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Biomedical subjects

H Guimarães

Publications and source records attributed to H Guimarães.

At least 19 recordsLinked to original sources

Neonatal perforation of a Y-shaped sigmoid duplication.

Tubular colonic duplications are exceedingly rare; the "Y"-shaped forms are exceptional. In the absence of associated low vertebral or urogenital malformations (often fistulas), the tubular colonic malformations frequently stay hidden for several years until a complication develops. The authors report a case of a spontaneous perforation of a Y-shaped tubular colonic duplication during the neonatal period.

Anastomosis, Surgical↗

Ebstein's anomaly in neonates.

Ebstein's anomaly is a rare congenital heart disease abnormality in which the tricuspid valve leaflets do not attach normally to the tricuspid valve annulus. The effective tricuspid valve orifice is displaced apically into the right ventricle (RV), near the junction of the inlet and the trabecular parts of the RV. The authors present a retrospective study of the patients with Ebstein's anomaly admitted to a neonatal intensive care unit, in the period between January 1993 and March 2000. There were ten patients, representing 0.24% of total neonates and 1.99% of total congenital heart disease admitted to the institution in the same period. Fifty per cent were male and only one case had prenatal diagnosis. Holosystolic murmur (100%) from tricuspid regurgitation and cyanosis (80%) were the most frequent clinical findings. Chest X-ray was abnormal in 90% of the neonates, with a "balloon-shaped" enlarged heart. The main electrocardiographic findings were right atrial enlargement (70%) and arrhythmias (40%). Apical displacement of the septal leaflet of the tricuspid valve, to a maximum of 20 mm, and leaflets tethering to underlying RV myocardium were found in all patients. Tricuspid valve regurgitation was found in 90% (severe form in four cases). An atrial intracardiac shunt, mostly right-to-left, was also found in 50%. Digoxin was used (40%) to restore sinus rhythm. Fifty per cent of the neonates received intravenous prostaglandins. Two patients required a surgical procedure. Two patients died in the neonatal period. During the follow-up period (range 0.3-74.6 months), only one episode of supraventricular tachycardia was recorded. At present seven patients are clinically stable, three of them on medication.

Child↗

Cardiac rhabdomyomas presenting in neonates.

UNLABELLED: Rhabdomyoma is the most common cardiac neoplasm in neonates. Spontaneous regression of such tumors is common, particularly with smaller lesions, followed by resolution of symptoms. Because most of the tumoral masses regress spontaneously, treatment should primarily be symptomatic, while surgical removal is required only in life-threatening situations. Tuberous sclerosis is found in half of the patients with rhabdomyomas. AIM: The aim of our work was to analyze the cases of rhabdomyoma with neonatal presentation in our hospital. METHODS: A retrospective review was performed of the hospital records (cardiovascular examination, radiologic and echocardiographic findings, association with tuberous sclerosis, treatment and follow-up) of all neonates admitted, during the last 12 years, with the diagnosis of rhabdomyoma. RESULTS: Six patients were found. All diagnoses were established during the first month of life. One third of our population had associated tuberous sclerosis. In three cases the tumors were multiple and the preferential location was the left ventricle. In only one case was surgical removal indicated because of the presence of life-threatening symptoms but the infant's parents refused consent for the procedure. All the children had regression of the tumoral masses. CONCLUSIONS: The natural history of rhabdomyomas is one of spontaneous regression with surgical excision being recommended only in the presence of life-threatening symptoms.

Heart Neoplasms↗

Prenatal diagnosis of abdominal enteric duplications.

Alimentary tract duplications are rare congenital malformations with few reports of the antenatal sonographic appearance. Early diagnosis is of paramount importance to prevent complications. We present a case of a cystic gastric duplication diagnosed antenatally at 31 weeks' gestation, which was treated successfully. Simultaneously, we review all published cases of prenatally diagnosed enteric duplications.

Adult↗

Repolarization abnormalities after catheter ablation of differently located overt accessory pathways.

