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Biomedical subjects

A C Barretto

Publications and source records attributed to A C Barretto.

At least 19 recordsLinked to original sources
PubMed2001

Acute precipitants of congestive heart failure exacerbations.

BACKGROUND: Few studies have prospectively and systematically explored the factors that acutely precipitate exacerbation of congestive heart failure (CHF) in patients with left ventricular dysfunction. Knowledge of such factors is important in designing measures to prevent deterioration of clinical status. The objective of this study was to prospectively describe the precipitants associated with exacerbation of CHF status in patients enrolled in the Randomized Evaluation of Strategies for Left Ventricular Dysfunction Pilot Study. METHODS: We conducted a 2-stage, multicenter, randomized trial in 768 patients with CHF who had an ejection fraction of less than 40%. Patients were randomly assigned to receive enalapril maleate, candesartan cilexetil, or both for 17 weeks, followed by randomization to receive metoprolol succinate or placebo for 26 weeks. Investigators systematically documented information on clinical presentation, management, and factors associated with the exacerbation for any episode of acute CHF during follow-up. RESULTS: A total of 323 episodes of worsening of CHF occurred in 180 patients during 43 weeks of follow-up; 143 patients required hospitalization, and 5 died. Factors implicated in worsening of CHF status included noncompliance with salt restriction (22%); other noncardiac causes (20%), notably pulmonary infectious processes; study medications (15%); use of antiarrhythmic agents in the past 48 hours (15%); arrhythmias (13%); calcium channel blockers (13%); and inappropriate reductions in CHF therapy (10%). CONCLUSIONS: A variety of factors, many of which are avoidable, are associated with exacerbation of CHF. Attention to these factors and patient education are important in the prevention of CHF deterioration.

Adrenergic beta-Antagonists↗
PubMed2001

Abnormal neurovascular control during exercise is linked to heart failure severity.

The purpose of this study was to determine if abnormalities of sympathetic neural and vascular control are present in mild and/or severe heart failure (HF) and to determine the underlying afferent mechanisms. Patients with severe HF, mild HF, and age-matched controls were studied. Muscle sympathetic nerve activity (MSNA) and forearm vascular resistance (FVR) in the nonexercising arm were measured during mild and moderate static handgrip. MSNA during moderate handgrip was higher at baseline and throughout exercise in severe HF vs. mild HF (peak MSNA 67 +/- 3 vs. 54 +/- 3 bursts/min, P < 0.0001) and higher in mild HF vs. controls (33 +/- 3 bursts/min, P < 0.0001), but the change in MSNA was not different between the groups. The change in FVR was not significantly different between the three groups during static exercise. During isolation of muscle metaboreceptors, MSNA and blood pressure remained elevated in normal controls and mild HF but not in severe HF. During mild handgrip, the increase in MSNA was exaggerated in severe HF vs. controls and mild HF, in whom MSNA did not increase. In summary, the increase in MSNA during static exercise in severe HF appears to be attributable to exaggerated central command or muscle mechanoreceptor control, not muscle metaboreceptor control.

Adult↗
PubMed2001

Muscle metaboreflex control is diminished in normotensive obese women.

There is no information about the muscle metaboreflex control in obese individuals. In 40 normotensive obese women (OW; body mass index 33.5 +/- 0.4 kg/m2, age 32.4 +/- 1.1 yr) and 15 age-matched, normotensive lean women (LW; body mass index 22.7 +/- 0.8 kg/m2, age 34.4 +/- 1.4 yr), we measured muscle sympathetic nerve activity (MSNA) and forearm blood flow (FBF) in the nonexercising forearm during static exercise at 10 and 30% of maximal voluntary contraction (MVC). Baseline MSNA (38 +/- 2 vs. 31 +/- 1 bursts/min, P = 0.001) and mean blood pressure were significantly higher in OW compared with LW. FBF was significantly lower, whereas forearm vascular resistance was significantly higher in OW. During 10% MVC, MSNA increased similarly in both groups, but during 30% MVC, MSNA was higher in LW. FBF and forearm vascular resistance responses during both 10 and 30% MVC were similar between groups. During posthandgrip circulatory arrest, MSNA remained significantly elevated compared with baseline in both groups, but this increase was significantly lower in OW (3.8 +/- 0.82 vs. 9.4 +/- 1.03 bursts/min, P = 0.002). In conclusion, muscle metaboreflex control of MSNA is blunted in OW. MSNA responses are not augmented during selective activation of central command/mechanoreceptors and metaboreceptors, despite increased MSNA levels in OW. Muscle vasodilatory response during graded handgrip isometric exercise is preserved in OW.

