Search PubMed⌕ Search

Biomedical subjects

A Davignon

Publications and source records attributed to A Davignon.

At least 73 records · Page 4Linked to original sources

Isovolumic contraction time of right ventricle in d-transposition of great arteries.

The pre-ejection period of the right ventricle in d-transposition of the great arteries is known to be prolonged, compared with the same interval of the left ventricle of normal subjects. In the present study, the echocardiographic measurement of the components of the pre-ejection period of the right ventricle of 14 patients with d-transposition of the great arteries shows that the isometric contraction time of the right ventricle in d-transposition of the great arteries is similar to the same interval calculated on the left ventricle of 76 normal children of comparable age. On the other hand, the electromechanical delay was significantly greater for the right ventricle of d-transposition of the great arteries than for the left ventricle of the normal subjects. It is concluded that the prolonged pre-ejection period of the right ventricle in d-transposition of the great arteries is not the result of right ventricular dysfunction but solely of a longer electromechanical delay.

Adolescent↗

Effects of hemodialysis on myocardial function in pediatric patients.

The effect of hemodialysis on myocardial function in 10 pediatric chronic hemodialysis patients was assessed utilizing echocardiography. Parameters of cardiac function were measured prior to and immediately after dialysis. A significant decrease in cardiac output was observed post-dialysis. Unlike that observed in adult patients a real improvement in myocardial function as indicated by an increase in the mean velocity of circumferential fibre shortening was evident post-dialysis.

Acetates↗

[Aneurysm of the ductus arteriosus. Apropos of case operated on with success].

A 6 week old baby was operated on successfully for removal of an aneurysm of the ductus arteriosus. The aneurysm, absent at the age of 12 days, developed progressively during the closure of the ductus. The only suggestive symptom was a haemoptysis. The radiological appearances were characteristic. The authors discuss the physiopathology, clinical presentation and radiological appearances of this lesion.

Ductus Arteriosus, Patent↗

Echocardiographic manifestations of persistence of the right sinus venosus valve.

The echocardiographic features of a neonate born with a persistent right sinus venosus valve are presented. Because surgical correction of this serious anomaly may be possible, the diagnosis should be made soon after birth. An echocardiogram suggesting a right atrial myxoma, an unlikely finding in a neonate, should be an important clue to the diagnosis of this anomaly.

Echocardiography↗

Assessment of Brescia-Cimino fistula blood flow rates in pediatric patients.

Blood flow rates were measured using an isotopic dilution method in the main drainage segments of Brescia-Cimino arteriovenous fistulas in 9 pediatric patients who had undergone successful renal transplantation, 3 patients on hemodialysis and 2 patients with end-stage renal disease. Blood flow rates varied from 68 to 882 ml/min. The possibility that such high flow rates may have deleterious effects on limb growth, cosmetic appearance and cardiac function without any benefit to the patient is discussed.

Adolescent↗

Evolution of QRS-T relationship from birth to adolescence in Frank-lead orthogonal electrocardiograms of 1492 normal children.

Patterns of evolution of QRS-T relationship were investigated by determining statistical distributions of QRS and STT integral vectors and the ventricular gradient vector in 1492 normal children divided into 12 age groups from birth to the age of 16 years. From birth to the age of 4 days, the ventricular gradient vector shifts posteriorly and to the left due to posterior shift of the STT integral vector and an increase in the spatial angle between QRS and STT integral vectors to a mean value of 103 degrees. These early neonatal changes in QRS-T relationship probably reflect the sudden reduction of hemodynamic load and the subsequent postnatal atrophy of the right ventricle while the left ventricular load slowly increases. The magnitude of the ventricular gradient vector increases from age 3 weeks until about 7 years. The increase appears to be related to a gradual increase in the magnitude of the QRS and STT integral vectors and a drastic decrease in the spatial angle between them. The spatial angle between QRS and STT integral vectors reaches it minimum (22 degrees) in the age group 1.5--4.5 years, suggesting that at that age the average direction of ventricular excitation and repolarization wavefronts are nearly opposite to each other. In addition to the shifting balance between the left and right ventricular hemodynamic load, other factors, such as the maturation of the sympathetic nervous system, may be important in determining spatial gradients in the duration of action potentials, thus influencing the relationship between ventricular excitation and repolarization.

Action Potentials↗

The effects of Brescia-Cimino fistulas and cardiac function in transplanted pediatric patients.

