion or long-axis fractional shortening between healthy dogs and dogs with mitral valve disease, the latter only included animals with minimal cardiac remodeling, with no overt compromiseof systolic function. Since it is possible to obtain these two parameters with any echocardiographic equipment, their inclusion in the routine exam would probably add information regarding the activity of the longitudinal myocardial fibers, whose functional deterioration supposedly occurs prior to theimpairment of transverse fibers.(AU)

A dinâmica ventricular sistólica envolve a contração de fibras miocárdicas transversais e longitudinais e, infelizmente, os parâmetros ecocardiográficos de função sistólica utilizados rotineiramente estão focados apenas na atividade das fibras transversais. Embora a deformação e a taxa de deformação miocárdicas venham sendo utilizadas para avaliar a contração cardíaca nos planos radial, circunferencial e longitudinal, tal análise requer equipamentos avançados que nem sempre estão disponíveis na Medicina Veterinária. Por outro lado, alguns parâmetros não usuais podem ser quantificados valendo-se de metodologia convencional, permitindo avaliar especificamente a função contrátil longitudinal do ventrículo esquerdo. Neste estudo, a atividade contrátil longitudinal foi avaliada por meio da fração de encurtamento longitudinal e do movimento anular mitral, os quais foram comparados com diversas variáveis ecocardiográficas convencionais em 14 Beagles, sendo sete deles portadores de doença valvar mitral assintomática. A fração de encurtamento longitudinal apresentou correlação positiva com o movimento anular mitral e com o diâmetro do ventrículo esquerdo em diástole. Também houve correlação significativa entre o movimento anular mitral e o diâmetro ventricular esquerdo em diástole, o que pode sugerir sua dependência da pré-carga. Embora não tenham sido observadas diferenças no movimento anular mitral e na fração de encurtamento longitudinal entre cães saudáveis e valvulopatas, há que se enfatizar que os animais com doença mitral apresentavam apenas mínimoremodelamento cardíaco, sem quaisquer indícios de comprometimento da função sistólica. (AU)

Correlation between systolic function and presence of myofibroblasts in doxorubicin-induced cardiomyopathy / Correlação entre função sistólica e presença de miofibroblastos na cardiomiopatia induzida pela doxorrubicina

Cardiotoxicity induced by doroxubicin generates systolic disfunction and myocardial remodeling with presence of myofibroblasts. These cells are thought to be attracted to the injured heart to avoid the development of congestive heart failure. The objective of this study was to evaluate the systolic dysfunction generated by doxorubicin through Doppler echocardiography, and its correlation with the presence of myofibroblasts in the myocardium. Twenty-five New Zealand White rabbits were divided into two groups (control, and treated with doxorubicin). The drug was administered for six weeks; Doppler echocardiography was performed before the first, and after the last administration of doxorubicin. Immuno detection of myofibroblasts was performed by immunohistochemistry. The treated group exhibited significant reduction in systolic function as assessed by Doppler echocardiography, and increased frequency of myofibroblasts, which were present in similar amounts in the left ventricle, interventricular septum, and right ventricle. There was a significant negative correlation between number of myofibroblasts in the interventricular septum and in the left ventricle with systolic function indices, which reveals that the higher the number of fibroblasts, the worst systolic function is in rabbits treated with doxorubicin. Increase in myofibroblast numbers was not sufficient to preserve systolic function.(AU)

A cardiotoxicidade induzida pela doxorrubicina gera disfunção sistólica e remodelamento miocárdico, com presença de miofibroblastos. Acredita-se que essas células sejam atraídas para a não evolução do quadro de insuficiência cardíaca congestiva. O objetivo do presente trabalho foi avaliar a função sistólica gerada pela doxorrubicina por meio da ecodopplercadiografia e correlacioná-la com a presença de miofibroblastos no miocárdio. Foram utilizados 25 coelhos da raça Nova Zelândia, alocados em dois grupos (controle e tratados com doxorrubicina). O fármaco foi administrado por seis semanas e a ecodopplercardiografia foi realizada no momento zero e após a última administração da doxorrubicina. A imunodetecção dos miofibroblastos foi realizada por imuno-histoquímica. Houve redução significativa na função sistólica, observada na ecodopplercardiografia e aumento na imundetecção dos miofibroblastos nos animais tratados, na mesma intensidade no ventrículo esquerdo, septo interventricular e ventrículo direito. Houve correlação negativa significativa entre o número de miofibroblastos no septo interventricular e no ventrículo esquerdo com os índices de função sistólica, revelando que quanto mais miofibroblastos presentes, pior é a função sistólica de coelhos tratados com doxorrubicina. O aumento do número de miofibroblastos não foi suficiente para manutenção da função sistólica.(AU)

Disfunção miocárdica relacionada à insuficiência pancreática exócrinaem cão - relato de caso / Myocardial dysfunction related to exocrine pancreatic insufficiency in dogs - case report

Insuficiência Pancreática Exócrina (IPE) é um tipo de enfermidade gastrointestinal crônica que promovediversas alterações no organismo. O presente relato refere-se ao atendimento de um cão da raça PastorAlemão com diagnóstico de IPE com sinais clínicos de intolerância a exercícios e de insuficiência miocárdicaobservados em exames complementares antes e após a instituição do tratamento para IPE. Osautores discutem a possível participação da colecistoquinina e do déficit de taurina no desenvolvimentoda insuficiência miocárdica.(AU)

