Biomedical subjects
D Bonnet
Publications and source records attributed to D Bonnet.
[Intravascular rupture of a central venous catheter in a premature infant: retrieval by a nonsurgical technique].
UNLABELLED: Central venous access is a frequent procedure in pediatric intensive care and neonatology. Catheter fracture with migration of the distal portion into the vessels is rare but may have side effects such as thrombosis. CASE REPORT: We report the case of a premature infant who had at three weeks of age a retained central venous catheter fragment in the pulmonary artery. The fragment was successfully retrieved by a percutaneous endovascular technique. No complication was observed during the procedure and afterward. CONCLUSION: This technique has avoided either delicate surgery or thrombotic risk due to a persistent intravascular foreign body. The authors prompted this interventional procedure within 36 hours after catheter migration in a center experienced in neonatal interventional catheterization.
Influence of atrial septal defect anatomy in patient selection and assessment of closure with the Cardioseal device; a three-dimensional transoesophageal echocardiographic reconstruction.
BACKGROUND: The maximal diameter of the defect and the dimensions of the septal rims are essential parameters for the selection of optimal cases for device closure. Neither two-dimensional echocardiography nor balloon catheter sizing provide optimal data. Unique three-dimensional echocardiography might help to improve patient selection and assessment of results. Our aim was to optimize transcatheter closure of secundum type atrial septal defects using three-dimensional echocardiography. METHODS: Sixteen patients enrolled in a protocol for atrial septal defect transcatheter closure with the Cardioseal device underwent transoesophageal two- and three-dimensional echocardiography. Maximal diameter and tissue rim of the atrial septal defect were measured and compared by both methods. In the 12 patients selected for closure, the balloon stretched diameter was compared to three-dimensional echocardiography measurements. Device placement was assessed by two- and three-dimensional echocardiography. RESULTS: The shape of the atrial septal defect appeared variable on three-dimensional views: round in nine patients but complex (oval, raquet-shaped, multiple) in seven patients. The surface area of the atrial septal defect varied by 68+/-15% during the cardiac cycle. The correlation between atrial septal defect maximal diameters measured by two-dimensional transoesophageal echocardiography and three-dimensional echocardiography was better in round defects (y=1 x +1.6, r=0.99) than in complex defects (y=0.7 x -0.5, r=0.88). The antero-superior rim could only be properly assessed by three-dimensional echocardiography. In 12 patients the correlation between stretched diameter and three-dimensional echocardiography maximal diameter was poor (y=0.3 x +13, r=0.41). After placement of the device, three-dimensional echocardiography enabled the mechanism of residual shunting to be understood in three patients. CONCLUSIONS: Dynamic three-dimensional echocardiography enhances the understanding of the anatomy and physiology of atrial septal defect and should be an important process in future initiatives for device closures.
Characteristics and results of epicardial pacing in neonates and infants.
The results of epicardial pacing in infants with isolated congenital complete atrioventricular block (CAVB) are reported. Thirty-four patients, aged 1 day to 20 months (22 patients < 1 month), were paced between 1988 and 1998. Thirty had bradycardia < 50 beats/min with symptoms in 12 patients, and 4 patients were paced because of associated ventricular ectopy or prolonged QT interval. In thirty cases, the electrodes were implanted through a left thoracotomy and connected to an abdominal generator; in four, the subxyphoid approach was preferred. Twenty-two children had dual chamber units. There was no operative death, but three patients died later of cardiomyopathy. Seven infants were reoperated for electrode displacement, infection, exit block, and pacemaker sensitivity. Chronic ventricular thresholds ranged from 0.3 to 2 V except in one case (4 V) and proper atrial sensing was lost in two cases. All children are doing well and the generator has lasted at least 5 years in 16 cases. In conclusion, epicardial pacing in infants with CAVB can be done with satisfactory results. There was no mortality in relation with pacing and thresholds have improved with the use of steroid-eluting electrodes. The deep location of the generator prevents cutaneous erosion and allows implantation of large units with a longer life duration.
Mechanical properties of the common carotid artery in Williams syndrome.
OBJECTIVE: To determine whether arterial wall hypertrophy in elastic arteries was associated with alteration in their mechanical properties in young patients with Williams syndrome. METHODS: Arterial pressure and intima-media thickness, cross sectional compliance, distensibility, circumferential wall stress, and incremental elastic modulus of the common carotid artery were measured non-invasively in 21 Williams patients (mean (SD) age 8.5 (4) years) and 21 children of similar age. RESULTS: Systolic and diastolic blood pressures were higher in Williams patients (125/66 v 113/60 mm Hg, p < 0.05). The mean (SD) intima-media thickness was increased in Williams patients, at 0.6 (0.07) v 0.5 (0.03) mm (p < 0. 001). Normotensive Williams patients had a lower circumferential wall stress (2.1 (0.5) v 3.0 (0.7) mm Hg, p < 0.01), a higher distensibility (1.1 (0.3) v 0.8 (0.3) mm Hg(-1).10(-2), p < 0.01), similar cross sectional compliance (0.14 (0.04) v 0.15 (0.05) mm(2). mm Hg(-1), p > 0.05), and lower incremental elastic modulus (7.4 (2. 0) v 14.0 (5.0) mm Hg.10(2); p < 0.001). CONCLUSIONS: The compliance of the large elastic arteries is not modified in Williams syndrome, even though increased intima-media thickness and lower arterial stiffness are consistent features. Therefore systemic hypertension cannot be attributed to impaired compliance of the arterial tree in this condition.