Adult↗
PubMed2001

Reversibility of ventricular dysfunction. Clinical experience in a medical office.

OBJECTIVE - To describe clinical observations of marked improvement in ventricular dysfunction in a medical office environment under circumstances differing from those in study protocols and multicenter studies performed in hospital or with outpatient cohorts. METHODS - Eleven cardiac failure patients with marked ventricular dysfunction receiving treatment at a doctors office between 1994 and 1999 were studied. Their ages ranged from 20 and 66 years (mean 39.42+/-14.05 years); 7 patients were men, 4 were women. Cardiopathic etiologies were arterial hypertension in 5 patients, peripartum cardiomyopathy in 2, nondefined myocarditis in 2, and alcoholic cardiomyopathy in 4. Initial echocardiograms revealed left ventricular dilatation (average diastolic diameter, 69.45+/-8.15mm), reduced left ventricular ejection fraction (0.38+/-0.08) and left atrial dilatation (43.36+/-5.16mm). The therapeutic approach followed consisted of patient orientation, elimination of etiological or causal factors of cardiac failure, and prescription of digitalis, diuretics, and angiotensinconverting enzyme inhibitors. RESULTS - Following treatment, left ventricular ejection fraction changed to 0.63+/-0.09; left ventricular diameters changed to 57.18+/-8.13mm, and left atrium diameters changed to 37.27+/-8.05mm. Maximum improvement was noted after 16.9+/-8.63 (6 to 36) months. CONCLUSION - Patients with serious cardiac failure and ventricular dysfunction caused by hypertension, alcoholism, or myocarditis can experience marked improvement in ventricular dysfunction after undergoing appropriate therapy within the venue of the doctor's office.

Adult↗
PubMed2001

Muscle sympathetic nerve activity and hemodynamic alterations in middle-aged obese women.

To study the relationship between the sympathetic nerve activity and hemodynamic alterations in obesity, we simultaneously measured muscle sympathetic nerve activity (MSNA), blood pressure, and forearm blood flow (FBF) in obese and lean individuals. Fifteen normotensive obese women (BMI = 32.5 +/- 0.5 kg/m2) and 11 age-matched normotensive lean women (BMI = 22.7 +/- 1.0 kg/m2) were studied. MSNA was evaluated directly from the peroneal nerve by microneurography, FBF was measured by venous occlusion plethysmography, and blood pressure was measured noninvasively by an autonomic blood pressure cuff. MSNA was significantly increased in obese women when compared with lean control women. Forearm vascular resistance and blood pressure were significantly higher in obese women than in lean women. FBF was significantly lower in obese women. BMI was directly and significantly correlated with MSNA, blood pressure, and forearm vascular resistance levels, but inversely and significantly correlated with FBF levels. Obesity increases sympathetic nerve activity and muscle vascular resistance, and reduces muscle blood flow. These alterations, taken together, may explain the higher blood pressure levels in obese women when compared with lean age-matched women.

Adult↗
PubMed1999

Endomyocardial fibrosis associated with massive calcification of the left ventricle.

