Biomedical subjects

J Neves

Publications and source records attributed to J Neves.

At least 19 recordsLinked to original sources

PubMed1999

Surgery for atrial fibrillation using radiofrequency catheter ablation: assessment of results at one year.

OBJECTIVE: The results obtained in 43 patients using direct intraoperative radiofrequency catheter ablation, as an alternative to surgical incisions, to perform atrial fibrillation surgery, are presented. METHODS: Forty-three patients with ages ranging from 43 to 74 years (x = 59), with chronic atrial fibrillation with an average duration 6+/-5 years were operated. Eleven patients suffered from clinically relevant tachyarrythmia and eight had previous thromboembolic events. All but one patient had concomitant mitral valve surgery. Direct intraoperative radiofrequency catheter ablation was used to perform endocardial bilateral isolation of the pulmonary veins from the left atrium. RESULTS: There were no local or general complications, namely bleeding or thromboembolic events. Of the 33 patients with more than 3 months of follow-up, 36% remained in atrial fibrillation (Santa Cruz score 0); 30% had Score 4; 18% had Score 3; 6% had Score 2; 9% had Score 1. CONCLUSIONS: We conclude that the use of intraoperative radiofrequency catheter ablation is fast and safe. Presently, this is our method of choice for surgical treatment of atrial fibrillation in mitral patients.

Adult↗

PubMed1999

Electrosurgical treatment of atrial fibrillation with a new intraoperative radiofrequency ablation catheter.

BACKGROUND: To assess the efficacy of a new catheter for intraoperative radiofrequency ablation. METHODS: We operated 35 mitral patients with atrial fibrillation of which 27 had chronic atrial fibrillation with a mean duration of 8 +/- 6 years. Most patients were in functional class III or IV. All patients were operated under cardiopulmonary bypass using sternotomy in 29 patients, right thoracotomy in 5 and left thoracotomy in 1. RESULTS: Bilateral pulmonary vein isolation with radiofrequency catheter ablation was achieved in 7 +/- 4 minutes. There was no mortality or morbidity. Out of the 27 patients with one to three months follow-up 60% were out of atrial fibrillation and 48% had both atria contracting (scores 3 and 4). A longer time is required to assess the end result of these techniques, because the complete healing of the ablation lesions takes 3 to 6 months. CONCLUSIONS: We conclude that with appropriate tools and settings the use of intraoperative radiofrequency catheter ablation is fast, safe and effective. Its indications can be extended to other types of atrial fibrillation patients.

Aged↗

PubMed1999

[Plasma prostaglandin E2 in pregnant women undergoing labor induction with endocervical gel application].

The authors describe an assay that quantify with precision the plasmatic prostaglandin E2 (PGE2). The aim of this study was to evaluate the effect of the gel formulation PGE2 endocervical in the induction of labour. We have studied 26 pregnant women without disease at the term of the pregnancy. The blood sample was collected before and 30 minutes after the labor induction in tubes with 10 mg EDTA Na2 and 5 microg of aspirin. The PGE2 was isolated by extraction and chromatography with 70-100% recovery. The concentration was evaluated by a completion assay with RIA. The PGE2 in plasma was found before and after the induction of labor with the following results: 347 +/- 51.6 and 719 +/- 128 pg/ml. The data was compared by the Student's t test for paired values (df = 50, t = 13. 22 and p < 0.0001). We can conclude that in pregnant women the concentration of PGE2 in plasma was double after the labor induction with the sensitivity in 1.25 pg/tube and the reproducibility 4.6% intraassay and 7% interassay showing that the method is sensitive, reproducible and efficient for the PGE2.

Administration, Intravaginal↗

PubMed1999

A unified framework for data modeling on medical information systems.

