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Biomedical subjects

Osvaldo Pérez

Publications and source records attributed to Osvaldo Pérez.

9 recordsLinked to original sources
PubMed2006

[Usefulness of sublingual isosorbide to assess the reversibility of pulmonary hypertension in cardiac transplant candidates].

BACKGROUND: Continuous infusion of short life vasodilators are employed to test reversibility of pulmonary hypertension in cardiac transplant candidates. Sublingual isosorbide administration has not been described in the literature and it might be a simpler alternative. AIM: To evaluate sublingual isosorbide administration as a test of reversibility of pulmonary hypertension in heart failure. PATIENTS AND METHODS: Prospective evaluation of patients referred for cardiac transplant evaluation. Patients underwent right catheterization for hemodynamic measurements at baseline and after repeated doses of 5 mg sublingual isosorbide every 5 minutes until observing a decrease in pulmonary vascular resistance decrease or symptomatic hypotension. RESULTS: Twenty one patients, 18 men, age 49+/-15 years, were studied. Fourteen (66%) were transplanted. The mean sublingual isosorbide dose was 15+/-5 mg. After isosorbide administration, there was a significant decrease in mean arterial pressure (80+/-8.5 to 71+/-6.6 mmHg, p <0.0001), mean pulmonary artery pressure (38+/-11 to 26+/-7.8 mmHg, p <0.0001), systemic vascular resistance (1540+/-376 to 1277+/-332 dyn*s/cm5 p <0.001), pulmonary vascular resistance (3.5+/-2.2 to 2,5+/-1.6 Wood Units, p <0.05) and transpulmonary gradient (13+/-7 a 10+/-4 mmHg, p <0.004). The cardiac output increased from 3.96+/-0.7 to 4.38+/-0.9 L/min, p=0.05. The relation between pulmonary and systemic vascular resistance before and after isosorbide was 0.17 and 0.15, respectively (p=0.04). One transplanted patient with partial reversibility of pulmonary hypertension developed acute right heart failure. CONCLUSIONS: Sublingual isosorbide administration is useful and well tolerated to evaluate the reversibility of pulmonary hypertension prior cardiac transplant.

Administration, Sublingual↗
PubMed2005

Effects of carvedilol on oxidative stress and chronotropic response to exercise in patients with chronic heart failure.

BACKGROUND: Our previous studies suggest that the increase in heart rate from rest to peak exercise is reduced in patients with chronic heart failure (CHF) and this is associated with increased oxidative stress, as determined by malondialdehyde (MDA) plasma levels. AIM: To investigate the effects of carvedilol on the heart rate response to exercise and oxidative stress in patients with CHF. METHODS AND RESULTS: Thirty stable NYHA classes II-III CHF patients received carvedilol therapy for 6 months, at a mean maintenance dose of 25 mg (range 6.25-50 mg/day). After treatment, the patients showed a significant improvement in their functional NYHA class (p=0.013), increased left ventricular ejection fraction (LVEF) (24+/-1.4% to 31+/-2.3%, p=0.003) and 6-min walk distance (499+/-18 to 534+/-18 m, p=0.03), without changes in the peak VO2. At baseline, norepinephrine (NE) plasma levels increased with exercise (510+/-51 to 2513+/-230 pg/mL, p<0.001), and these levels were not affected by carvedilol. Chronotropic responsiveness index (increase in heart rate divided by the increase in NE from rest to peak exercise) was not changed by carvedilol (0.049+/-0.001 to 0.042+/-0.001, p=0.6). MDA levels of CHF patients decreased after treatment with carvedilol (2.4+/-0.2 to 1.1+/-0.2 microM, p<0.001), without changes in antioxidant enzyme activities. CONCLUSIONS: Carvedilol treatment in patients with CHF results in reduced oxidative stress without restoration of the chronotropic responsiveness index.

Adrenergic beta-Antagonists↗
PubMed2004

[Prognostic value of hyperuricemia in chronic heart failure].