This is the report of a rare case of endomyocardial fibrosis associated with massive calcification of the left ventricle in a male patient with dyspnea on great exertion, which began 5 years earlier and rapidly evolved. Due to lack of information and the absence of clinical signs that could characterize impairment of other organs, the case was initially managed as a disease with a pulmonary origin. With the evolution of the disease and in the presence of radiological images of heterogeneous opacification in the projection of the left ventricle, the diagnostic hypothesis of endomyocardial disease was established. This hypothesis was later confirmed on chest computed tomography. The patient died on the 16th day of the hospital stay, probably because of lack of myocardial reserve, with clinical findings of refractory heart failure, possibly aggravated by pulmonary infection. This shows that a rare disease such as endomyocardial fibrosis associated with massive calcification of the left ventricle may be suspected on a simple chest X-ray and confirmed by computed tomography.

Adult↗
PubMed1998

Atrial fibrillation in endomyocardial fibrosis is a marker of worse prognosis.

We studied the incidence of AF in patients with endomyocardial fibrosis (EMF) and its influence on prognosis and associated clinical events. One hundred and sixty consecutive patients with EMF were followed for a mean period of 4 years. Their mean age was 39.7 years. There were 114 women. During follow-up there were 56 deaths. Eighty-eight patients (55%) were submitted to surgical intervention. AF was observed in 58 cases (36.2%). The presence of AF was associated with a greater prevalence of dyspnea, peripheral edema, hepatomegaly, lower left ventricular ejection fraction, lower right ventricular systolic pressure (37.8 vs 45.6 mmHg, P=0.0392), and greater incidence of tricuspid regurgitation (86.0 vs 63.2%, P=0.004). AF was more frequent among patients in whom the disease involved the right ventricle, particularly those with intense fibrosis. Overall, patients with AF had a higher mortality rate than those who did not have AF (43.1 vs 30.3%, P=0.0195), but among those submitted to surgery, AF did not have an impact on survival. In conclusion, AF is frequent among patients with EMF. It is more prevalent among patients with right ventricular involvement and its presence is associated with a greater incidence of heart failure. AF is associated with worse prognosis, but surgery potentially reverses this bad evolution.

Adult↗
PubMed1998

[Effect of exercise duration on the magnitude and duration of post-exercise hypotension].

PURPOSE: Considering that exercise duration may play a role in post-exercise hypotension, we tested the hypothesis that a prolonged submaximal exercise would lead to a greater and longer blood pressure fall after exercise than a shorter exercise bout. METHODS: Experimental protocol-10 subjects were submitted to two cycle ergometer exercise trials (25 and 45 min) at 50% of VO2 peak. Control protocol-12 subjects rested in the sitting position for 45 min. Blood pressure (BP) was measured before (20 min) and after (90 min) rest or exercise bouts. RESULTS: Systolic BP decreased significantly after exercise and this reduction was greater and lasted longer after 45 min of exercise. Mean and diastolic BP decreased after exercise and they were significantly lower during the 45 min session. Control protocol--no change in BP was observed after resting condition. CONCLUSION: A longer exercise bout leads to a greater and longer post-exercise hypotension.

Adult↗
PubMed1998

[Comparison between the prescription of physical training intensity based on the standard ergometric test and on the ergospirometric test].

PURPOSE: To compare the lower (LL) and upper limits (UL) of exercise intensity prescription based on standard exercise test (60-70% of estimated VO2max or 70-85% of HRmax measured) with exercise intensity prescription based on cardiopulmonary exercise test [anaerobic threshold (AT) and respiratory compensation point (RCP)]. METHODS: Fourty seven men (30 +/- 5 years) who were submitted to a progressive cardiopulmonary exercise test until exhaustion were divided in subgroups according to treadmill speed during exercise test (4 or 5 mph) and the physical capacity [lower (LPC) and moderate physical capacity (MPC)]. RESULTS: The LL of the indirect exercise intensity prescription showed VO2 and HR values significantly higher than VO2 and HR values measured at AT (4 mph = 34.4 +/- 4.5 vs 19.6 +/- 4.6 and 5 mph = 28.9 +/- 2 vs 18.9 +/- 5.4, and LPC = 32.0 +/- 4.1 vs 17.2 +/- 2.8 and MPC = 31.6 +/- 4.9 vs 21.1 +/- 5.7 mlO2.kg-1.min-1) and (4 mph = 128.9 +/- 7.8 vs 113.1 +/- 15.6 and 5 mph = 130.3 +/- 5.2 vs 114.1 +/- 18.9, and LPC = 127.6 +/- 7.2 vs 109.3 +/- 13.2 and MPC = 131.2 +/- 5.7 vs 117.4 +/- 19.2 bpm) The UL of the indirect exercise intensity prescription in 4 mph and LPC group showed VO2 values significantly higher than those measured at RCP (40.1 +/- 5.3 vs 32.2 +/- 4.3 and 37.4 +/- 4.8 vs 30.6 +/- 2.5 mlO2.kg-1.min-1, respectively), but similar HR values to those obtained at RCP. CONCLUSION: The LL of prescription based on standard exercise test overestimate the AT, whereas the UL seem adequate only for subjects with moderate physical capacity.