Medical Information Systems (MIS) are seen as a way of optimizing the use of existing health-care infrastructure, without resorting to new and costly hospital (re)construction. The qualitative (re)design of such an environment requires a basic understanding of patient and doctors related characteristics and capabilities. Patient care, patient education, medical education, and clinical research need to be considered to meet the basic requirements on the level of services desirable, determined on the basis of the patient's length of stay; i.e., used for modeling the significant entities of such a world. The aim is to extract conclusions for the level of services provided to the users. One's concept will capture, as well as will integrate, the basic design principles under which MIS may be set.

Artificial Intelligence↗

PubMed1998

[Significance of family assessment and biological markers in the prevention of arterial hypertension].

OBJECTIVE: To verify the predictability of the appearance of hypertension through the clinical history and biological markers. POPULATION: Consisted of 300 Portuguese Caucasian individuals, M = 130 and F = 170, between the ages 18 and 85, including 90 pregnant women. METHODS: Blood pressure was measured in every individual, and questions were made concerning personal and familiar hypertensive background. The serum renin activity, the active renin, serum endoxin, and the urinary aldosteron, free dopamine, c--AMP, and noradrenalin were checked. The analysis of the results was carried ou using the Student's T Test and de chi(2) method. RESULTS AND CONCLUSIONS: Hypertensive parents lead to the development of hypertension on their descendants; the averages of diastolic blood pressure in normotensive individuals are higher when parents are hypertensive, compared with normotensive, seeming that a possible genetic factor may be implied in the involvement of the vessels. Normotensive young masculine adultshave higher average systolic blood pressure when their fathers are hypertensive, than those whose fathers have normal blood pressure levels; as far as young women are concerned, we verified that the mother's genetic influence seems to be relevant in the appearance of higher blood pressure levels in their daughters during pregnancy, contributing to think hat man and women may have genetically different factors to determine blood pressure levels. We also verified that young adults with normal levels of blood pressure, whose parents suffer from high blood pressure, present significantly higher levels of serum renin activity than a similar group of young adults whose parents have normal blood pressure. We concluded that the family history and the measuring of the blood pressure even at young adults may contribute for the forecasting of high blood pressure, as is the evaluation of biological parameters, particularly in those who have family history of hypertension. Serum renin activity may be a possible biological marker for the forecast of the future development of high blood pressure.

Adolescent↗

PubMed1998

[Atrial fibrillation surgery using intraoperative radiofrequency].

Radiofrequency ablation is successful in most supraventricular tachyarrhythmias and the first results in percutaneous applications in atrial fibrillation have been published. At present, all the surgical techniques for the treatment of atrial fibrillation use extensive atrial incisions. A case report is presented of a 67 year old woman with chronic atrial fibrillation and rheumatic mitral and tricuspid valve disease. At surgery, pulmonary vein isolation was performed using a continuous linear ablation around the pulmonary veins, instead of using extensive atrial incisions. Concommitantly, a mitral valve replacement and tricuspid valve annuloplasty were performed. Five months after surgery, the patient remains with a stable sinus rhythm surgery and in functional class I (NYHA).

Aged↗

PubMed1997

When and how to report results of surgery on atrial fibrillation.

OBJECTIVE: Several medical, interventional and surgical techniques are used to treat atrial fibrillation, aimed at different goals and having variable success rates. To be able to assess and compare all these techniques a methodology of study and a classification is proposed. METHODS: We developed a five grade score, named the Santa Crus Score, based upon the post-operative atrial rhythm and the effective atrial contraction. Score 0 corresponds to a persistence of atrial fibrillation, the presence of a regular rhythm is grade 1, 2 or 3 if there is no atrial contraction; right atrial contraction; or bilateral atrial contraction, respectively. Score 4 corresponds to sinus rhythm and bilateral atrial contraction. Surgery for atrial fibrillation was performed on 51 patients since 1992. All patients but two had associated mitrial surgery. Three different maze techniques were performed on 17 patients and the pulmonary veins isolation procedure on 34 patients. Patients were reassessed at 1, 6, 12, 24 and 36 months. RESULTS: After the maze I procedure atrial fibrillation eradication was achieved in 88% of patients but none scored 4. Three patients changed score during the first year. All maze III patients scored 0 initially and one changed to score 3 in the first year. Sixty percent of the maze IIIA patients scored 4, but one evolved to score 0 at 6 months. The pulmonary veins isolation technique eliminated atrial fibrillation in 71% of the patients initially, and in 60% after 1 year, and achieved a score of 4 in a third of the patients. CONCLUSION: This classification considers the intermediate grades of success that can occur with absence of atrial fibrillation and is applicable to all forms of therapy.

