Este relato apresenta o seguimento tardio de um caso de cardiomiopatia de Takotsubo com boa evolução clínica e melhora da função sistólica global ventricular esquerda. Contudo, observou-se persistência de significativa disfunção sistólica regional longitudinal que foi avaliada por meio de nova técnica ecocardiográfica (speckle tracking), com as medidas do strain (S) e strain rate (SR) correspondentes. Ressaltamos a importância desse novo método para o acompanhamento dessa cardiopatia, pois permite identificar os pacientes que persistem com disfunção sistólica e que possivelmente serão beneficiados com a manutenção da terapêutica clínica.
Strain bidimensional na cardiopatia de Takotsubo
Clínica Medicar - Hospital São Carlos, Fortaleza, CE - Brasil
Este relato apresenta o seguimento tardio de um caso de cardiomiopatia de Takotsubo com boa evolução clínica e melhora da função sistólica global ventricular esquerda. Contudo, observou-se persistência de significativa disfunção sistólica regional longitudinal que foi avaliada por meio de nova técnica ecocardiográfica (
A cardiomiopatia estresse-induzida, também conhecida como cardiomiopatia de Takotsubo, é uma síndrome caracterizada por uma disfunção ventricular esquerda segmentar que acomete principalmente a região apical1. Ela é desencadeada por diversos fatores, como estresse emocional ou psicológico2, cirurgias de grande porte e doenças sistêmicas graves. Apresenta-se com quadro clínico variável, desde dor torácica e dispneia até choque cardiogênico, com alterações eletrocardiográficas e elevação de marcadores de necrose miocárdica, sem, contudo, haver doença coronariana significativa à angiografia. Caracteriza-se pela resolução rápida do quadro, com melhora da função ventricular e, na maioria das vezes, completa recuperação da discinesia ventricular esquerda, com prognóstico muito bom3. Novos métodos ecocardiográficos têm sido aplicados na avaliação da contratilidade miocárdica regional, com destaque para o
Trata-se de paciente de 55 anos, hipertensa, com exames pré-operatórios normais, incluindo eletrocardiograma (ECG), ecocardiograma (ECO) e cintilografia de perfusão miocárdica, submetida a colecistectomia e colangiografia videolaparoscópica, com anestesia geral. A cirurgia transcorreu bem, e, na sala de recuperação, a paciente apresentou quadro de edema agudo de pulmão e instabilidade hemodinâmica significativa, necessitando de suporte com drogas vasoativas.
O ECG realizado mostrou taquicardia sinusal sem alterações isquêmicas agudas. A radiografia de tórax mostrou importante congestão venocapilar pulmonar. O ecocardiograma à beira do leito mostrou cavidades cardíacas com dimensões normais, com acinesia das paredes septal anterior, apical, anteroapical e inferoapical do ventrículo esquerdo (VE), disfunção sistólica global grave (fração de ejeção = 30% pelo método de Simpson) do VE, com sinais indiretos de hipertensão arterial pulmonar (pressão sistólica arterial pulmonar = 58 mmHg). Enzimas cardíacas estavam elevadas (CPK = 3.019/CKMB, massa = 90,4/troponina I = 2,46). Com esse quadro, aventou-se a possibilidade de doença arterial coronariana (DAC), e a paciente foi submetida a cineangiocoronariografia, que não revelou lesões coronarianas. A ventriculografia mostrou acinesia apical e anterior, com contratilidade basal preservada, o que caracteriza a forma clássica da cardiomiopatia induzida por estresse ou síndrome de Takotsubo.
A paciente permaneceu internada na UTI, evoluindo com melhora clínica progressiva. Recebeu alta hospitalar, e, após uma semana, realizamos novo ecocardiograma que mostrou melhora parcial da contratilidade do VE, ainda persistindo hipocinesia apical, porém com FE calculada em 59% e com disfunção diastólica estágio I do VE. Novo ecocardiograma realizado 15 dias após o quadro mostrou completa resolução da discinesia segmentar, com total recuperação da contratilidade global do VE (FE = 76% Teichholz e 70% Simpson), além de pressões pulmonares normais.