Adult↗
PubMed1998

[Effect of myocardial revascularization on asymptomatic ischemic episodes].

PURPOSE: To evaluate the effect of coronary artery bypass graft surgery (CABG) on ischemic asymptomatic episodes (IAE). METHODS: Twenty eight males (means age 57.3 +/- 9.6 years) with stable angina and no microcirculation abnormalities, who presented with IAE after medication withdrawal, were studied using ambulatory electrocardiography monitoring. Presence of IEA was analyzed before and 4 months after CABG according to its frequency and heart rate (HR) response. CAGB was considered complete in 75% of the cases. RESULTS: The number or IAE was reduced from 162 (9 symptomatic) in the preoperative period to 4 after surgery (p < 0.05). In two patients with IAE in the postoperative period, coronariography confirmed obstruction of aortocoronary grafts. Analysis of HR at the beginning and peak of IAE suggested as mechanisms both reduced blood flow and increased oxygen consumption by the myocardium. CONCLUSION: CABC eliminated IAE regardless of HR. When IAE is present after surgery, graft occlusion should be suspected.

Adult↗
PubMed1998

[Diuretics improve functional capacity in patients with congestive heart failure].

PURPOSE: The 6-9 minute walking test was used in this study to evaluate the impact of these drugs on functional capacity of patients admitted to the Hospital because of Heart Failure (CHF). METHODS: Ten patients (5 males and 5 females) with mean age of 47 years and NYHACHF functional class III or IV underwent a 6-9 minute walking test at admission and on the day of discharge from the Hospital. The following parameters were evaluated both at admission and discharge: body weight, echocardiography-derived LV dimensions and function, plasmatic levels of sodium, potassium, Bun, creatinine, hemoglobin and hematocrit. Treatment consisted of increasing outpatient dose of furosemide (IV and/or PO) plus the association of thiazide if necessary. The previous dose regimen of digitalis, ACE inhibitors or the association nitrate and hydralazine was kept unchanged. RESULTS: Time to compensation of CHF varied from 4 to 30 days (mean 8.7 +/- 7.8 days). LV end diastolic dimension varied from 47 to 81mm. LV EF spanned from 0.26 to 0.74. The 6min walking distance improved from 193.4 +/- 71.5m to 341.8 +/- 67.7m (p < 0.00002) and the 9min walking distance from 268.1 +/- 119.6m to 518.0 +/- 114.8m (p < 0.00005). Hemoglobin, hematocrit, BUN, creatinine and sodium levels were unchanged from admission to discharge, whereas plasma potassium level increased from 4.0 +/- 0.9mEq/l to 4.69 +/- 1.00mEq/l (p = 0.01), and body weight was reduced from 58.9 +/- 6.42kg to 52.9 +/- 5.3lkg (p < 0.0006). CONCLUSION: Compensating CHF with diuretics leads to a significant improvement in physical capacity. This benefit already evident in the in-hospital phase.

Adult↗
PubMed1998

[Heart failure at a large tertiary hospital of São Paulo].

