RESUMO
OBJECTIVES: We sought to evaluate dobutamine stress echocardiography (DSE) for predicting recovery of viable myocardium after revascularization with cineangiography as a gold standard for left ventricular (LV) function. We studied the influence of late vessel reocclusion on regional LV function. BACKGROUND: Dobutamine stress echocardiography is a well established evaluation method for myocardial viability assessment. In previous studies the reference method for assessing LV recovery was echocardiography, long-term vessel patency has not been systematically addressed. METHODS: Sixty-eight patients with a first acute myocardial infarction (AMI) and residual stenosis of the infarct related artery (IRA) underwent DSE (mean +/- standard deviation) 21 +/- 12 days after AMI to evaluate myocardial viability. Revascularization of the IRA was performed in 54 patients by angioplasty (n = 43) or bypass grafting (n = 11). Coronary angiography and LV cineangiography were repeated at four months to assess LV function and IRA patency. RESULTS: Sensitivity and specificity of DSE for predicting myocardial recovery after revascularization were 83% and 82%. In the case of late IRA patency, specificity increased to 95%, whereas sensitivity remained unchanged. In the 16 patients with myocardial viability and late IRA patency, echocardiographic wall motion score index decreased after revascularization from 1.83 +/- 0.15 to 1.36 +/- 0.17 (p = 0.0001), and left ventricular ejection fraction (LVEF) increased from 0.52 +/- 0.06 to 0.57 +/- 0.06 (p = 0.0004), whereas in five patients, reocclusion of the IRA prevented improvement of segmental or global LV function despite initially viable myocardium. CONCLUSIONS: Dobutamine stress echocardiography is reliable to predict recovery of viable myocardium after revascularization in postinfarction patients. Late reocclusion of the IRA may prevent LV recovery and influence the accuracy of DSE.
Assuntos
Angioplastia Coronária com Balão , Ponte de Artéria Coronária , Contração Miocárdica/fisiologia , Infarto do Miocárdio/terapia , Função Ventricular Esquerda/fisiologia , Adulto , Idoso , Cardiotônicos , Cineangiografia , Angiografia Coronária , Dobutamina , Ecocardiografia , Teste de Esforço , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/fisiopatologia , Variações Dependentes do Observador , Sensibilidade e Especificidade , Sobrevivência de Tecidos/fisiologiaRESUMO
Background--Currently, the reporting and archiving of echocardiographic data suffer from the difficulty of representing heart motion on printable 2-dimensional (2D) media. Methods and Results--We studied the capability of holography to integrate motion into 2D echocardiographic prints. Images of normal human hearts and of a variety of mitral valve function abnormalities (mitral valve prolapse, systolic anterior motion of the mitral leaflets, and obstruction of the mitral valve by a myxoma) were acquired digitally on standard echocardiographic machines. Images were processed into a data format suitable for holographic printing. Angularly multiplexed holograms were then printed on a prototype holographic "laser" printer, with integration of time in vertical parallax, so that heart motion became visible when the hologram was tilted up and down. The resulting holograms displayed the anatomy with the same resolution as the original acquisition and allowed detailed study of valve motion with side-by-side comparison of normal and abnormal findings. Comparison of standard echocardiographic measurements in original echo frames and corresponding hologram views showed an excellent correlation of both methods (P<0.0001, r2=0.979, mean bias=2.76 mm). In this feasibility study, both 2D and 3D holographic images were produced. The equipment needed to view these holograms consists of only a simple point-light source. Conclusions--Holographic representation of myocardial and valve motion from echocardiographic data is feasible and allows the printing on a 2D medium of the complete heart cycle. Combined with the recent development of online holographic printing, this novel technique has the potential to improve reporting, visualization, and archiving of echocardiographic imaging.
RESUMO
Cigarette smoking increases the alveolar epithelial permeability to small solutes, as assessed by the pulmonary clearance of aerosolized 99mTc-labeled diethylenetriaminepentaacetate. The involvement of lipid peroxidation in this increased clearance was tested in eight asymptomatic young smokers by investigating the effects of a 3-wk supplementation with oral vitamin E (1,000 IU/day) on pulmonary clearance according to a protocol designed as a single-blind crossover study. Indexes of acute tobacco intoxication (exhaled CO, carboxyhemoglobin, and urinary cotinine) and lung function parameters [including Krogh factor (KCO)] were also studied. Under control conditions, pulmonary clearance was abnormally increased (2.93 +/- 0.78%/min), whereas KCO was in the normal range. Pulmonary clearance correlated strongly with expired CO (P < 0.04), HbCO (P < 0.005), urinary cotinine (P < 0.003), and KCO (P < 0.004). Supplementation with vitamin E, a highly efficient antioxidant, neither decreased the pulmonary clearance nor altered the above correlations. However, the strong correlations observed between pulmonary clearance and indexes of acute tobacco intoxication, which reflect the amount of inhaled smoke and the resultant oxidant stress, do not allow exclusion of the involvement of lipid peroxidation in the pulmonary clearance increase observed in smokers.
Assuntos
Pulmão/efeitos dos fármacos , Nicotina/toxicidade , Sistema Respiratório/efeitos dos fármacos , Fumar , Vitamina E/farmacologia , Adulto , Creatinina/urina , Feminino , Humanos , Masculino , Testes de Função RespiratóriaRESUMO
Stable angina is usually due to coronary atherosclerosis and complicated by myocardial lesions responsible for ischaemic myocardiopathy. Tobacco suppression, aspirin and cholesterol lowering drugs especially statins are the best way to slow coronary atherosclerosis progression. beta-blockers, physical conditioning are the two main medical means to suppress anginal symptoms. Converting enzyme inhibitors and beta-blockers are useful to slow the progression rate of ischaemic cardiomyopathy. Revascularisation procedures are combined with medical treatment and help treating symptoms and preventing myocardial lesions.