Adolescent↗

PubMed1997

[The implantable cardioverter-defibrillator: the Portuguese experience].

OBJECTIVE: The aim of this study was to review the Portuguese experience with implantable cardioverter-defibrillator therapy (ICD), in order to evaluate the increase in the number of ICD implanted, the main indications for this kind of therapy, the technical evolution of the procedure and the results of the follow-up of these patients during the last five years. PATIENT SELECTION: The study group consists of 58 patients, 53 male and 5 female, mean age 54 +/- 14 years with ICD implanted in our country since 1992. The ICDs were implanted in 4 Hospitals, namely, Santa Cruz Hospital with 36 patients, Santa Maria Hospital with 11, Santa Marta Hospital with 8 and Coimbra University Hospital with 3 patients. Twenty six patients were resuscitated from cardiac arrest and the other 32 had ventricular tachycardia (VT) not tolerated haemodynamically and refractory to therapy. The diagnosis was coronary artery disease in 31 patients, dilated cardiomyopathy in 8, valvular disease in 4, congenital cardiopathy in 3, right ventricular dysplasia in 2, congenital long QT syndrome in 1, hypertrophic cardiomyopathy in one. Seven patients had idiopathic ventricular fibrillation without structural heart disease and one patient had isolated right ventricular dilatation. METHODS: All patients underwent electrophysiological study before ICD implantation. In 2 patients epicardial leads were used and in the remaining 56 patients a transvenous approach was used. The device was implanted in an abdominal position in 36 patients and in a pectoral position in 22. Defibrillation and pacing thresholds were measured during the implantation procedure and whenever necessary. Patients were followed up on an outpatient basis with evaluation of the number of arrhythmic episodes, therapy efficacy with reprogramming of the device when required. RESULTS: The number of implantations has increased, from 4 devices implanted in 1992, to 32 in 1996. The implantation was successful and without mortality or complications in all patients. Defibrillation threshold was 16 +/- 3 J, with an electrode impedance of 48 +/- 9 Ohms. During a mean follow-up time of 18 +/- 15 months (1 to 56) 5 patients died, one of sudden death and 4 of non cardiac deaths, 15 patients were re-admitted to hospital and in 8 patients the device was replaced due to exhaustion. In this period, 37 patients (64%) had arrhythmic episodes detected by the device, 32 patients (55%) had shocks and 9 (16%) were treated with anti-tachycardia pacing. Inappropriate shocks were observed in 10 patients (17%). The ICD were reprogrammed in 11 patients. CONCLUSIONS: Portuguese experience with IC implantation is increasing and has shown to be a safe procedure with no operative mortality or morbidity. The incidence of appropriate shocks was high with a good efficacy in sudden death reduction.

Adult↗

PubMed1997

[Reduced and oxidized glutathione of the placenta in pregnancy complicated by pre-eclampsia].

