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Biomedical subjects

V C Lima

Publications and source records attributed to V C Lima.

15 recordsLinked to original sources
PubMed2003

Safety and efficacy of sirolimus in kidney transplant patients and in patients with coronary artery disease undergoing angioplasty.

UNLABELLED: We show the key results of our 4-year experience with sirolimus in kidney transplant patients and in nontransplanted patients undergoing coronary angioplasty. METHODS: Recipients of one-haplotype living-related kidney allografts were randomized to receive sirolimus (2 mg/d, n = 35) or azathioprine (2 mg/kg per day, n = 35). Recipients of fully mismatched living kidney allografts (n = 55) received sirolimus (2 mg/day). High-risk recipients of black ethnicity (n = 68) were randomized to target whole-blood trough sirolimus concentrations between 8 and 12 ng/mL or 15 to 20 ng/mL. All kidney transplant patients received cyclosporine and prednisone. Sirolimus/cyclosporine pharmacokinetic studies were performed in 40 patients receiving 2 mg (n = 20) or 5 mg (n = 20) of sirolimus 7 days after transplantation. In the coronary intervention study, 12 patients at high risk for in-stent restenosis received sirolimus for 28 days after angioplasty. RESULTS: The incidence of biopsy-confirmed acute rejection was 11.4% in recipients of one-haplotype living-related kidney allografts, 16.4% in recipients of fully mismatched living kidney allografts, and 15% (8 to 12 ng/mL) and 4% (15 to 20 ng/mL) in high-risk recipients of black ethnicity. Cyclosporine exposure was higher after morning administration compared to evening administration. There were poor correlations between sirolimus and cyclosporine exposures. The 4-month follow-up angiography revealed no restenosis (stenosis diameter > 50%), a late loss of 0.56 +/- 0.40 mm, and a loss index of 0.33 +/- 0.30. The follow-up 3D-intravascular ultrasound restudy showed an in-stent relative volumetric obstruction of 9.9 +/- 5.5%. Sirolimus in highly effective in preventing kidney allograft acute rejection and in-stent coronary restenosis.

Adult↗
PubMed2000

Influence of autonomic neuropathy upon left ventricular dysfunction in insulin-dependent diabetic patients.

BACKGROUND: Diabetic cardiomyopathy is a well-defined complication of diabetes that occurs in the absence of ischemic, vascular, and hypertensive disease. HYPOTHESIS: The study was undertaken to test the relationship among autonomic neuropathy (AN), 24-h blood pressure (BP) profile, and left ventricular function. METHODS: Nineteen type-1 diabetic patients underwent autonomic tests and echocardiographic examination. Patients were divided according to the presence (AN+) or absence (AN-) of AN. RESULTS: In the AN+ group (n = 8), the E/A ratio at echo was lower than in the AN- group (n = 11) (1.1 +/- 0.3 vs. 1.6 +/- 0.3; p < 0.005). Systolic and diastolic BP reductions during sleep were smaller in the AN+ than in the AN- group (6.6 +/- 6.6 vs. 13.0 +/- 4.3%; p < 0.03 for systolic and 12.8 +/- 6.8 vs. 20.0 +/- 4.0% for diastolic BP reduction; p < 0.03, respectively). Considering all patients, the E/A ratio correlated inversely with awake diastolic BP (r - 0.63; p = 0.005); sleep systolic BP (r - 0.48; p = 0.04), and sleep diastolic BP (r - 0.67; p = 0.002). The AN correlated with diastolic interventricular septum thickness (r 0.57; p = 0.01), sleep systolic BP (r 0.45; p = 0.05), sleep diastolic BP (r 0.54; p = 0.02), and correlated inversely with systolic and diastolic sleep BP reduction (r - 0.49; p = 0.03 and r - 0.67; p = 0.002, respectively). Finally, E/A ratio and AN score correlated between themselves (r - 0.6; p = 0.005). CONCLUSION: Our results suggest that left ventricular diastolic dysfunction may be detected very early in type-1 diabetic patients with AN. Parasympathetic lesion and nocturnal elevations in BP could be the link between AN and diastolic ventricular dysfunction.

Adult↗
PubMed2000

Non-invasive determination of the systolic peak-to-peak gradient in children with aortic stenosis: validation of a mathematical model.

