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1.
Tex Heart Inst J ; 45(2): 102-105, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29844744

RESUMO

A diastolic paradoxical jet flow, often seen in patients with hypertrophic cardiomyopathy, is a unique flow from the apex toward the base of the left ventricle during isovolumic relaxation. To date, this phenomenon appears to have been noninvasively detected only on echocardiograms. We report the case of a 43-year-old man with hypertrophic cardiomyopathy and a diastolic paradoxical jet flow, in whom cardiac auscultation revealed a soft S4, a systolic ejection murmur, and a low-pitched early diastolic murmur immediately after S2 at the apex. On comparing his echocardiographic findings with those on phonocardiograms and apexcardiograms, we confirmed that the unusual murmur coincided with the diastolic jet flow. To our knowledge, this is the first case in which heart murmurs associated with a diastolic paradoxical jet flow have been clearly described. Because these flows can increase the risk of adverse outcomes, detecting any associated murmurs by methods other than echocardiography is worthwhile, even in the era of advanced imaging techniques.


Assuntos
Velocidade do Fluxo Sanguíneo/fisiologia , Cardiomiopatia Hipertrófica/complicações , Ecocardiografia Doppler/métodos , Sopros Cardíacos/diagnóstico , Ventrículos do Coração/fisiopatologia , Adulto , Cardiomiopatia Hipertrófica/diagnóstico , Cardiomiopatia Hipertrófica/fisiopatologia , Diástole , Sopros Cardíacos/etiologia , Sopros Cardíacos/fisiopatologia , Ventrículos do Coração/diagnóstico por imagem , Humanos , Masculino
3.
Tex Heart Inst J ; 43(1): 65-8, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27047289

RESUMO

Immunosuppression is the typical measure to prevent rejection after heart transplantation. Although rejection is the usual cause of cardiac hypertrophy, numerous other factors warrant consideration. Calcineurin inhibitors rarely cause hypertrophic cardiomyopathy; the few relevant reports have described children after orthotopic kidney or liver transplantation. We present the case of a 73-year-old woman, an asymptomatic orthotopic heart transplantation patient, in whom chronic immunosuppression with prednisone and cyclosporine apparently caused a phenotype of hypertrophic cardiomyopathy. The natural course of her midapical hypertrophy was revealed by single-photon-emission computed tomography, positron-emission tomography, and 2-dimensional echocardiography. Clinicians and radiographers should be alert to progressive left ventricular hypertrophy and various perfusion patterns in heart transplantation patients even in the absence of underlying coronary artery disease. Toward this end, we recommend that advanced imaging methods be used to their fullest extent.


Assuntos
Cardiomiopatia Hipertrófica/cirurgia , Transplante de Coração/efeitos adversos , Hipertrofia Ventricular Esquerda/etiologia , Imagem Multimodal/métodos , Idoso , Cardiomiopatia Hipertrófica/diagnóstico , Feminino , Humanos , Hipertrofia Ventricular Esquerda/diagnóstico , Hipertrofia Ventricular Esquerda/fisiopatologia , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada de Emissão de Fóton Único
4.
Arq. bras. cardiol ; 106(2): 121-129, Feb. 2016. tab
Artigo em Português | LILACS | ID: lil-775096

RESUMO

Abstract Background: Heart failure is accompanied by abnormalities in ventricular-vascular interaction due to increased myocardial and arterial stiffness. Galectin-3 is a recently discovered biomarker that plays an important role in myocardial and vascular fibrosis and heart failure progression. Objectives: The aim of this study was to determine whether galectin-3 is correlated with arterial stiffening markers and impaired ventricular-arterial coupling in decompensated heart failure patients. Methods: A total of 79 inpatients with acute decompensated heart failure were evaluated. Serum galectin-3 was determined at baseline, and during admission, transthoracic echocardiography and measurements of vascular indices by Doppler ultrasonography were performed. Results: Elevated pulse wave velocity and low arterial carotid distensibility are associated with heart failure in patients with preserved ejection fraction (p = 0.04, p = 0.009). Pulse wave velocity, carotid distensibility and Young’s modulus did not correlate with serum galectin-3 levels. Conversely, raised galectin-3 levels correlated with an increased ventricular-arterial coupling ratio (Ea/Elv) p = 0.047, OR = 1.9, 95% CI (1.0‑3.6). Increased galectin-3 levels were associated with lower rates of left ventricular pressure rise in early systole (dp/dt) (p=0.018) and raised pulmonary artery pressure (p = 0.046). High galectin-3 levels (p = 0.038, HR = 3.07) and arterial pulmonary pressure (p = 0.007, HR = 1.06) were found to be independent risk factors for all-cause mortality and readmissions. Conclusions: This study showed no significant correlation between serum galectin-3 levels and arterial stiffening markers. Instead, high galectin-3 levels predicted impaired ventricular-arterial coupling. Galectin-3 may be predictive of raised pulmonary artery pressures. Elevated galectin-3 levels correlate with severe systolic dysfunction and together with pulmonary hypertension are independent markers of outcome.