PURPOSE: To study the incidence, main causes, aggravating factors and secondary diagnoses of heart failure (HF) during 1995 at the Instituto do Coração of São Paulo. METHODS: Data from hospitalized patients according to the PRODESP data base were analyzed. The following data were studied; age, sex, principal and secondary diagnoses, surgical procedures and mortality. To analyze the data, tables according to sex, age and main cause were built. Analysis of variance and t test were employed to verify differences between groups. RESULTS: In 1995, 903 out of 9620 patients were hospitalized due to HF. The majority were male (60.4%) and the patients' age was between two days and 98 years old (mean 52.6). Ischemic (32.6), dilated (25.8%) and valvar heart disease (22%) were the main causes of HF. 32.1% were submitted to correction of the HF main cause, specially those with valvar heart disease (62.3%). There was greater incidence of multiple diagnoses in aged patients. The mortality was greater in patients younger than 20 and in those older than 80 years old. CONCLUSION: The incidence of HF at INCOR during 1995 was 9.38%. Ischemic myocardiopathy was the most frequent HF cause. The mortality was greater among children, probably because of heart disease complexity and, in the above-80 group due to the greater comorbidity.

Adolescent↗
PubMed1998

[Heart failure].

Explore the source record for details and available documents.

Heart Failure↗
PubMed1998

[Heart rate response and its variability during different phases of maximal graded exercise].

PURPOSE: Heart rate variability (HRV) has been studied at rest as a non-invasive tool for the assessment of cardiac autonomic control and, its attenuation is related to cardiovascular risk. However, during exercise, when important neural changes take place, HRV behaviour is not well established. The aim of this investigation was to study the heart rate (HR) and HRV responses during the different metabolic phases of maximal graded exercise in young men. METHODS: Seventeen men (age 28 +/- 6 years) were submitted to a graded cardiopulmonary exercise test in a cycloergometer (30W/3 min). To study HR and HRV (standard-deviation), the electrocardiographic signal was amplified and acquired beat-to-beat in a computer at a frequency of 125 Hz (AT/Codas). RESULTS: The HR increases concomitantly to the increase in exercise intensity. The HRV was significantly lower than rest values after exercise intensities of 60% of peak exercise oxygen uptake, 45-60% of maximal power and, after anaerobic threshold intensity. CONCLUSION: This results suggest that HRV measured by standard deviation of HR decreases during exercise phases when HR increment is determined mainly due to vagal withdrawal.

Adult↗
PubMed1998

First-degree kinship with young coronary artery disease patients markedly increases lipid-level disorders in asymptomatic hypertensives.

BACKGROUND: Association of hypertension and serum lipid disorders has been demonstrated in previous studies. However, there are no investigations about the behaviour of serum lipids in asymptomatic hypertensive individuals who are first degree relatives of young coronary patients. OBJECTIVE: To determine the degree of lipid disorders in Brazilian hypertensive individuals who are first degree relatives of young coronary patients. METHODS: There were four study groups, 2 in each arm of the study: a) 846 subjects without any evidence of heart disease or diabetes who were first degree relatives of patients who underwent coronary artery bypass grafting (CABG) surgery before 55 years-of-age. Of these subjects, 226 individuals were hypertensive (group Hyp F), and 620 were normotensive (group Normo F): b) 910 hospital employees without evidence of cardiovascular disease and family history of coronary artery disease of whom 152 were hypertensive (group Hyp NF), and 758 were normotensive (group Normo NF). Hypertension was defined as blood pressure greater than 140/90 mmHg. The following serum lipid measurements were performed: total cholesterol, high-density lipoprotein cholesterol (HDLC), low-density lipoprtein cholesterol (LDLC), and triglycerides. Lipid disorders were defined according to the 2nd Report of the National Cholesterol Education Program (NCEP) (total cholesterol>240 mg/dl; LDLC>160 mg/dl; triglycerides>200 mg/dl). The frequency of lipid disorders in each group was calculated. Subjects were classified according to their body mass index (BMI) as normal, overweight, or obese. The following statistical analyses were performed as indicated: ANOVA (with Tukey's corrections for multiple comparisons), chi-square (x2), and odds ratio (OR). RESULTS: Hyp F subjects had significantly higher total cholesterol, LDLC and triglyceride levels, and significantly lower levels of HDLC than all other groups. There was a higher frequency of lipid disorders in Hyp F subjects than in Hyp NF individuals, with a significant OR of 1.71 (CI 1.26-2.32) and 2.09 (CI 1.48-2.72) for total cholesterol and LDLC respectively. When compared to Normo F subjects, Hyp F individuals had significantly higher risk of having lipid disorders: total cholesterol (OR=8), LDLC (OR=6), and triglycerides (OR=5). There was a higher frequency of obesity among Hyp F patients than in all other groups. The frequency of subjects who were overweight or obese was higher in Hyp F than in Hyp NF subjects. CONCLUSION: Hypertensive patients who were first degree relatives of patients revascularized at a young age had a higher prevalence of lipid disorders, particularly higher total cholesterol and LDLC, than hypertensive individuals without this family history. These individuals may have a greater genetic propensity to develop lipid disorders.

