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Biomedical subjects

P L Da Luz

Publications and source records attributed to P L Da Luz.

10 recordsLinked to original sources

Antagonism of the acute hemodynamic effects of captopril in decompensated congestive heart failure by aspirin administration.

The concomitant use of angiotensin-converting enzyme inhibitors and aspirin may cause pharmacological antagonism. Hence we examined the effect of aspirin on the neurohormonal function and hemodynamic response to captopril in heart failure patients. Between April 1999 and August 2000, 40 patients were randomized into four equal groups: 1) captopril, 2) aspirin, 3) captopril-aspirin: captopril was given alone on the first day, followed by aspirin on the remaining days, and 4) aspirin-captopril: aspirin was given alone on the first day, followed by captopril on the remaining days. Hemodynamic, norepinephrine and prostaglandin measurements were performed pre- and post-medication for 4 days. Captopril (50 mg) was given orally every 8 h and 300 mg aspirin was given on the first day, and 100 mg/day thereafter. In the captopril group and only on the first day of captopril-aspirin, captopril produced increases in cardiac index (2.1 +/- 0.6 to 2.5 +/- 0.5 l min-1 m-2, P<0.0001), and reduced peripheral vascular resistance (1980 +/- 580 to 1545 +/- 506 dyn s-1 cm-5/m , P<0.0001) and pulmonary wedge pressure (20 +/- 4 to 15 +/- 4 mmHg, P<0.0001). In contrast, aspirin alone or associated with captopril showed no significant hemodynamic changes. Norepinephrine decreased (P<0.02) only in the captopril group. Prostaglandin levels did not differ significantly among groups. Thus, aspirin compromises the short-term hemodynamic and neurohormonal effects of captopril in patients with acute decompensated heart failure.

Aged↗

Maternal and fetal outcome in pregnant women with Eisenmenger's syndrome.

Interruption of pregnancy is usually recommended for pregnant women with Eisenmenger's syndrome. We studied 13 pregnancies in 12 women with this syndrome, who decided to carry on with their pregnancy despite recommendation for therapeutic abortion. The mean age was 27 years. Five patients had ventricular septal defect; two, persistent ductus arteriosus; one, a combination of both; two, atrial septal defect; one, atrioventricular septal defect and one patient a combination of ventricular and atrial septal defects. Mean systolic and diastolic arterial pulmonary pressures were 112.7 and 61.7, mmHg, respectively. There were three spontaneous abortions, one premature labour at 23 weeks of gestation and two maternal deaths during the 23 and 27 weeks of gestation. Seven patients who reached the end of the second trimester were hospitalized until delivery and received heparin (20,000 to 40,000 units per day) and oxygen therapy. Caesarean section was performed in all patients as a result of worsening maternal or fetal clinical condition during the third trimester of gestation. all the mothers were discharged from hospital but one of them died on the 30th day post-partum. Five of the eight infants were premature, three were small babies for gestational age and all were discharged from hospital with the exception of one who died 48 h after birth. In conclusion, although pregnancy should be discouraged in women with Eisenmenger's syndrome, it can be successful. In this study, prolonged bed rest, the use of heparin and oxygen therapy presumably positively influenced maternal and infant outcomes.

Adolescent↗

Prognostic significance of silent myocardial ischemia after a first uncomplicated myocardial infarction.

Forty asymptomatic patients were studied after a first uncomplicated myocardial infarction. They were 36 men and 4 women, with a mean age of 52.6 yr; the location of myocardial infarction was in the anterior wall in 18 (45%) patients and in the inferior wall in 22 (55%). The patients were submitted to: (1) 48-h Holter monitoring, during the 2nd and 8th weeks after the acute event; (2) exercise testing during the same periods; (3) cardiac catheterization and coronary arteriography. Patients with clinical conditions associated with cardiac rhythm disturbances or repolarization abnormalities were excluded. The electrocardiographic methods identified 11 (27.5%) patients with silent myocardial ischemia. Patients with and without silent ischemia were similar in relation to sex, age, coronary risk factors, arrhythmias, left ventricular function and follow-up. Patients with silent ischemia had more inferior wall myocardial infarctions, but the difference was not statistically significant. Patients with silent ischemia had significantly more extensive coronary artery disease (45.5% multivessel disease) when compared to those without ischemia (14.8% multivessel disease) (p < 0.05). After a 2-yr follow-up, 4 (36.4%) patients with and 1 (3.4%) without silent ischemia had a coronary event (p < 0.05). Kaplan-Meier analysis demonstrated a significantly higher cumulative probability of not experiencing a new coronary event for the patients without silent ischemia (96.5%) as compared to those with silent ischemia (62.3%) (p < 0.01). Our results suggest that silent myocardial ischemia after a first uncomplicated myocardial infarction carries an adverse prognosis and should be routinely investigated.