Resumo Fundamento: A insuficiência cardíaca é acompanhada por anormalidades na interação ventrículo-vascular devido à rigidez miocárdica e arterial aumentada. A galectina-3 é um biomarcador recentemente descoberto que exerce um importante papel na fibrose miocárdica e vascular, e na progressão da insuficiência cardíaca. Objetivos: O objetivo deste estudo foi determinar se a galectina-3 está correlacionada com marcadores de rigidez arterial e acoplamento ventriculoarterial deficiente em pacientes com insuficiência cardíaca descompensada. Métodos: Um total de 79 pacientes internados com insuficiência cardíaca descompensada foi avaliado. Galectina-3 sérica basal foi determinada e, durante a admissão hospitalar, foram realizadas ecocardiografia transtorácica e medidas de índices vasculares por ultrassonografia Doppler. Resultados: Velocidade de onda de pulso elevada e baixa distensibilidade da artéria carótida estão associadas com insuficiência cardíaca em pacientes com fração de ejeção preservada (p = 0,04, p = 0,009). Velocidade de pulso, distensibilidade da artéria carótida e módulo de Young não se correlacionaram com níveis séricos de galectina-3. Por outro lado, níveis elevados de galectina-3 correlacionaram com razão de acoplamento ventriculoarterial aumentada (Ea/Elv) p = 0,047, OR = 1,9, IC 95% (1,0-3,6). Níveis aumentados de galectina-3 estavam associados com taxas mais baixas de pressão ventricular esquerda na fase inicial da sístole (dp/dt) (p = 0,018), e pressão arterial pulmonar aumentada (p = 0,046). Os resultados mostraram que níveis elevados de galectina-3 (p = 0,038, HR = 3,07) e pressão pulmonar arterial (p = 0,007, HR = 1,06) são fatores de risco independentes para mortalidade de todas as causas e reinternações hospitalares. Conclusões: O estudo mostrou que não houve correlação significativa entre níveis séricos de galectina-3 e marcadores de rigidez arterial. Altos níveis de galectina-3, por outro lado, foi um preditor de acoplamento ventriculoarterial deficiente. A galectina-3 pode ser um preditor de pressões arteriais pulmonares aumentadas. Níveis elevados de galectina-3 correlacionam-se com disfunção sistólica grave e, juntamente com hipertensão pulmonar, é um marcador independente de desfecho.


Assuntos
Idoso , Humanos , Masculino , Pessoa de Meia-Idade , /sangue , Insuficiência Cardíaca/sangue , Insuficiência Cardíaca/fisiopatologia , Coração/fisiopatologia , Rigidez Vascular/fisiologia , Biomarcadores/sangue , Pressão Sanguínea/fisiologia , Espessura Intima-Media Carotídea , Ecocardiografia Doppler , Insuficiência Cardíaca , Hipertensão Pulmonar/sangue , Hipertensão Pulmonar/fisiopatologia , Valor Preditivo dos Testes , Análise de Onda de Pulso , Estatísticas não Paramétricas , Volume Sistólico/fisiologia , Remodelação Vascular/fisiologia , Disfunção Ventricular Esquerda/sangue , Disfunção Ventricular Esquerda/fisiopatologia
5.
Tex Heart Inst J ; 41(2): 179-83, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24808780

RESUMO

Apical akinesis and dilation in the absence of obstructive coronary artery disease is a typical feature of stress-induced (takotsubo) cardiomyopathy, whereas apical hypertrophy is seen in apical-variant hypertrophic cardiomyopathy. We report the cases of 2 patients who presented with takotsubo cardiomyopathy and were subsequently found to have apical-variant hypertrophic cardiomyopathy, after the apical ballooning from the takotsubo cardiomyopathy had resolved. The first patient, a 43-year-old woman with a history of alcohol abuse, presented with shortness of breath, electrocardiographic and echocardiographic features consistent with takotsubo cardiomyopathy, and no significant coronary artery disease. An echocardiogram 2 weeks later revealed a normal left ventricular ejection fraction and newly apparent apical hypertrophy. The 2nd patient, a 70-year-old woman with pancreatitis, presented with chest pain, apical akinesis, and a left ventricular ejection fraction of 0.39, consistent with takotsubo cardiomyopathy. One month later, her left ventricular ejection fraction was normal; however, hypertrophy of the left ventricular apex was newly noted. To our knowledge, these are the first reported cases in which apical-variant hypertrophic cardiomyopathy was masked by apical ballooning from stress-induced cardiomyopathy.