Adult↗
PubMed1997

[Cardiac amyloidosis. A disease with many faces and different prognosis].

PURPOSE: To identify the principal forms of cardiac amiloydosis presentation in a terciary hospital. METHODS: Eight cases with cardiac amyloidosis were identified. Five were women, their ages ranged from 23 to 83 years (mean 62). After a medical history and clinical examination the patients were submitted to complementary tests: electrocardiogram (EKG), echocardiogram (ECHO), scintigraphy with technecium pirophosphate and cardiac biopsy these results allowed the identification of their clinical situation. RESULTS: Seven patients referred dyspnea, 6 were in heart failure, 1 patient had syncope. The EKG identified complete atrioventricular (AV) block in 4 patients, and antero septal inactive area in the other 4. The ECHO showed normal cardiac diameter in all (mean left ventricular diastolic diameter of 46.8) and slight reduction of left ventricular ejection fraction; hypertrophy of the left ventricular septal and posterior walls in all cases, in 7 cases there was a hyper refractile granular sparkling ECHO. Two different groups were identified: one with complete AV block and the second with restrictive cardiomyopathy. The prognosis was different in these two groups. Those with complete AV block evolved better after pacemaker implantation and those with restrictive cardiomyopathy had refractory heart failure and 3 of them died. CONCLUSION: The increased free wall and septal thickness, the slight systolic dysfunction and the infiltration aspect at ECHO allow us to identify the great majority of the cases. Those patients with restrictive cardiomyopathy evolve with refractory heart failure and most of them die in a few months.

Adult↗
PubMed1997

[Medical treatment of heart failure at a tertiary hospital of São Paulo].

PURPOSE: To study how patients with heart failure (HF) are treated in a tertiary hospital in São Paulo. METHODS: One hundred patients with HF during ambulatory care were analyzed. Seventy-six were men, and the average population age was 56.8 years old. All patients were submitted to echocardiogram, which identified ventricular diameters ranging between 48 and 89 mm (average 65.9) and ejection fraction (EF) between 0.22 and 0.59 (average 0.43). The cause of HF was ischemic in 42 cases, dilated cardiomyopathy in 28, valvular heart disease in 12, Chagas' disease in 10 and systemic hypertension in 8 patients. The prescribed treatment was analyzed, with attention to the prescription and dosage of angiotensin converting enzyme (ACE) inhibitors. We also analyzed whether the cause and/or the degree of HF influenced the treatment chosen. RESULTS: Eighty-seven patients received ACE inhibitors, 31 received doses below those recommended in the large trials. Digoxin was prescribed in 69 cases, diuretics in 85, and aspirin in 33. When dividing the patients according to EF, the group with EF below 0.45 was prescribed more often ACE inhibitors (91.5% vs 80.4%) and had more often usage of adequate doses (61% vs 48.7%). CONCLUSION: In this sample the majority of the patients were treated according to modern recommendations and tolerated well ACE inhibitors, however 1/3 did not receive ACE inhibitors in the recommended doses. Treatment based on betablockers or angiotensin II inhibitors were not routinely employed.

Aged↗