Adult↗

Frequency and significance of cardiac rhythm disturbances in healthy elderly individuals.

The authors examined the prevalence and significance of cardiac rhythm disturbances in healthy elderly individuals. They selected 26 men with active lifestyles, aged 70-81 years, after clinical, routine blood tests, chest radiographs, echocardiography, resting and exercise electrocardiography, and Gated cardiac blood imaging evaluations. The men were submitted to continuous electrocardiographic monitoring during their daily routine. The recording time ranged from 838 to 1,432 min (average = 1,307 +/- 153 min). Clinical follow-up was done every six months. Sinus rhythm predominated in all subjects. The maximal, minimal, and average heart rate ranges (beats/min) were, respectively: during sleeping periods, 60-115 (85.8 +/- 13.2), 42-80 (56.6 +/- 8.7), 51-85 (64.0 +/- 8.8); and during awake periods, 85-150 (118.4 +/- 16.4), 50-85 (64.1 +/- 9.1), 61-90 (75.3 +/- 8.3). The longest sinus pauses were observed during sleep and ranged from 0.8 to 2.5 sec (1.25 +/- 0.34 sec). Atrial ectopic beats were observed in 20 individuals (76.9%). They were frequent in four (15.4%) and repetitive in nine (34.6%) of them. Short-lasting episodes of paroxysmal atrial tachycardia and paroxysmal atrial flutter were observed in one case each. Ventricular ectopic beats were recorded in 20 individuals (76.9%). They were frequent in 6 (23%) and multiform in 13 (50%) of them. Couplets were observed in 5 cases (19.2%) and episodes of nonsustained ventricular tachycardia were present in 3 individuals (11.5%). No symptoms were referred by any individual during recording. No clinical signs of heart disease or symptoms were noticed during the average 40 +/- 7.2 months of follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

Contrasting influences of alterations in ventricular preload and afterload upon systemic hemodynamics, function, and metabolism of ischemic myocardium.

This study of anesthetized, open-chest dogs compares the effects of primary increases in left ventricular preload and afterload upon global and regional myocardial function and metabolism in the presence of a left anterior descending coronary artery stenosis (LAD). When LAD flow was reduced to 40-50% of control, regional systolic shortening declined by 20 to 25% and regional lactate extraction changed to production. In seven control dogs the mechanical abnormalities persisted during the 30 min of observation, but lactate production was reduced spontaneously. In ten dogs, increases in left ventricular end-diastolic pressure (LVEDP) during dextran infusion were associated with increases in cardiac output and regional systolic shortening; however, regional lactate production also increased (P less than 0.05) despite an augmentation in LAD flow. In seven dogs mean arterial pressure increased by an average of 32 mm Hg during angiotensin infusion (0.2 to 0.4 mug/kg/min); LVEDP did not change but cardiac output decreased significantly. LAD artery flow improved markedly and lactate production shifted to extraction (P less than 0.05) while systolic shortening remained unchanged. When angiotensin was discontinued, lactate extraction worsened again. Thus, in the presence of a severe coronary stenosis, a primary increase in preload improves cardiac output but at the expense of aggravated ischemia. In contrast, a primary increase in afterload reduces cardiac output but may improve perfusion and lactate uptake of the ischemic myocardium.

Angiotensin II↗

Functional significance of regional ischemic contraction abnormalities.

To evaluate the progression of segment function following induction of ischemia, the left anterior descending coronary artery was ligated (eight dogs) or cannulated and perfused at various pressures via a bypass-oxygenator (six dogs). Mercury-in-silastic length gauges were sutured to the anterior left ventricle, and pressure was recorded by a catheter-tipped transducer. Segment function was determined from the area of the pressure-length loop by plotting instantaneous left ventricular pressure against segment length and by evaluation of the degree of systolic shortening. Segment function decreased linearly as flow in the left anterior descending artery was decreased in a stepwise fashion by reduction in perfusion pressures from 100 to 20 mm Hg. With both left anterior descending coronary artery ligation and stepwise flow reduction, the pressure-length loop invariably showed four clearly identifiable morphologic patterns which relate conceptually to the specific left ventricular contraction patterns: dyssynchrony, hypokinesis, akinesis, and paradoxic systolic expansion. Re-oxygenation following occlusion invariably revealed return to a normal pattern in reverse order. This study demonstrates that a consistent and predictable progression of segmental contraction abnormalities occurs with ischemia.

Animals↗