Assuntos
Antagonistas Adrenérgicos beta/administração & dosagem , Inibidores da Enzima Conversora de Angiotensina/administração & dosagem , Cardiomiopatia Hipertrófica , Cardiomiopatia de Takotsubo/diagnóstico , Adulto , Idoso , Alcoolismo/complicações , Cardiomiopatia Hipertrófica/diagnóstico , Cardiomiopatia Hipertrófica/tratamento farmacológico , Cardiomiopatia Hipertrófica/etiologia , Cardiomiopatia Hipertrófica/fisiopatologia , Diagnóstico Diferencial , Ecocardiografia/métodos , Feminino , Humanos , Pancreatite/complicações , Volume Sistólico , Resultado do Tratamento , Função Ventricular Esquerda
6.
Tex Heart Inst J ; 38(6): 621-6, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22199421

RESUMO

Studies have shown that long-term vagal stimulation is protective against ventricular fibrillation; however, the effects of acute vagal stimulation during ventricular fibrillation in the normal heart have not been investigated. We examined the effects of acute vagal stimulation on ventricular fibrillation in a canine model. In 4 dogs, we induced 30-second periods of ventricular fibrillation by means of intraventricular pacing. During 2 of the 4 periods of fibrillation that we analyzed, vagal stimulation was delivered through electrodes in the caudal ends of the vagus nerves. Noncontact unipolar electrograms were recorded from 3 ventricular regions: the basal septum, apical septum, and lateral free wall. We then computed the most frequent cycle length, mean organization index, and mean electrogram amplitude for each region. During fibrillation, vagal stimulation shortened the most frequent cycle lengths in the basal septum (P=0.02) and apical septum (P=0.0001), but not in the lateral wall (P=0.46). In addition, vagal stimulation significantly reduced the mean organization indices in the apical septum (P <0.001) and lateral wall (P <0.001), but not in the basal septum (P=0.19). Furthermore, vagal stimulation raised the mean electrogram amplitude in the basal septum (P <0.01) but lowered it substantially in the apical septum (P=0.00005) and lateral wall (P=0.00003). We conclude that vagal stimulation acutely affects the characteristics of ventricular fibrillation in canine myocardium in a spatially heterogeneous manner. This nonuniformity of response may have implications with regard to manipulating the autonomic system as a means of modifying the substrate for ventricular dysrhythmias.


Assuntos
Sistema de Condução Cardíaco/fisiopatologia , Estimulação do Nervo Vago , Fibrilação Ventricular/terapia , Função Ventricular Esquerda , Animais , Estimulação Cardíaca Artificial , Modelos Animais de Doenças , Cães , Técnicas Eletrofisiológicas Cardíacas , Análise de Fourier , Fatores de Tempo , Fibrilação Ventricular/etiologia , Fibrilação Ventricular/fisiopatologia
7.
Tex Heart Inst J ; 38(6): 627-38, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22199422

RESUMO

Heart-failure phenotypes include pulmonary and systemic venous congestion. Traditional heart-failure classification systems include the Forrester hemodynamic subsets, which use 2 indices: pulmonary capillary wedge pressure (PCWP) and cardiac index. We hypothesized that changes in PCWP and central venous pressure (CVP), and in the phenotypes of heart failure, might be better evaluated by cardiovascular modeling. Therefore, we developed a lumped-parameter cardiovascular model and analyzed forms of heart failure in which the right and left ventricles failed disproportionately (discordant ventricular failure) versus equally (concordant failure). At least 10 modeling analyses were carried out to the equilibrium state. Acute discordant pump failure was characterized by a "passive" volume movement, with fluid accumulation and pressure elevation in the circuit upstream of the failed pump. In biventricular failure, less volume was mobilized. These findings negate the prevalent teaching that pulmonary congestion in left ventricular failure results primarily from the "backing up" of elevated left ventricular filling pressure. They also reveal a limitation of the Forrester classification: that PCWP and cardiac index are not independent indices of circulation. Herein, we propose a system for classifying heart-failure phenotypes on the basis of discordant or concordant heart failure. A surrogate marker, PCWP-CVP separation, in a simplified situation without complex valvular or pulmonary disease, shows that discordant left and right ventricular failures are characterized by differences of ≥ 4 and ≤ 0 mmHg, respectively. We validated the proposed model and classification system by using published data on patients with acute and chronic heart failure.