Doppler derived systolic pressure gradients have become widely applied as noninvasively obtained estimates of the severity of aortic valvar stenosis. There is little correlation, however, between the Doppler derived peak instantaneous gradient and the peak-to-peak gradient obtained at catheterisation, the latter being the most applied variable to determine severity in children. The purpose of this study was to validate a mathematical model based on data from catheterisation which estimates the peak-to-peak gradient from variables which can be obtained by noninvasive means (Doppler derived mean gradient and pulse pressure), according to the formula: peak-to-peak systolic gradient = 6.02+/-1.49*(mean gradient)-0.44*(pulse pressure). Simultaneous cardiac catheterization and Doppler studies were performed on 10 patients with congenital aortic valvar stenosis. Correlations between the gradients measured at catheter measured, and those derived by Doppler, were performed using linear regression analysis. The mean gradients correlated well (y = 0.67 x +11.11, r = 0.87, SEE = 6 mm Hg, p = 0.001). The gradients predicted by the formula also correlated well with the peak-to-peak gradients measured at catheter (y = 0.66 x +14.44, r = 0.84, SEE = 9 mm Hg, p = 0.002). The data support the application of the model, allowing noninvasive prediction of the peak-to-peak gradient across the aortic valvar stenosis.

Adolescent↗
PubMed1999

Long-term endothelial dysfunction after coronary artery stenting.

OBJECTIVES: We assessed the endothelial-dependent vasomotor function in nonrestenotic coronary arteries more than six months following stent implantation, balloon angioplasty (BA), and directional atherectomy (DCA). BACKGROUND: Catheter-based coronary interventions are associated with extensive arterial injury. Endothelial function has been shown to remain chronically abnormal after vascular injury. The long-term effects of different percutaneous coronary interventions on endothelial function are not known. METHODS: Thirty-nine patients treated at least six months earlier with a coronary intervention for isolated proximal left anterior descending (LAD) stenosis, with no evidence of restenosis, were studied. Twelve patients had been stented, 15 had been treated with BA, and 12 had undergone DCA. Changes in diameter of the intervened LAD, and the unintervened circumflex coronary artery (Cx), in response to intracoronary acetylcholine infusions were assessed by quantitative angiography. RESULTS: The groups had similar angiographic characteristics and risk factors for endothelial dysfunction. The LAD constricted significantly more (p = 0.02) in previously stented patients (-21.8+/-4.3%), as compared to patients previously treated with BA (-9.5+/-2.8%) or with DCA (-9.1+/-3.6%). In contrast, acetylcholine infusion resulted in mild constriction in the Cx, which was similar in the three groups (p = 0.47). By multiple regression analysis, previous implant of a stent was the only significant predictor of LAD constriction (p = 0.008). CONCLUSIONS: More severe endothelial dysfunction was observed long term after stenting as compared to BA or DCA. These findings may have implications with respect to the progression of atherosclerosis in coronary arteries subjected to percutaneous interventions.

Angioplasty, Balloon, Coronary↗
PubMed1997

Cardiac sympathetic activity in response to acute myocardial ischemia.

Although experimental evidence has demonstrated that brief periods of myocardial ischemia are not associated with norepinephrine overflow from the heart, cardiac sympathetic responses to myocardial ischemia in humans remain unclear. Eleven patients undergoing angioplasty of the left anterior descending coronary artery had cardiac norepinephrine spillover measured immediately before inflation, during the final minute of a 5-min balloon inflation, and 1 min after deflation. Angioplasty caused significant S-T segment elevation and a reduction in the transcardiac lactate extraction ratio. Cardiac norepinephrine spillover was reduced from a mean value of 58 +/- 14 pmol/min at control to 41 +/- 15 pmol/min during balloon inflation and 38 +/- 14 pmol/min after deflation (P < 0.05 vs. control for both inflation and deflation values). In contrast, during balloon inflation, there were significant increases in arterial norepinephrine and epinephrine concentrations. Therefore, a brief period of myocardial ischemia caused by angioplasty of the left anterior descending coronary artery does not result in cardiac sympathetic activation, despite evidence of generalized sympathoadrenal activation.

Angioplasty, Balloon↗
PubMed1995

Stenting for pulmonary artery stenosis following the Ross procedure.

A 34-year-old woman showed the development of significant main pulmonary artery obstruction along the supravalvar suture line 18 months following a Ross procedure. The patient underwent unsuccessful balloon angioplasty, followed by successful stent implantation. The angiographic narrowing disappeared postprocedure, and the excellent hemodynamic result maintained at 4 month follow-up.