BACKGROUND: Hyperuricemia has been proposed as a risk marker in chronic heart failure, but its value as an independent prognostic is not well established. AIM: To determine the prognostic value of hyperuricemia, in patients with chronic stable heart failure. PATIENTS AND METHODS: Forty six male patients with chronic heart failure, aged 62 +/- 13 years, were studied. Their election fraction was less than 40% and their serum creatinine was less than 2 mg/dl. Serum uric acid and catecholamines, maximal oxygen consumption (VO2 max) and left ventricular ejection fraction were measured. Mortality and the need for cardiac transplant were recorded as endpoints during a mean follow up of 39 +/- 18 months. The relationship between basal measures and the occurrence of events was analyzed using univariate and multivariate methods. RESULTS: Basal VO2 max and left ventricular ejection fraction were 16 +/- 4.6 ml/kg/min and 22 +/- 7% respectively. Eighteen patients died and three required transplantation during the follow up. Patients reaching these endpoints had a lower VO2 max and left ventricular ejection fraction and higher uric acid levels. Multivariate analysis accepted left ventricular ejection fraction (relative risk 0.89, 95% CI 0.82-0.97) and serum uric acid (relative risk 1.335 95% CI 1.02-1.74) as significant predictors of events. The relative risk for cardiac transplantation was 7.07 times higher among those with a serum uric acid over 7 mg/dl. CONCLUSIONS: A high serum uric acid is an independent predictor of bad prognosis in patients with stable chronic heart failure.

Analysis of Variance↗
PubMed2004

[Effects of carvedilol on functional capacity, left ventricular function, catecholamines and oxidative stress in patients with chronic heart failure].

INTRODUCTION AND OBJECTIVE: Carvedilol is an antioxidant and adrenergic antagonist with demonstrated benefits in terms of mortality from heart failure (HF). The aim of the present study was to evaluate clinical parameters, left ventricular function, oxidative stress levels and neurohumoral status at baseline and after 6 months of treatment with carvedilol in patients with chronic HF. PATIENTS AND METHOD: Thirty patients with chronic HF that was stable without beta blocker treatment were included. Functional class was II or III, and left ventricular ejection fraction (LVEF) was < 40%. Mahler score, distance walked in 6 min, peak oxygen consumption, LVEF, plasma catecholamine (norepinephrine) concentration and oxidative stress parameters were evaluated at baseline and after 6 months of treatment with carvedilol. RESULTS: Mean age was 59 (2) years, and 23 patients were men. After 6 months of treatment there were clinical improvements as measured by the Mahler score (from 6.8 to 11.0 points; P=.001) and the 6-min walk distance (from 499 [18] to 534 [17] m; P =.032), but no changes in peak oxygen consumption. The LVEF increased from 24 (1) to 31 (2)% (P=.003). In patients with chronic HF, plasma malondialdehyde concentration was significantly lower after 6 months (decrease from 2.4 [0.2] to 1.1 [0.2] micromol/l; P<.001). No significant changes were observed in plasma catecholamine levels or antioxidant enzyme activities. CONCLUSIONS: In patients with chronic HF, carvedilol treatment for 6 months was associated with clinical improvements, increased left ventricular function and decreased plasma concentrations of malondialdehyde, with no changes in plasma catecholamine levels.

Adrenergic beta-Antagonists↗
PubMed2003

Effects of glucose-insulin-potassium solution on myocardial salvage and left ventricular function after primary angioplasty.