Assuntos
Pressão Venosa Central , Insuficiência Cardíaca/classificação , Insuficiência Cardíaca/fisiopatologia , Modelos Cardiovasculares , Pressão Propulsora Pulmonar , Doença Aguda , Animais , Débito Cardíaco , Doença Crônica , Insuficiência Cardíaca/diagnóstico , Humanos , Fenótipo , Prognóstico , Circulação Pulmonar , Reprodutibilidade dos Testes , Função Ventricular Esquerda , Função Ventricular Direita , Pressão Ventricular
8.
Tex Heart Inst J ; 38(4): 418-20, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21841873

RESUMO

Left ventricular reconstruction is advocated as a surgical option for patients with severe congestive heart failure. Despite initial enthusiasm for this procedure, reports of long-term results are sparse. Herein, we describe a particularly gratifying case of left ventricular reconstruction in a 43-year-old man, who continues to have excellent left ventricular function 10 years postoperatively. This approach may be a reasonable alternative to cardiac transplantation in patients who lack other treatment options.


Assuntos
Procedimentos Cirúrgicos Cardíacos , Insuficiência Cardíaca/cirurgia , Ventrículos do Coração/cirurgia , Disfunção Ventricular Esquerda/cirurgia , Ecocardiografia , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/fisiopatologia , Ventrículos do Coração/fisiopatologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Recuperação de Função Fisiológica , Índice de Gravidade de Doença , Volume Sistólico , Fatores de Tempo , Resultado do Tratamento , Disfunção Ventricular Esquerda/diagnóstico , Disfunção Ventricular Esquerda/fisiopatologia , Função Ventricular Esquerda
9.
Tex Heart Inst J ; 38(1): 50-1, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21423468

RESUMO

The direct measurement of left ventricular pressure in the presence of a mechanical aortic valve is a technical challenge for the interventional cardiologist. Direct recording, which is rarely performed, becomes necessary when other imaging methods have failed to evaluate prosthetic valve stenosis or restrictive physiology. Left ventricular pressure has typically been measured after transseptal or direct left ventricular apical puncture.In recent years, investigators have used the 0.014-in coronary Radi PressureWire™ (St. Jude Medical, Inc.; St. Paul, Minn) to cross the St. Jude bileaflet prosthetic aortic valve without the need for puncture. Although another bileaflet aortic valve, the ATS Open Pivot® (ATS Medical, Inc.; Minneapolis, Minn), has an overall design similar to that of the St. Jude valve, the ATS valve has an open-pivot hinge, which has the potential for wire entrapment.Herein, we describe how we successfully measured left ventricular pressure by crossing an ATS Open Pivot prosthetic valve with a Radi PressureWire, in a 60-year-old man in whom pericardial constriction was suspected. The straightforward, uncomplicated procedure enabled confirmation of the diagnosis. We believe that further investigation of this technique is warranted.


Assuntos
Valva Aórtica/cirurgia , Cateterismo Cardíaco/instrumentação , Implante de Prótese de Valva Cardíaca/instrumentação , Próteses Valvulares Cardíacas , Pericardite Constritiva/diagnóstico , Função Ventricular Esquerda , Pressão Ventricular , Idoso , Desenho de Equipamento , Humanos , Masculino , Pericardite Constritiva/fisiopatologia , Valor Preditivo dos Testes , Desenho de Prótese
10.
Tex Heart Inst J ; 37(4): 483-5, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20844629