A paciente encontra-se clinicamente bem, em uso de inibidor da enzima conversora da angiotensina (ECA) e betabloqueador, tendo retornado recentemente ao serviço para realização de ecocardiograma de controle, após 20 meses do evento descrito, o qual mostrou contratilidade global e segmentar do VE normais (FE = 72% Teichholz e 69% Simpson), além de função diastólica normal (relação E/A = 1,23, E/E' = 9). Pela análise
A cardiomiopatia de Takotsubo caracteriza-se tradicionalmente pela completa resolução da disfunção ventricular4,5, com melhora dos parâmetros ecocardiográficos, com destaque para a melhora da análise subjetiva da contratilidade segmentar e da função sistólica global. A ecocardiografia exerce papel fundamental no diagnóstico, pois identifica as alterações segmentares da contratilidade e outros achados possíveis, como obstrução na via de saída do VE, insuficiência valvar mitral e disfunção diastólica associada. Esse exame também quantifica a função sistólica global do VE. Além disso, permite realizar o acompanhamento da função ventricular, identificando a completa resolução das alterações em período curto de tempo. Porém, a ecocardiografia convencional apresenta a limitação de avaliar apenas a contratilidade no seu sentido radial. É de amplo conhecimento a complexa disposição geométrica das fibras miocárdicas que determina mecanismos sistólicos em várias direções: radial (espessamento), longitudinal (encurtamento) e circunferencial (torsão).
Novas técnicas ecocardiográficas têm surgido nos últimos anos, o que possibilita a avaliação da contratilidade regional por meio de métodos quantitativos. Entre elas, destaca-se o
O
Poucos relatos têm aplicado esse método a essa importante entidade, cada vez mais diagnosticada em nosso meio. Habitualmente, ocorre completa resolução da disfunção sistólica em um período de 2 a 4 semanas do evento inicial, com melhora da fração de ejeção ventricular8. Burri e cols.9 acompanharam alguns pacientes com essa cardiomiopatia e demonstraram, por meio dessa nova modalidade, uma importante redução na função sistólica regional, com uma melhora significativa ao longo do tempo.
O presente caso abordou a aplicação do
Declaro não haver conflito de interesses pertinentes.
O presente estudo não teve fontes de financiamento externas.
Não há vinculação deste estudo a programas de pós-graduação.
Correspondência: Carlos Bellini G. Gomes Rua Dr. José Lourenço, 938 - Meireles 60160-110 - Fortaleza, CE -Brasil E-mail:
Artigo recebido em 28/06/09; revisado recebido em 11/09/09; aceito em 23/12/09.
This report presents the late follow-up of a case of Takotsubo cardiomyopathy with good clinical outcome and improved left ventricular global systolic function. However, there was persistence of significant regional longitudinal systolic dysfunction evaluated using a new echocardiographic technique (speckle tracking), with corresponding measures of strain (S) and strain rate (SR). We emphasize the importance of this new method to monitoring this cardiomyopathy, since it identifies patients with persistent systolic dysfunction who will possibly benefit from maintenance of clinical therapy
Clínica Medicar - Hospital São Carlos, Fortaleza, CE - Brazil
Mailing address
This report presents the late follow-up of a case of Takotsubo cardiomyopathy with good clinical outcome and improved left ventricular global systolic function. However, there was persistence of significant regional longitudinal systolic dysfunction evaluated using a new echocardiographic technique (speckle tracking), with corresponding measures of strain (S) and strain rate (SR). We emphasize the importance of this new method to monitoring this cardiomyopathy, since it identifies patients with persistent systolic dysfunction who will possibly benefit from maintenance of clinical therapy.
The stress-induced cardiomyopathy, also known as Takotsubo cardiomyopathy, is a syndrome characterized by a segmental left ventricular dysfunction that affects mainly the apical region1. It is triggered by several factors such as emotional or psychological stress2, major surgeries and severe systemic diseases. It presents a variable clinical picture ranging from chest pain and dyspnea to cardiogenic shock with ECG changes and elevation of myocardial necrosis markers, with no significant coronary disease at angiography, though. It is characterized by the rapid resolution of the picture, with improved ventricular function and, in most cases, complete recovery of left ventricular dyssynergy, with very good prognosis3. New echocardiographic methods have been applied in the evaluation of regional myocardial contractility, especially the two-dimensional strain. We report a case in which this new echocardiographic tool was used to further scrutinize ventricular function in late follow-up.
A 55-year-old hypertensive woman with normal preoperative exams, including electrocardiogram (ECG), echocardiogram (ECHO) and myocardial perfusion scintigraphy underwent laparoscopic cholecystectomy and cholangiography under general anesthesia. The surgery went well, and in the recovery room, the patient developed acute pulmonary edema and significant hemodynamic instability, requiring support with vasoactive drugs.
