PubMed Health⌕ Search

Biomedical subjects

M R De Leval

Publications and source records attributed to M R De Leval.

14 recordsLinked to original sources
PubMed2001

Subdiaphragmatic venous hemodynamics in the Fontan circulation.

OBJECTIVE: We investigated the subdiaphragmatic venous physiology in patients subjected to the Fontan operation to understand some of the early and late problems of this circulation. METHODS: Flows were evaluated by Doppler ultrasonography in the subhepatic inferior vena cava, hepatic vein, and portal vein during respiratory monitoring and with a tilt table. Twenty control subjects (group A) and 56 patients who had the Fontan operation, 27 in functional class I (group B) and 29 in class III or IV (group C), were studied. Inspiratory/expiratory flow ratio was calculated to reflect respiratory effects, and upright/supine flow ratio was calculated to assess gravity effects. Inferior vena caval, hepatic venous, and wedged hepatic venous pressures were measured during catheterization in 21 control subjects and 25 Fontan patients. The difference between wedged and hepatic venous pressures represents the transhepatic venous pressure gradient. RESULTS: Fontan hepatic venous flow depended more on inspiration than control, but without difference between groups B and C (inspiratory/expiratory flow ratios: 1.7, 2.9, and 2.9, respectively; P <.02). Normal portal venous flow was higher in expiration; this effect was lost in group B and reversed in group C (inspiratory/expiratory flow ratios: 0.8, 1.0, and 1.3; P <.0005). Gravity reduced portal venous flow in groups A and B, but progression to functional class III or IV (group C) exacerbated this effect (upright/supine flow ratios: 0.8, 0.7, and 0.5; P <.01). Inferior vena caval, hepatic venous, and wedged hepatic venous pressures (in millimeters of mercury) in the Fontan groups were all elevated compared with the control group (inferior vena cava, 14.4 +/- 4.4 vs 5.9 +/- 2.3; hepatic vein, 14.7 +/- 4.5 vs 5.9 +/- 1.9; wedged hepatic vein, 14.7 +/- 4.0 vs 8.3 +/- 2.6; P <.0001). However, transhepatic venous pressure gradient in the Fontan group was lower than in the control group (0.5 +/- 0.5 vs 2.4 +/- 2.0; P <.001). Univariate analysis of inferior vena caval pressure and transhepatic venous pressure gradient showed significant inverse correlation (r = 0.6, P <.002). CONCLUSIONS: In patients who are in functionally poorer condition after the Fontan operation, portal venous flow loses normal expiratory augmentation and adverse gravity influence is enhanced. These suboptimal flow dynamics, coupled with higher splanchnic venous pressures and lower transhepatic venous pressure gradients, suggest that hepatic sinusoids are congested, acting as "open tubes." Transhepatic gradient loss is incrementally worse with higher caval pressures. These observations may be responsible for late gastrointestinal problems in patients who have had the Fontan operation.

Adolescent↗
PubMed1998

Differential distribution of angiotensin AT2 receptors in the normal and failing human heart.

Cardiac expression of angiotensin II (Ang II) AT1 and AT2 receptor subtypes is species dependent, and changes in their relative proportion may influence myocardial hypertrophy and fibrosis. Regional differences in the distribution of Ang II receptors in the normal and failing human heart were assessed using 125I-(Sar1,Ile8)Ang II binding and quantitative autoradiography. Receptor subtypes were distinguished by their affinity for selective nonpeptide antagonists (losartan and PD123319) and sensitivity to dithiothreitol. Ventricular and atrial tissues displayed a heterogeneous distribution of ligand binding sites. AT2 receptors predominated, representing 70% to 77% of the sites in normal and noninfarcted myocardium. Endocardial, interstitial, perivascular and infarcted regions in the ventricles of patients with end-stage ischemic heart disease or dilated cardiomyopathy exhibited a significantly greater density (P < .001) of high affinity AT2 binding sites (Kd = 0.57 nmol/liter) compared with adjacent noninfarcted myocardium. Regions displaying the relative increase in AT2 binding sites corresponded to areas of fibroblast proliferation and collagen deposition, shown by picrosirius red staining. AT1 binding sites were localized to nerves, occurred at relatively low density in coronary vessels and represented only 23% to 29% of myocardial 125I-(Sar1,Ile8)Ang II binding sites. The border zone between infarcted and noninfarcted myocardium characteristically contained numerous microvessels, exhibiting perivascular AT2 receptors and endothelial angiotensin converting enzyme activity, as demonstrated by binding of 125I-351A. Specific myocardial AT2 receptor mRNA transcripts (approximately 3 kb) were identified and exhibited alternative splicing of untranslated 5' exons. The differential distribution of cardiac Ang II receptor subtypes and selective increase in binding to AT2 sites in the diseased heart suggest that cells bearing the AT2 receptor represent a significant target for Ang II, possibly contributing to its growth-related actions.

Adolescent↗
PubMed1981

Calcified left ventricular aneurysm in a 6-year-old Caucasian boy.

A 6-year-old Caucasian boy presented with a calcified left ventricular aneurysm of unknown aetiology. Aneurysmectomy was carried out uneventfully. A review of the English language papers reveals that this is the first reported case of a calcified left ventricular aneurysm occurring in a Caucasian child.