RESUMO

The diagnosis of Wolff-Parkinson-White syndrome is typically reserved for patients who experience ventricular pre-excitation and symptoms that are related to paroxysmal supraventricular tachycardia, such as chest pain, dyspnea, dizziness, palpitations, or syncope. Herein, we report the case of a 38-year-old woman who presented at our outpatient department because of exercise intolerance. Cardiac auscultation revealed a grade 2/6 pansystolic murmur over the left lower sternal border. Twelve-lead electrocardiography showed sinus rhythm at a rate of 76 beats/min, with a significant delta wave. Transthoracic echocardiography revealed abnormal left ventricular systolic function. The results of a thallium stress test were also abnormal. Coronary artery disease was suspected; however, coronary angiography yielded normal results. Electrophysiologic study revealed a para-Hisian Kent bundle and a dual atrioventricular nodal pathway. After radiofrequency catheter ablation was performed, the patient's left ventricular function improved and her symptoms disappeared. In Wolff-Parkinson-White syndrome, left ventricular systolic dyssynchrony can yield abnormal findings on echocardiography and thallium scanning--even in persons who have no cardiovascular risk factors. Physicians who are armed with this knowledge can avoid performing coronary angiography unnecessarily. Catheter ablation can reverse the dyssynchrony of the ventricle and improve the patient's symptoms.


Assuntos
Feixe Acessório Atrioventricular/fisiopatologia , Ablação por Cateter , Teste de Esforço , Disfunção Ventricular Esquerda/cirurgia , Função Ventricular Esquerda , Síndrome de Wolff-Parkinson-White/cirurgia , Adulto , Ecocardiografia , Eletrocardiografia , Técnicas Eletrofisiológicas Cardíacas , Tolerância ao Exercício , Feminino , Auscultação Cardíaca , Humanos , Volume Sistólico , Sístole , Resultado do Tratamento , Disfunção Ventricular Esquerda/etiologia , Disfunção Ventricular Esquerda/fisiopatologia , Síndrome de Wolff-Parkinson-White/complicações , Síndrome de Wolff-Parkinson-White/diagnóstico , Síndrome de Wolff-Parkinson-White/fisiopatologia
11.
Tex Heart Inst J ; 37(1): 88-91, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20200635

RESUMO

Several cases of inverted Takotsubo cardiomyopathy--a variant form with hyperdynamic left ventricular apex and akinesia of the left ventricular base and mid-portion--have been reported recently, especially in association with cerebrovascular accidents and catecholamine cardiomyopathies. Herein, we describe 2 cases of inverted Takotsubo cardiomyopathy: one that occurred in a middle-aged woman who had a septic condition, and another in a young woman who was in the postpartal state. Such cases have not been reported previously.


Assuntos
Transtornos Puerperais/etiologia , Sepse/complicações , Cardiomiopatia de Takotsubo/etiologia , Adulto , Antibacterianos/uso terapêutico , Fármacos Cardiovasculares/uso terapêutico , Angiografia Coronária , Quimioterapia Combinada , Ecocardiografia , Feminino , Hemodinâmica , Humanos , Balão Intra-Aórtico , Período Pós-Parto , Gravidez , Transtornos Puerperais/diagnóstico , Transtornos Puerperais/fisiopatologia , Transtornos Puerperais/terapia , Sepse/fisiopatologia , Sepse/terapia , Cardiomiopatia de Takotsubo/diagnóstico , Cardiomiopatia de Takotsubo/fisiopatologia , Cardiomiopatia de Takotsubo/terapia , Resultado do Tratamento
12.
Tex Heart Inst J ; 35(1): 73-5, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18427659

RESUMO

Takotsubo cardiomyopathy, or transient apical ballooning syndrome, is a recently recognized form of transient left ventricular dysfunction that is presumably caused by stress. Takotsubo cardiomyopathy can clinically resemble an acute coronary syndrome. Reported cases have been preceded by emotional stress or medical illness. Herein, we report a fatal case of takotsubo cardiomyopathy that followed a dobutamine stress test. We believe that the dobutamine infusion led to stress-induced cardiomyopathy with a dynamic left ventricular outflow tract obstruction. To our knowledge, there is only 1 other report of an association between dobutamine infusion and the development of takotsubo cardiomyopathy.


Assuntos
Ecocardiografia sob Estresse/efeitos adversos , Cardiomiopatia de Takotsubo/etiologia , Obstrução do Fluxo Ventricular Externo/etiologia , Idoso de 80 Anos ou mais , Feminino , Humanos , Cardiomiopatia de Takotsubo/complicações , Cardiomiopatia de Takotsubo/diagnóstico por imagem , Resultado do Tratamento
13.
São Paulo; s.n; 2006. 102 p. ilus, tab.
Tese em Português | LILACS | ID: lil-587112

RESUMO

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...


Assuntos
Animais , Cobaias , Cabras , Ventrículos do Coração , Hipertrofia Ventricular Direita , Hipertrofia/fisiopatologia , Procedimentos Cirúrgicos Cardíacos/métodos , Transposição dos Grandes Vasos/cirurgia
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