Significative enhancement of free radical formation (FRO) in vivo is an important feature of hypertensive disorders of pregnancy (HDP), namely preeclampsia (PIH). The latest investigations about the pathology of HDP, showed the contribution of placental circulation to the development and evolution of such disease. The placental bed can be a potential source of FRO or activation of cells that can produce FRO. Glutathione, is an important molecule for cellular protection against damage, is a cofactor of many enzymes, in particular, for the glutathione peroxidase of the placental tissue; this enzyme in the placenta bed prevent the production of thromboxan and lipoperoxides; the latter are potentially damaging to the endothelium cells and can cause vasoconstriction, the most important feature of PIH. The activity of that enzyme is deficient in PIH. We studied, by fluorometric assay, the concentrations of the two states of glutathione in placental homogenates (PLH) from pregnant women without pathology (PWN) and from pregnant women with PIH (PWPIH). The data showed significant low concentrations in the PLH of the two states of glutathione in the PWN against high concentrations of this molecule in the PLH from PWPIH. This feature can result from a deficient user of the glutathione by the cellular mechanism for prevention against oxidative factors. In addition, our study shows a biochemical marker that is suggestive that the placental bed is a potential source of FRO production in PIH.

Adult↗

PubMed1997

Effect of an aerobic training on magnesium, trace elements and antioxidant systems in a Down syndrome population.

The aim of the present study was to determine the effect of an aerobic training on plasma and red blood cells' levels of magnesium, copper, selenium and zinc and on some oxidative stress parameters in a Down syndrome (DS) sample population. Sixteen young male adults with DS participated in the protocol. Among them, eight were randomly assigned to the control group and the remaining eight participated in a 16 week training programme consisting of 10 min warm-up followed by an aerobic session at a work intensity of 60 to 75 per cent of VO2 peak lasting from 15 to 25 min, increasing 5 min every 5 weeks and by a 5 min cool-down period, 3 days/week. Blood was withdrawn by butterfly from antecubital vein of each subject at fast, 2 days before the beginning of the programme and 2 days after its ending. Before the training period, when comparing the two groups, no significant differences were observed in the evaluated parameters. However, when comparing with a healthy population, red blood cells magnesium and plasma and red blood cells selenium mean values were low in both groups and mean SOD activity was 1.4 times higher. After the protocol the mean values of the minerals studied did not show significant differences between groups except for plasma zinc that was lower (p = 0.029) in the trained group. Plasma TBARS increase was significant in the trained group (p = 0.034) but not in the control group and plasma GSH of the trained group had a significantly higher increase than the control group (p = 0.003). The levels of plasma TBARS after the training programme that were inversely correlated with red blood cells GSSG levels (p = 0.023) and the higher increase of plasma GSH mean values observed, may be explained by the effect of the exercise period on the peroxidation and reduction of glutathione and also on the synthesis and efflux of GSH. Red blood cells magnesium levels remained low after the training programme which is in accordance with other studies. Plasma zinc decreased during the programme could be related to the activated expression of antioxidant mechanisms after the training.

Adolescent↗

PubMed1997

Longstanding traumatic tricuspid regurgitation with severe right ventricular failure.

A very unusual case of traumatic tricuspid regurgitation is reported, with severe symptoms of right ventricular failure, extreme dilatation of the right heart, echocardiographic and angiographic criteria of major tricuspid regurgitation, and severe right ventricular systolic dysfunction. The patient was referred for heart transplantation, on the assumption that conventional surgery was not possible. After careful evaluation, as the patient had normal pulmonary artery pressure and resistance, a tricuspid valve was replaced with good surgical outcome.

Accidents, Traffic↗

PubMed1996

Pathogenetic factors of acute schistosomiasis mansoni: correlation of worm burden, IgE, blood eosinophilia and intensity of clinical manifestations.

A clinical study of 34 previously healthy young patients simultaneously infected in an endemic area of schistosomiasis mansoni is presented, emphasizing the initial phase of the infection. Its intensity was established according to the occurrence, intensity, and duration of the signs and symptoms in order to investigate the possible correlations between the worm burden (estimated by the number of eggs in faeces), the blood eosinophilia and specific levels of IgE (estimated by the area of immediate intradermal reaction), with the clinical manifestations. A significant but low-level association was found between the worm burden and morbidity, suggesting that multiple factors, besides worm burden itself, may contribute to the pathogenesis of the disease.