Adult↗
PubMed1993

Contrast echocardiography during cardiac catheterization in patients with congenital heart diseases.

Contrast echocardiography performed during cardiac catheterization has mostly been limited to a few published case reports. We studied 37 patients with congenital heart disease to assess the capability of the method to diagnose cardiac shunts and valve regurgitation. Injections of 5% dextrose in water through an angiographic catheter were made to evaluate septal integrity and valve competence compared with conventional contrast angiography. An overall sensitivity of 93% and specificity of 78% were found. In four cases of atrial septal defect and seven of mitral regurgitation, the sensitivity was 100%. It was slightly lower for eleven cases of ventricular septal defect (91%) and four of patent ductus arteriosus (75%). When assessing aortic, tricuspid and pulmonary valve competence, the method proved to be more sensitive than conventional angiography to detect mild regurgitation. Contrast echocardiography is a sensitive and safe technique that may be used in association with conventional angiography reducing the need for radiographic contrast and ionizing radiation time.

Adolescent↗
PubMed1992

Absence of an aortic valve cusp, a cause of severe aortic regurgitation in infancy.

Congenital aortic regurgitation is an extremely rare cardiac lesion. This is a case report of an infant with a severe degree of valve regurgitation due to absence of the noncoronary aortic cusp. We show the echocardiographic, angiographic, and surgical aspects of the case, emphasizing the importance of a precise anatomical diagnosis and the problems of early valve replacement.

Angiocardiography↗
PubMed1992

Cardiopulmonary exercise testing early after catheter-balloon mitral valvuloplasty in patients with mitral stenosis.

Seven female patients (age 27 to 53 yr) with significant mitral stenosis performed continuous, incremental, maximal treadmill exercise tests the day before and within 3-5 days after catheter-balloon valvuloplasty. Mitral valve area determined by the echo-Doppler method increased from 0.9 +/- 0.3 cm2 to 1.9 +/- 0.7 cm2 (p < 0.02). Mean left atrial pressure was reduced from 24 +/- 8 to 13 +/- 7 mmHg (p < 0.01) and mean pulmonary artery pressure from 36 +/- 13 to 28 +/- 10 mmHg (p < 0.02) with a non-significant increase in cardiac output from 3.6 +/- 1.2 to 4.0 +/- 1.7 l/min. After catheter-balloon valvuloplasty all patients reached a higher maximal workload during exercise, and mean value of oxygen consumption and pulmonary ventilation were significantly lower in submaximal workloads. The calculated ventilatory equivalent for oxygen was significantly reduced in submaximal and in maximal workloads after catheter-balloon valvuloplasty. Peak oxygen consumption and the ventilatory anaerobic threshold were not changed after catheter-balloon valvuloplasty (pre 15.59 +/- 2.72 vs post 16.90 +/- 3.44 and pre 12.10 +/- 2.55 vs post 12.62 +/- 2.71 ml/kg/min, respectively). We concluded that after catheter-balloon valvuloplasty the cost of breathing was reduced and the oxygen consumed was more effectively utilized during exercise. Increases in peak oxygen consumption and in ventilatory anaerobic threshold would require circulatory and metabolic adaptations in response to increased physical activity and were not observed when cardiopulmonary tests were performed early after catheter-balloon valvuloplasty.

Adult↗
PubMed1991

Dipyridamole-thallium tests are predictive of severe cardiac arrhythmias in patients with left ventricular hypertrophy.

In a population of patients with chronic renal failure (CRF) and a high prevalence of left ventricular hypertrophy (LVH) undergoing chronic hemodialysis, we investigated the association between the results of dipyridamole-thallium tests (DTTs) and the occurrence of ventricular arrhythmias. We observed a positive significant association between positive DTTs and the occurrence of severe forms of ventricular arrhythmias. A significant association was also observed between the presence of severe LVH and the occurrence of severe ventricular arrhythmias. However, no association was found between the presence of LVH and the positivity of the DTT. As most of our patients with positive DTTs had unimpaired coronary circulations, we conclude that positive DTTs, although falsely indicative of impaired myocardial blood supply, does have an important clinical relevance, indicating increased risk of morbidity (and, possibly, mortality) due to ventricular arrhythmias in a population of CRF patients submitted to chronic renal function replacement program.

Adolescent↗