The exocrine pancreatic insufficiency (EPI) is a chronic gastrointestinal disease that promotes severalconsequences to the organism. The present case report mentions the attendance of a German Shepherddog with EPI diagnosis, intolerance to exercises and cardiac alterations in complementary examinations,before treatment. The authors argue the participation of cholecystokinin and deficit of taurine on thedevelopment of this cardiac disturbance.(AU)

Disfunção miocárdica relacionada à insuficiência pancreática exócrinaem cão - relato de caso / Myocardial dysfunction related to exocrine pancreatic insufficiency in dogs - case report

Insuficiência Pancreática Exócrina (IPE) é um tipo de enfermidade gastrointestinal crônica que promovediversas alterações no organismo. O presente relato refere-se ao atendimento de um cão da raça PastorAlemão com diagnóstico de IPE com sinais clínicos de intolerância a exercícios e de insuficiência miocárdicaobservados em exames complementares antes e após a instituição do tratamento para IPE. Osautores discutem a possível participação da colecistoquinina e do déficit de taurina no desenvolvimentoda insuficiência miocárdica.

The exocrine pancreatic insufficiency (EPI) is a chronic gastrointestinal disease that promotes severalconsequences to the organism. The present case report mentions the attendance of a German Shepherddog with EPI diagnosis, intolerance to exercises and cardiac alterations in complementary examinations,before treatment. The authors argue the participation of cholecystokinin and deficit of taurine on thedevelopment of this cardiac disturbance.

Indução da cardiomiopatia dilatada com Doxorrubicina em modelo experimental com coelhos

A cardiomiopatia dilatada (CMD) é uma enfermidade caracterizada pelo aumento das câmaras cardíacas e disfunção sistólica. Devido ao fato dessa doença ainda apresentar prognóstico desfavorável aos seres humanos e animais, há a necessidade de criação de modelos experimentais da doença para o teste de novas terapias, como novos fármacos e células-tronco. No trabalho em tela, avaliou-se a indução da cardiomiopatia dilatada em coelhos com a administração de duas doses diferentes de doxorrubicina, por meio de achados radiográficos, eletrocardiográficos, ecodopplercardiográficos e histopatológicos. Foi observada redução significativa na função sistólica após seis semanas de indução, com diminuição da fração de encurtamento e de ejeção. Os achados histopatológicos demonstraram que a cardiotoxicidade decorrente do uso da doxorrubicina desenvolve-se tanto no ventrículo esquerdo quanto no septo interventricular e ventrículo direito. Os resultados desse estudo mostram que a espécie leporina pode ser utilizada como modelo experimental para indução da cardiomiopatia dilatada com doxorrubicina, na dose de 1mg/kg administrada duas vezes por semana por um período de seis semanas consecutivas

Dilated cardiomyopathy (DCM) is a disease characterized by increased cardiac chambers and systolic dysfunction. Because of the poor prognosis for humans and animals, studies with new therapeutic modalities have aroused great interest. Thus, there is a need for creation of experimental models of the disease for testing new therapies as new drugs and stem cells. This study was conceived to evaluate an experimental model of dilated cardiomyopathy induced in rabbits with administration of two different doses of chemotherapeutic agent doxorubicin, through radiography, electrocardiography, echodopplercardiography and histopathological findings. Significant reduction in systolic function after six weeks in treated animals, with decrease of ejection and shortening fraction were observed. The histopathologic findings demonstrated that cardiotoxicity due to administration of doxorrubicin occurs in left ventricle, as well as in interventricular septum and right ventricle. The results showed that rabbits can be used as an experimental model of induction of DCM with doxorrubicin, in the dose of 1mg/kg twice a week for a period of six consecutive weeks

Primary cardiac lymphoma in dog / Linfoma cardíaco primário em cão

Lymphomas are malignant neoplasm characterized by proliferation of lymphocytes that originate primarily in lymphoid organ such as lymph nodes, liver, spleen and bone marrow. However the feature of continuous migration of lymphocytes in different organs, this tumor can develop in any organ. Although lymphoma is a very common hematopoietic neoplasm in dogs, cardiac location is rare. The diagnosis of primary cardiac lymphoma may be performed when there is involvement of the heart and / or the pericardium without evidence of  involvement in other organs. In veterinary medicine there are few reports on the diagnosis, treatment and prognosis of cardiac lymphoma. Therefore, the purpose of this report is to describe a case of cardiac lymphoma in which the patient responded favorably to chemotherapy employee with disease-free interval of 19 months and highlight the importance of including this neoplasm in the differential diagnosis of diseases that affect the cardiovascular system.

Os linfomas são neoplasias caracterizadas pela proliferação maligna de linfócitos, que originamse principalmente em órgão linfóides como linfonodos, fígado, baço e medula óssea. Entretanto pela característica de contínua migração dos linfócitos por diferentes órgãos, esta neoplasia pode se desenvolver em qualquer órgão. Embora o linfoma seja a neoplasia hematopoiética de maior incidência em cães, a localização cardíaca é rara. O diagnóstico de linfoma cardíaco primário pode ser realizado quando há envolvimento do coração e/ou pericárdio sem evidências de ocorrência de órgãos linfáticos ou extranodais. Em medicina veterinária existem poucos relatos sobre o diagnóstico, tratamento e prognóstico desta neoplasia cardíaca. Portanto o objetivo do presente relato é descrever um caso de linfoma cardíaco em que o paciente respondeu favoravelmente ao tratamento quimioterápico empregado com intervalo livre de doença de 19 meses e salientar a importância de incluir essa neoplasia na lista de diagnósticos diferenciais de doenças que acometem o sistema cardiovascular.