Acute Disease↗

PubMed1996

[Implantable cardioverter-defibrillators in patients resuscitated from sudden death and in patients with sustained refractory ventricular tachycardia].

OBJECTIVE: The aim of this study was to evaluate the results of our experience with implantable cardioverter-defibrillator therapy. PATIENT SELECTION: We treated with implantable cardioverter-defibrillator (ICD) 18 patients, 15 male and 3 female, mean age 51 years, ranging from 12 to 76 years, with life threatening ventricular arrhythmias. Eleven patients were resuscitated from cardiac arrest and seven had refractory ventricular tachycardia. The underlying condition was coronary artery disease in 12 patients, dilated cardiomyopathy in two, congenital long QT syndrome in one, mitral regurgitation in one and idiopathic in two patients. METHODS: All patients underwent cardiac catheterization and electrophysiological study before ICD implantation. In the first patient epicardial leads were used, but a transvenous approach was used in the remaining 17 patients. The device was implanted in an abdominal position in all patients. Defibrillation and pacing threshold tests were performed during the implantation procedure and whenever necessary. After implantation, patients were followed up in an outpatient basis, with evaluation of therapy efficacy and reprogramming of the device if required. The mean follow-up time was 16 months, ranging from 1 to 40 months. RESULTS: The implantation was successful and without complications in all patients. Defibrillation threshold was considered within normal range, with an electrode impedance ranging from 40 to 65 Ohms. During the follow-up period no deaths occurred, 8 patients (44%) had episodes of VT or VF that were successfully treated, with shock in six patients, with antitachycardia pacing in one and with both modalities in another patient. Inappropriate shocks were observed in three patients (16%). The device was reprogrammed in five patients. CONCLUSIONS: Our experience with implantable ICD in patients who survived cardiac arrest or with refractory VT has shown a low surgical risk with no mortality. The incidence of ICD discharges was high, with a satisfactory efficacy rate and the number of inappropriate shocks was acceptable. The careful patient selection made possible a good cost/benefit relation.

Adolescent↗

PubMed1996

[Exertion syncopal crisis in the young, associated with idiopathic long QT syndrome].

The cases of two young patients with repetitive syncopal attacks due to idiopathic long QT syndrome (ILQTS) are reported. Both had been primarily misdiagnosed for seizures. In one of the cases the QT interval in the ECG at rest was normal. The same patient had a previous episode of cardiac arrest with ventricular fibrillation. The treadmill stress test was of great value, revealing polymorphic ventricular tachycardia induced by exercise, and evaluating the efficacy of beta-blocking therapy in the follow-up. The ILQTS should be considered a possible etiology in any patient presenting with new onset seizures, especially in the young. The treatments were different in both cases. In the first one, the treatment with nadolol (100 mg od) revealed to be very effective with total remission of symptoms. The treadmill stress test performed 15 days after the beginning of treatment did not show any ventricular arrhythmias, and it was assumed that the patient was effectively protected against ventricular arrhythmias. After 4.5 months of follow up, no syncopal episodes occurred. In the second case due to young age, the frequency, and the severity of the attacks (cardiac arrest with ventricular fibrillation), and the inefficacy of beta-adrenergic-blocking agents, the implantable cardioversor-defibrillator was the treatment chosen, although the beta blocking therapy was maintained to reduce the number of arrhythmic events. The ILQTS is a rare anomaly related to sudden cardiac death. The ILQTS is characterised by the association of several distinctive electrocardiographic features, among which prolongation of the QT interval is the best known. Life-threatening arrhythmia occurs usually under conditions of physical or psychological stress. Relatively effective therapies do exist and are represented by antiadrenergic interventions: beta-adrenergic-blocking agents are the treatment of choice. When they fail, left sympathetic denervation or the automatic implantable cardioversor-defibrillator have also proved to be effective.

Adult↗

PubMed1996

[Anomalous insertion of mitral papillary muscles in obstructive hypertrophic myocardiopathy. Report of 2 cases].