OBJECTIVE: To evaluate the effects of glucose-insulin-potassium (GIK) therapy on infarct size and left ventricular function when used as an adjuvant therapy to primary angioplasty. DESIGN: Prospective, randomized, double-blind, placebo-controlled study. SETTING: Cardiac intensive care unit at a university hospital. PATIENTS: Thirty-seven patients with acute myocardial infarction for whom primary angioplasty was indicated. INTERVENTIONS: Eligible patients were randomized by a blinded pharmacist to GIK solution (30% glucose in water with insulin 50 U/L, and KCl 40 mM/L) vs. placebo at 1.5 mL/kg/hr for 24 hrs. MEASUREMENTS AND MAIN RESULTS: Tc 99m sestamibi myocardial scintigraphy was performed at admission and at 3 months. Primary end points were the changes in left ventricular ejection fraction (LVEF) and the size of salvaged myocardium. Baseline clinical characteristics were similar in both groups. At the 3-month follow-up, a significant overall decrease in infarct size (37 +/- 16% vs. 12 +/- 10%, p <.005) and an increase in LVEF (34 +/- 13% vs. 49 +/- 9%, p =.005) were observed. Patients randomized to GIK solution experienced a significant increase in their LVEF at 3 months (39 +/- 12 to 51 +/- 13, p =.002). Patients who received placebo had no significant differences between baseline and 3-month measurements (44 +/- 13 vs. 49 +/- 14, p = NS). There was a trend toward an increase in myocardial salvage in the GIK group, which did not reach statistical significance. When patients from both groups were compared directly, differences in LVEF improvement were no longer significant. CONCLUSIONS: GIK solution did not improve LVEF or decrease the infarct size among patients undergoing primary angioplasty.

Angioplasty, Balloon, Coronary↗
PubMed2003

[Catastrophic antiphospholipid syndrome and acute heart failure. Report of a case].

A 33 years old woman was admitted to the hospital after four days with cough, dyspnea, orthopnea and hemoptysis. Blood pressure was 170/90 mmHg, pulse was 112 and temperature was normal. She had cyanosis and a left ventricular gallop, without heart murmurs. A chest radiograph revealed pulmonary edema and echocardiogram showed a global left ventricular systolic disfunction. Oxygen and furosemide were started, but cardiopulmonary collapse ensued. The patient was supported with mechanical ventilation and treated with inotropic drugs. A right sided cardiac catheterization showed pulmonary wedge pressure of 18 mmHg and a cardiac index of 3 l/min/m2. The levels of creatinine and urea nitrogen were elevated and a urine protein was 97 mg/dl. Coagulation tests were normal except by a positive lupic anticoagulant. Markers of connective tissue diseases or vasculitis were negatives. The clinical evolution suggested that a catastrophic antiphospholipid syndrome was ongoing. Intravenous corticoids, gammaglobulin and cyclophosphamide were administered with transient improvement. On her fourth day of treatment, the patient presented sudden pulmonary bleeding and embolism. A plasmapheresis was performed with improvement of renal, cardiac and pulmonary function. After this episode, the patient has been treated with prednisone and oral anticoagulants treatment for the last two years, without further clinical events.

Acute Disease↗
PubMed2002

[Persistence of oxidative stress after heart transplantation: a comparative study of patients with heart transplant versus chronic stable heart failure].

INTRODUCTION AND OBJECTIVE: Chronic heart failure (CHF) is associated with oxidative stress. Heart transplantation, an important therapeutic alternative in these patients, could reduce oxidative stress by improving cardiac function. Our aim was to evaluate post-heart transplantation oxidative stress. PATIENTS AND METHOD: We studied three experimental groups: a) heart transplant recipients without evidence of rejection (n = 11); b) NYHA class III CHF patients (n = 19), and c) healthy control subjects (n = 14). Oxidative stress was assessed by measuring plasma malondialdehyde levels (MDA), and determining the enzymatic activities of glutathione peroxidase (GSH-Px), catalase (CAT), and superoxide dismutase (SOD). RESULTS: The demographic characteristics of the three groups were similar. Mean time from transplantation was 20.0 4.8 months. Mean MDA plasma levels in heart transplantation and CHF patients were significantly higher than in normal subjects (3.35 0.8; 3.27 1.7 y 0.9 0.3 microM, respectively). GSH-Px activity increased after transplantation compared to control subjects (0.40 0.06 and 0.33 0.05 U/g Hb, respectively), but not the CHF group. A significant decrease in SOD activity was found in the heart transplant vs. CHF group (0.44 0.1 vs. 0.87 0.6 U/mg Hb). There were no differences in CAT values between heart transplant and CHF patients. CONCLUSION: These findings demonstrated the presence of permanent oxidative stress in patients who have undergone heart transplantation, characterized by an increase in MDA and a decrease in SOD activity, despite an increase in GSH-Px activity.

Adult↗