ECG showed sinus tachycardia without acute ischemic changes. Chest radiography revealed severe pulmonary venous congestion. Bedside echocardiogram showed cardiac chambers with normal dimensions, akinesia of left ventricular (LV) septal anterior, apical, anteroapical and inferoapical walls, severe LV systolic dysfunction (ejection fraction = 30% by the Simpson method), indirect signs of pulmonary arterial hypertension (systolic pulmonary artery pressure = 58 mmHg). Cardiac enzymes were high (CPK = 3,019/CKMB, mass = 90.4/troponin I = 2.46). This picture suggested the possibility of coronary artery disease (CAD), and the patient underwent coronary angiography, which revealed no coronary lesions. Ventriculography showed apical and anterior akinesia, with preserved basal contractility, which characterizes the classic form of stress-induced cardiomyopathy or Takotsubo syndrome.
The patient was admitted to the ICU, with progressive clinical improvement. She was discharged, and after one week, we performed a new echocardiogram that showed partial improvement of LV contractility. Apical hypokinesia persisted, but with an EF estimated at 59% and stage I LV diastolic dysfunction. Another echocardiogram was performed 15 days after the picture has shown complete resolution of segmental dyssynergy, with full recovery of global LV contractility (EF = 76% Teichholz and 70% Simpson), and normal pulmonary pressures, as well.
The patient was clinically well, under use of angiotensin-converting enzyme (ACE) [Check my insertion] and beta-blockers. She had recently returned to the clinic for echocardiography after 20 months of the event described. ECG revealed normal global and segmental LV contractility (EF = 72% Teicholz and 69% Simpson), as well as normal diastolic function (E/A ratio = 1.23, E/E'= 9). Considering the offline analysis of two-dimensional images obtained (apical sections of 4, 3 and 2 chambers), we could assess the LV regional systolic function, with the measures of longitudinal myocardial strain (S) in various segments, as shown in
Takotsubo cardiomyopathy is traditionally characterized by the complete resolution of ventricular dysfunction4,5, with improvement in echocardiographic parameters, especially an improved subjective analysis of segmental contractility and global systolic function. Echocardiography plays a key role in diagnosis, since it identifies segmental contractility alterations and other possible findings, such as obstruction in LV outflow tract, mitral valve failure and associated diastolic dysfunction. This examination also quantifies the LV global systolic function. Moreover, it allows following up ventricular function, identifying the complete resolution of changes in a short period. However, conventional echocardiography has the limitation of assessing only the contractility in its radial direction. The complex geometric arrangement of the myocardial fibers is widely known. It determines systolic mechanisms in several directions: radial (thickness), longitudinal (shortening) and circumferential (torsion).
New echocardiographic techniques have emerged in recent years, enabling the assessment of regional contractility through quantitative methods. These techniques include the two-dimensional strain through the speckle tracking method.
The two-dimensional strain is a new ultrasound method used to measure the strain and myocardial strain rate6. It assesses motility by measuring the displacement of several acoustic points (speckles) naturally present in different interfaces of the myocardium, in a conventional two-dimensional image. Each point in a given region is followed over several frames throughout the cardiac cycle. These points are then tracked, and by means of calculations performed by specific software applications, the image is spatially and temporally processed, whereby these elements are recognized and selected6. The individual displacement of each point (speckle) represents the local tissue movement. By tracking these points, strain and strain rate are measured after a careful automatic analysis of the image quality. The diagnostic information of each trace is presented in a colored parametric form (combination of colors to data digitally collected), representing different quantitative indices of myocardial contractility. Thus, normal peak systolic strain is shown in red, dyskinetic areas or with very low systolic strain in dark blue, for example. Longitudinal and circumferential strains showed negative curves representing systolic shortening, while radial strain is positive. The following are considered normal values of longitudinal peak systolic strain: -20 to -22% (+/- 2.2%)7.
Few reports have applied this method to this important entity, increasingly diagnosed in our country. There is usually a complete resolution of systolic dysfunction in a period of 2 to 4 weeks from the initial event, with improvement in left ventricular ejection fraction8. Burri et al9 monitored some patients with this cardiomyopathy and demonstrated through this new technique a significant reduction in regional systolic function, with a significant improvement over time.
This case addressed the application of two-dimensional strain in Takotsubo cardiomyopathy, and identified significant changes in regional contractility even after a follow-up period. A number of questions were raised about this method in treating this cardiomiopathy, such as the possibility of being a partially reversible disease, rather than the traditional definition of its complete resolution. Hence, the longitudinal two-dimensional strain technique was useful in monitoring affected patients, since it is able to identify those that evolve with continuing changes in contractility and possibly require permanent treatment and careful follow-up.
No potential conflict of interest relevant to this article was reported.
There were no external funding sources for this study.
This study is not associated with any post-graduation program.