Júlio Botas

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BACKGROUND Myocardial reperfusion is associated with calcium overload and cell contracture, mechanisms that may precipitate cell death. In this study, we tested the hypothesis that in vivo inhibition of this contracture could lead to cell preservation in an open-chest large animal model. METHODS AND RESULTS Regional myocardium function was measured during(More)
BACKGROUND Transplant vasculopathy (TxCAD) limits longterm survival of allograft recipients. The possibility that preexistent donor coronary disease (PEDD) might accelerate this process is of concern. The serial progression of sites with and without PEDD as assessed by intravascular ultrasonic imaging is explored in this study. METHODS AND RESULTS Thirty(More)
OBJECTIVES The purpose of this study was to quantify the severity of transplant coronary artery disease and to assess lesion characteristics early and up to 15 years after heart transplantation by using intracoronary ultrasound. BACKGROUND Intravascular ultrasound has the ability to measure the components of the arterial wall and has been shown to be a(More)
OBJECTIVES Our purpose was to study whether the in-hospital prognosis of anterior acute myocardial infarction (AMI) is influenced by preexistent collateral circulation to the infarct-related artery. BACKGROUND Collateral circulation exerts beneficial influences on the clinical course after AMI, but demonstration of improved survival is lacking. METHODS(More)
BACKGROUND Compensatory enlargement of the vessel wall has been described in the early stages of native atherosclerosis. Whether compensatory enlargement plays a role in transplant coronary artery disease is not known. The objective of this study was to determine, by use of serial intravascular ultrasound (IVUS), whether compensatory dilation occurs in(More)
BACKGROUND Coronary endothelial vasodilator dysfunction is a common finding in cardiac transplant recipients and may represent an early marker for the development of intimal thickening and graft atherosclerosis. The present study tested the hypothesis that endothelial dysfunction precedes intimal thickening and that administration of L-arginine, the(More)
OBJECTIVES This study compares the efficacy of primary angioplasty and systemic thrombolysis with t-PA in reducing the in-hospital mortality of patients with anterior AMI. BACKGROUND Controversy still exists about the relative benefit of primary angioplasty over thrombolysis as treatment for AMI. METHODS Two-hundred and twenty patients with anterior AMI(More)
Myocardial water content and infarct size were studied in 39 pigs randomly assigned to a nonintervention group, a group with an intracoronary infusion of a control solution, and a group with a hyperosmotic infusion to 450 mosM by the addition of D-mannitol. The intracoronary solutions were selectively infused into the left anterior descending coronary(More)
BACKGROUND Intravascular ultrasound (IVUS) studies have demonstrated that stents are frequently suboptimally expanded despite the use of high pressures for deployment. The purpose of this study was to identify the mechanisms responsible for such residual lumen stenosis. METHODS AND RESULTS Fifty-seven lesions from 50 patients treated with high-pressure(More)
Quantification of intramyocardial hemorrhage was performed in 69 pigs submitted to various protocols of coronary artery occlusion and reperfusion. The study groups include 1) permanent occlusion; 2) reperfusion after periods of coronary occlusion of 30, 45, 60, 90, and 120 minutes; 3) reperfusion with diltiazem and with 4) methoxamine after a 60-minute(More)