The cardiac hemodynamic effects of patent Brescia Cimino fistulas were assessed using non-invasive techniques in 10 pediatric patients who had undergone successful renal cadaveric transplantation. All had hemoglobin levels above 11 g/dl and had serum creatinine values of less than 1.5 mg/dl. Studies were done prior to and after temporary fistula occlusion to assess the effect of fistula patency on parameters of cardiac function. Values obtained prior to fistula occlusion were compared to those obtained in a normal control population. It was noted that though fistula patency did significantly alter cardiac function, changes were such that fistula patency could be safely maintained. It was also noted that the difference in cardiac index prior to and after occlusion provided a good assessment of fistula flow.

Adolescent↗

[Hypoplastic syndrome of the left heart. Anatomo-echocardiographic correlations].

The findings on echocardiography and their anatomical correlations are reported in a group of 15 neonates with the syndrome of hypoplasia of the left side of the heart. The lesions which make up this syndrome could be defined precisely using echocardiography. In the major forms of this syndrome (10 cases), the correlation between the clinical and the echocardiographical findings was sufficient to establish the diagnosis, and to avoid the necessity for cardiac catheterisation without prejudice to the treatment plan. Characteristic findings in the major types were: --an aortic diameter less than or equal to 5 mm; --a left ventricle which was absent or had a diameter of less than 11 mm with an LV/RV ratio of less than 0.6; --a mitral valve which was absent or had a very abnormal form with multiple echoes. The differential diagnosis on echocardiography and the limitations of the method are discussed.

Diagnosis, Differential↗

Simple d-transposition of the great arteries. Results of early balloon septotomy followed by two-stage surgical correction.

The follow-up of 44 patients with simple d-transposition of the great arteries is presented. All had balloon atrial septotomy shortly after birth. If an operation was needed at or before one year of age, atrial septectomy was carried out. Correction was done between the ages of 19 and 64 months. Of the 44 patients, 34 (77 per cent) are living and doing well (27 after the Mustard procedure), 3 (7 per cent) are lost to follow-up, and 7 (16 per cent) are dead. Death was due to technical problems during initial catheterization and balloon septotomy in 2 patients, occurred after septectomy in one (3 per cent), and after the Mustard procedure in one (4 per cent). There was one sudden inexplicable death in a 1 1/2-month-old patient, and 2 patients died with pulmonary vascular obstructive disease. Because of the relatively low over-all mortality and morbidity and the low surgical mortality rate for both palliation and correction, we believe that two-stage surgical correction of transposition of the great arteries is preferable to early one-stage correction in the infant.

Child↗

Cardiological signs and symptoms in Friedreich's ataxia.

The cardiovascular signs and symptoms were recorded in 36 patients with typical Friedreich's Ataxia (Group Ia, Ib). Seventeen patients were asymptomatic and this did not correlate with the severity of the disease. No pathognomonic clinical constellation was found to reveal the underlying cardiomyopathy.

Adolescent↗

Echocardiographic findings in Friedreich's ataxia.

Echocardiographic examination of 21 patients with Friedreich's ataxia (age 7 to 28 years) showed cardiac abnormalities in 90% of the cases. They were characterized by varying degrees of septal hypertrophy in 81%, left ventricular free wall hypertrophy in 61%, and a slight reduction of left ventricular internal dimension in 57% of the cases. Asymmetric septal hypertrophy (ASH) with a septal/left ventricular free wall ratio of over 1.3 was found in 29% of the cases, and systolic anterior motion (SAM) of the mitral valve in three patients. Two other patients showed evidence of a different type of cardiomyopathy with marked symmetric left ventricular hypertrophy and marked left ventricular enlargement.

Adolescent↗

Hemodynamic findings in Friedreich's ataxia.

Thirteen patients with classical Friedreich's ataxia underwent cardiac catheterization with recordings of retrograde cardiac pressures, measurements of cardiac output and calculation of the left ventricular volumes and mass. The cardiomyopathy in Friedreich's ataxia falls into the hypertrophic group of cardiomyopathies with decreased compliance of ventricular myocardium, varying degrees of concentric and asymmetric hypertrophy and outflow tract obstruction. Although there is no clear parallel between the degree of abnormal hemodynamic findings and the degree of neurological impairment, severely handicapped patients may present a diffusely hypertrophied and hypokinetic left ventricular myocardium.

Adolescent↗

Cardiac angiographic findings in Friedreich's ataxia.

Angiograms of 12 patients with typical Friedreich's ataxia were analyzed. The results corroborate previous reports and justify the conclusion that the cardiomyopathy is of the hypertrophic type. In 10 of 12 cases, the hypertrophy is concentric, and non obstructive. Less frequently (2 cases), this hypertrophy is accompanied by diffuse hypokinesis and depressed ejection fraction.

Angiocardiography↗