Calcinosis↗
PubMed1981

[Indications to the surgical treatment of patients with "simple" transposition of the great arteries. Analysis of 302 cases surgically treated according to mustard's technique (author's transl)].

Between January 1965 and December 1979, 302 patients underwent Mustard's operation for "simple" transposition of the great arteries (TGA). 31 cases who underwent Senning operation for "simple" TGA and 7 patients with "simple" TGA and severe pulmonary vascular disease, in whom Mustard's operation was performed and a ventricular septal defect created, have not been included in the present series. The patients analysed ranged in age from 3 days to 17 years (mean = 27,6 months) and in weight from 2.7 to 40 Kg (mean = 9.9 Kg). The technique originally described by Mustard was used, with some technical modifications. There were 26 early deaths (early mortality rate = 9%). The hospital mortality was 16% during the period 1965-1969, 75% between 1970 and 1974, while during the last 5 years it was 6%. The hospital mortality was lower among the infants between 6 and 12 months of age (6%), compared with an early mortality rate of 11% among those younger than 6 months and 9% in the age group over 1 year. There were 34 late deaths (12% of the survivors). Reoperation was performed in 42 cases. Forty patients required revision of the inter-atrial baffle for pulmonary and/or caval venous obstruction and 10 of them subsequently died. Post-operative venous obstructions were observed more frequently in patients with dumb-bell shaped dacron patch, which has been since 6 years abandoned. Since the introduction of Brom's trouser shape pericardial patch, venous obstructions are extremely rare. Both patients who underwent reoperation respectively for severe tricuspid valve incompetence and for occlusion of the left pulmonary artery, died early after reoperation. In our Unit, the actual management program for patients with "simple" TGA is the following. We keep to a minimum the degree of invasive investigations, 2 D ECHO diagnoses TGA with great accuracy. At the initial cardiac catheterization, a balloon atrial septostomy (BAS) is performed. A good inter-atrial mixing is usually obtained with balloons sized more than 2.5 ml. Angiocardiography is undertaken only when associated lesions, such as patent ductus arteriosus or aortic coarctation are suspected. If the child improves, complete investigation is performed at 3-4 months of age and the inter-atrial redirection of the venous inflow is scheduled for the age of 8-12 months. If the child fails to improve after BAS or deteriorates during the waiting period, restudy is performed immediately to ensure that additional lesions are not present and that the inter-atrial shunt is adequate. Rather than a surgical atrial septectomy, in this group of cases we prefer an early intracardial total repair, irrespective of age and weight.

Adolescent↗
PubMed1979

Angiocardiographic appearances of atrioventricular defects with particular reference to distinction of ostium primum atrial septal defect from common atrioventricular orifice.

Preoperative distinction between common atrioventricular orifice and ostium primum atrial septal defect may be difficult. To improve diagnostic accuracy, the right and left ventricle angiocardiograms were reviewed 'blind' in 92 patients with atrioventricular defects. The true diagnosis was known from necropsy or surgery in 60. Angiocardiograms had been obtained in various projections with or without craniocaudal tilt. Those features thought to distinguish between common orifice and ostium primum were coded, together with the ventricular systolic pressures. Computerised disciminant function analysis identified the following distinguishing features: (1) right ventricular systolic pressure; (2) immediate right ventricular outflow tract opacification from the left ventricle; (3) identification of the anterior attachment of the mitral component; (4) recognition of a single straddling atrioventricular orifice; (5) passage of contrast medium above or below the anterior or posterior bridging leaflets. Feature (3) indicates that in contrast to classic teaching the direct septal attachment of the mitral component does not contribute to the 'gooseneck' in complete atrioventricular defects. The significance of (4) and (5) is that they may be identified from right as well as left ventriculography, and are more likely to be identified in oblique than standard projections. Computerisation produced a correct diagnosis in 92 per cent of known cases, and determined precise probabilities of diagnosis in the remainder.

Angiocardiography↗
PubMed1976

Pulmonary artery banding for truncus arteriosus in the first year of life.

Results of pulmonary artery banding (PAB) for truncus arteriosus (TA) in infancy are reviewed in 15 children between 1957 and 1974. There were ten hospital and one late deaths (73%). A policy of early correction of severely symptomatic infants with TA was adopted in 1974. Since October, 1974, four infants with TA and one with hemitruncus had a complete correction. Three of these are surviving 22, 17, and 9 months after the operation. Their weight at operation was 4.7, 6.0, and 3.5 kg.

Autopsy↗
PubMed1974

Management of truncal valvular regurgitation.

The presence of significant truncal valvular regurgitation presents a technically difficult and life-threatening challenge during operations for correction of the truncus arteriosus anomaly. The problem was encountered in 19 of 71 patients (26%) who underwent such operations. A simple technique for managing this problem, namely, temporary cusp approximation, has evolved and has proved successful in all 11 patients in which it was used. The indications for replacement of the regurgitant truncal valve have not yet been defined. The suggestion is made that in all but the most severe instances of truncal valvular regurgitation, persistence of the regurgitation postoperatively may currently be preferable to replacement of the valve.

Adolescent↗