PURPOSE: Electrical repolarization abnormalities are usually seen after radiofrequency catheter ablation in overt accessory atrio-ventricular pathways. These abnormalities have been recognised as "cardiac memory". The aim of this study was to assess the relationships between electrical repolarization abnormalities and the location of the accessory atrioventricular pathway in the atrio-ventricular junction. We also assessed the relationship between electrical repolarization abnormalities and the degree of ventricular preexcitation. MATERIAL AND METHODS: Our group consisted of 45 patients with overt and persistent preexcitation who were successfully submitted to radiofrequency catheter ablation. Mean age was 38.9 +/- 14.9 years (14 to 64), 28 of whom (62.2%) were male and 17 (37.8%) female. The location of accessory pathways the was left lateral in 14 patients, right posteroseptal in 14 patients, right mesoseptal in eight patients, right anteroseptal in four patients and other locations in the remaining four. Surface electrocardiograms were performed immediately following ablation, 24 hours later and three or more months after the procedure. RESULTS: T wave abnormalities (flattened, inverted or peaked) were detected on the first day in 51% of patients, being more frequent after right accessory pathway ablation (86.9% versus 13.1% in left accessory pathways). These electrocardiographic changes were particularly frequent in patients with right mesoseptal (5/8, 62.5%) and posteroseptal (13/14, 93.3%) pathways, of which 62.5% and 71.5%, respectively, showed marked preexcitation before ablation. These findings were significantly different from those observed in patients with left lateral pathways--only 35.7% showed marked preexcitation and only two of fourteen patients (14.3%) presented T wave abnormalities after ablation. After the third month, most of the patients that had undergone successful ablation presented completed electrocardiographic normalization. CONCLUSIONS: Patients undergoing radiofrequency catheter ablation for right accessory pathways show more frequently repolarization abnormalities than those submitted to ablation of the left lateral accessory pathways. The occurrence of these changes after preexcitation resolution may depend on the degree of previous preexcitation.

Adolescent↗

Neonatal cerebral Doppler: arterial and venous flow velocity measurements using color and pulsed Doppler system.

OBJECTIVE: To contribute to the establishment of reference values of blood flow velocity assessed by cerebral Doppler in healthy infants related to gestational age and birth weight during the first week of life. METHODS: Five arteries and three veins were evaluated respectively in 120 (74 premature) newborns and in 100 (70 preterm) infants. In a quarter of the latter three recordings at 5-minute intervals were made to assess reproducibility. The relation between flow measurements and gestational age was assessed by linear regression, means by analysis of variance (or Kruskall-Wallis test) and paired samples by Student's t test. RESULTS: There was a significant increase of arterial velocities with increasing gestational age and birth weight, but not for venous velocities. Significant higher values were found in the internal carotid artery followed by the medium cerebral artery. The venous velocities were highly reproducible and the main patterns observed were bandlike and sinusoid type. CONCLUSION: The knowledge of normal cerebrovascular physiology is essential to understand the pathogenesis of neonatal brain damage and can help pediatricians in an accurate interpretation of the flow profile in neurological pathology.

Arteries↗

[Patent ductus arteriosus in neonatal intensive care].

OBJECTIVE: In this study we evaluated the prevalence of symptomatic patent ductus arteriosus (PDA) in newborns, admitted to a neonatal intensive care unit (NICU), as well as the clinical features and the outcome of medical or surgical treatment. METHODS: We carried out a retrospective medical chart review of 42 newborns admitted to an NICU between May 1996 and May 1998. Data regarding birth weight, sex, gestational age, prenatal corticotherapy and surfactant needs were gathered. Clinical evolution was assessed based on mechanical ventilation, morbidity and mortality. The therapeutic options and their results where analysed. RESULTS: Of the 1,195 newborns admitted to an NICU, 42 had symptomatic PDA. The prevalence was higher in newborns with a low birth weight. There was no significant difference regarding the administration of steroids prenatally in the newborns with PDA compared to the remaining newborns without PDA. Surfactant therapy, mechanical ventilation, bronchopulmonary dysplasia, necrotizing enterocolitis and intraventricular hemorrhage were found to be more frequent in patients with PDA, especially among those with a lower birth weight, with statistical significance for newborns weighing less than 2,500 g (p < 0.05). The therapy most frequently used was indomethacin, with a success rate of 22/23 (95.6%) and with two cases of acute renal failure as side effects. Only one infant required surgical ligation of PDA. Mortality was similar in both groups (PDA vs. no PDA). CONCLUSION: PDA was probably underdiagnosed in our NICU. Morbidity, but not mortality, was higher in newborns with symptomatic PDA. We conclude that treatment with indomethacin is preferred to surgical ligation as an initial approach in those infants. Our data show the importance of early screening with echocardiogram for "silent" PDA in low birth weight neonates.

Birth Weight↗

Does umbilical vein catheterization to exchange transfusion lead to portal vein thrombosis?