Hypertrophic obstructive cardiomyopathy is a pathologic entity whose features are complex and diverse. Its surgical treatment generally requires myectomy. When the left ventricle outflow gradient is also due to mitral valve abnormalities, mitral valve replacement has been considered as the treatment of choice for the relief of the obstruction. We report two cases in which transesophageal echocardiography has allowed a good definition of this complex area of the heart and a better diagnosis and treatment of its components. Its use led to the diagnosis of abnormal papillary muscles inserted directly in the anterior leaflet of the mitral valve, with severe left ventricle outflow obstruction. Surgical treatment consisted of septal myectomy and excision of the muscles, thus preventing the need for mitral replacement. Systolic anterior motion of the mitral valve subsided and the outflow gradients became negligible. This new approach for the treatment of hypertrophic obstructive cardiomyopathy will be of benefit for patients in whom the anomalous insertion of the papillary muscles are recognized before surgery, thus preventing mitral valve replacement.

Adult↗

PubMed1995

Histologic and genetic assessment of explanted allograft valves.

A possible way of analyzing the immune response triggered by the allograft and the cellular viability is to compare immunocompetent and immunosuppressed patients, such as those having valve replacement and heart transplantation, respectively. These groups differ in immunosuppression therapy, preparation methods, valve hemodynamics. In the present study, we investigated polymerase chain reaction-amplified DNA flanking hypervariable (CA)n regions obtained from valve leaflets taken from patients having valve replacement or heart transplantation and performed a histologic analyses of the cells. In addition, we assessed an autograft valve to compare the hemodynamic effects on the cellular composition of the valve leaflet. We conclude that leaflet cellularity of the heart transplantation and autograft patients is superior to that of the valve replacement patients. These differences were consistent with the occurrence of an immune response in the valve replacement group, which was prevented or abrogated by immunosuppressive therapy administered to the heart transplantation group. However, it cannot be excluded that preparation procedures have a long-term effect on the extracellular matrix, leading to deterioration of cell adhesion and homing conditions.

Adult↗

PubMed1995

Atrioventricular valve repair using externally adjustable flexible rings.

Initial results obtained with a new flexible ring, adjustable from outside of the heart after interruption of extracorporeal circulation, are presented. Twenty-five rings have been inserted in 20 patients, 14 in the mitral position and 11 in the tricuspid position. In 8 of the 14 patients receiving mitral annuloplasty, other standard mitral valve repair techniques were used. Adjustment, assisted by intraoperative transesophageal color Doppler echocardiography, was done for 10 (71%) of the mitral rings and for 8 (73%) of the tricuspid rings. Residual mitral regurgitation disappeared or became minimal in 9 (90%) patients, and a mild regurgitation remained in 1. In all patients who received tricuspid rings regurgitation was abolished after the adjustment. There was no hospital or late mortality. After a maximum follow-up of 6 months results are comparable in the tricuspid and mitral positions and echocardiographic evaluation revealed stable competent valves in all patients but one, who underwent reoperation because of failure of a mitral valve chordae shortening procedure. The use of externally adjustable rings for the mitral and tricuspid valves is a safe alternative for atrioventricular valve annuloplasty and has the additional advantage of reducing postrepair regurgitation.

Adolescent↗

PubMed1995

The allograft valve in heart transplantation and valve replacement. Genetic assessment of the origin of the cells by means of deoxyribonucleic acid profiles.

Assessment of the cellular origin of allograft valves is essential in comprehending their biologic behavior and in improving preparation methods. In this study we retrospectively analyzed 10 allografts obtained from patients who underwent valve replacement or heart transplantation. Histologic evaluation and deoxyribonucleic acid amplification by polymerase chain reaction technology with fluorescence labeled primers was performed on different parts of the valve leaflets. Automated analyses of the obtained amplimers showed in the heart transplantation group the presence of receptor cells interspersed with native donor cells in three cases. Preliminary results for the valve replacement group are inconclusive as yet.

Adult↗