UNLABELLED: The aetiopathology of extrahepatic portal vein obstruction is unknown. In retrospective studies, umbilical vein cannulation and sepsis have been alleged to cause portal thrombosis. This prospective study was undertaken to detect whether thrombosis and consequent obstruction of the splenoportal venous system develops after umbilical vein catheterization for exchange transfusion in newborns using Doppler ultrasound. Forty children (M = 24; F = 16) who had undergone exchange transfusion for hyperbilirubinaemia were studied at school age. Maximal duration of the venous umbilical cannulation was 120 min and sepsis did not occur. Clinical, biological and sonographic examinations were normal, except in 3 children. In 2 the left branch of portal vein could not be identified (normal variant). CONCLUSION: Our results show that, in these children, umbilical vein catheterization did not lead to development of portal vein thrombosis. However, when other risk factors such as umbilical infection, traumatic catheterization are associated, children should be screened for obstruction of the portal vein.

Child↗

Dyssegmental dysplasia: a case report of a Rolland-Desbuquois type.

Two different forms of dyssegmental dysplasia, mild and severe, can be distinguished on clinical, radiographic and chondro-osseous morphologic grounds. The milder Rolland-Desbuquois type is frequently characterised by survival beyond the newborn period. The lethal Silverman-Handmaker type has distinctive and more severe findings. In this paper, a rare case of the Rolland-Desbuquois type is presented. The case is unusual because although it was the milder form, the child died on the 10th day of life.

Abnormalities, Multiple↗

[The noise in neonatal intensive care units].

BACKGROUND: Noise constitutes a significant problem in Neonatal Intensive Care Units (NICU) because of its potential deleterious effects on the newborn patients and staff. The aim of this study was to evaluate the degree of noise in the NICU of Hospital S João, Oporto, in order to identify its origin and possibility of reducing it. MATERIAL AND METHODS: Measurements of noise were made for 24 hours, between 13 and 14 June 1994, in five different locations inside the NICU, using a slow time constant sonometer. RESULTS: The surrounding noise level changed between 61 and 67 dB (A), with spikes over 100 dB (A). CONCLUSIONS: Our results were similar to those previously reported in the literature. The following measures to reduce the level of noise were taken: 1) reduction of alarm sounds to minimal safe level; 2) replacement of doors; 3) instructions to visitors and staff.

Humans↗

[Pulse wave velocity as expression of arterial compliance and its importance in the evaluation of arterial hypertension].

STUDY OBJECTIVE: To determine the arterial compliance through the evaluation of pulse wave velocity. DESIGN: Open study with direct comparison of different groups within a 12 week evaluation period. PATIENTS: 69 patients, 49 with hypertension and 20 normals individuals. INTERVENTIONS: Different groups with the following treatments: Isradipine, Lisinopril, Dilevalol and no therapy. MEASUREMENTS AND MAIN RESULTS: There is marked differences in the pulse wave velocity when hypertensive patients are compared with normal individuals (p < 0.001). In a 12 week therapeutic evaluation there is an improvement in the pulse wave velocity particularly when the arterial pressure was lowered to normal values in the hypertensive patients: Lisinopril (p < 0.005), Isradipine (p < 0.005), Dilevalol (p < 0.025). CONCLUSIONS: It is very easy to evaluate the pulse wave velocity. Arterial compliance, which may be evaluated using the pulse wave velocity, is significantly reduced in hypertensive patients, compared with age-matched control subjects. The use of antihypertensive drugs is associated with changes in arterial compliance. There is a significant decrease in the pulse wave velocity after the administration of ACE inhibitors, calcium channel blockers and beta blockers for an equivalent fall in blood pressure. These observations emphasizes the potential importance of the changes in the large arteries, considered as either an associated factor or a consequence of elevated blood pressure, in the evaluation of the cardiovascular morbidity, and mortality of patients treated for hypertension.

Adult↗

The normal values of spatial velocity in the second part of QRS (a cooperative study of 229 healthy individuals).

The Spatial Velocity (SV) represents the inscription velocity from spatial vectors of the QRS loop. According to Sano, this parameter has revealed a diagnostic capacity for some well defined pathologies. Using Hellerstein and Hamlin's formula, the SV has been determined from the orthogonal Frank leads in a 250 mm/sec recording. Using Simonson's criteria, 229 normal individuals, arranged in seven groups according to age and sex, were used in an attempt to get normal values for the second half of the QRS loop. SV was determined in six time intervals of 2.5 msec from the 25 msec vector before the end of QRS. We found significant difference between the values obtained from each time interval, except in the 35--37.5 msec and 37.5--40 msec vectors. On the other hand, no significant differences were found among the normal individual groups. The 96th percentile distribution was used to get the normal extreme values in the entire group of individuals.

Adult↗