The mutation spectrum in Holt-Oram syndrome.
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Arterial mechanical changes in children with familial hypercholesterolemia.
Atherosclerosis is preceded by a phase of changes in the arterial wall that could have functional consequences even before the appearance of atheromatous changes. We hypothesized that early alterations of the mechanical properties of the arterial wall could precede clinical and echographic modifications. We used an automatic, computerized, ultrasonic procedure to evaluate geometric and mechanical characteristics of the common carotid artery (CCA) in normotensive children with primary familial class IIA hypercholesterolemia (FH; n=30; mean+/-SD age, 11+/-2 years old; mean+/-SD systolic/diastolic blood pressure, 109+/-9/55+/-7 mm Hg). These subjects were compared with age-matched, nonobese control subjects (n=27; 11+/-3 years old; 112+/-10/55+/-7 mm Hg). Noninvasive ultrasonic measurements were performed by the same investigator to measure the CCA luminal systolic and diastolic diameters and intima-media thickness (IMT). The cross-sectional compliance, cross-sectional distensibility, and the incremental elastic modulus of the CCA wall were then calculated. Finally, we assessed the degree of reactive hyperemia in the brachial artery produced after distal cuff occlusion and release. The changes in brachial arterial diameter in response to reactive hyperemia (endothelium-dependent dilation) and to glyceryltrinitrate (endothelium-independent dilation) were then measured. In patients with FH, we observed a significant reduction of systodiastolic variations in diameter (by 20%, P:<0.001) without a significant difference in IMT. Cross-sectional compliance and cross-sectional distensibility were significantly reduced in FH subjects (by 15%, P:<0.05 and 19%, P:<0.01, respectively). In parallel, the incremental elastic modulus was significantly increased (by 27%, P:<0.01) in children with FH. No correlation was evident between the carotid incremental modulus and either IMT or plasma low density lipoprotein cholesterol level. There was no difference in diameter of the brachial artery at rest in control and FH subjects (3.0+/-0.5 versus 3.0+/-0.4 mm). The reactive hyperemia and glyceryltrinitrate dilation were also similar in the 2 groups. However, the flow-mediated dilation of the brachial artery was smaller in the FH subjects (4.2+/-2.9%) than in controls (9.0+/-3.1%, P:<0.001). In FH, endothelium-dependent dilation was negatively correlated with the plasma low density lipoprotein cholesterol level (P:<0.04). These results indicate that increased stiffness of the CCA wall in children with FH is independent of blood pressure and could be related to endothelial dysfunction. Thus, alterations in CCA wall mechanics could be early and easily measurable markers of atheromatous changes in the arterial wall.
[Percutaneous closure of patent ductus arteriosus with the Amplatzer duct occluder].
BACKGROUND AND METHODS: Percutaneous closure of a moderate-to-large sized patent ductus arteriosus using multiple coils or a Rashkind double-umbrella may be technically demanding and raises a significant rate of embolization and residual shunting. This is why we tried a new self-expandable device called Amplatzer Duct Occluder to close transvenously large ductuses in eighteen patients at a median age of 2.8 years (range: 0.7 to 34). They had a patent ductus arteriosus with a minimal diameter > 3 mm (mean: 5 +/- 2 mm). The device had a mean diameter of 9 +/- 2 mm and was delivered through a 6F venous sheath. Aortography was done 5 to 10 minutes after the release and follow-up evaluation was performed with color Doppler echocardiography within 24 h, 1 and 3 to 6 months after the procedure. RESULTS: Placement was successful in all but the first patient (95%). Complete closure was achieved immediately in 4/17 patients (24%) and in 13/17 (76%) 24 h later. Two patients were lost for follow-up. Complete closure was confirmed in 14 of the 15 (93%) reviewed patients at 1 and 3 months. In all patients with a ductal diameter < or = 7.5 mm the closure was complete at 1 month. Embolization occurred in one patient with a 9.7 mm duct and surgery was undertaken. A mild and transient hematuria was observed in one patient. No pulmonary artery stenosis nor aortic obstruction were observed on follow-up. CONCLUSION: The Amplatzer Duct Occluder device offers a safe and effective option to treat patients with a ductus arteriosus which minimal diameter is up to 7.5 mm.
[Three-dimensional reconstruction by transesophageal echocardiography of Amplatzer and CardioSEAL prosthetic devices after percutaneous closure and atrial septal defects].
OBJECTIVE: The Amplatzer and cardioSEAL devices are currently used for percutaneous closure of atrial septal defects. The in vivo morphology of these devices is unknown and this is why we sought to describe their geometric profile by three-dimensional echocardiography. METHODS: Thirteen patients, aged 6 to 18, underwent transcatheter closure of a secundum type atrial septal defect with either the CardioSEAL (n = 8) or the Amplatzer (n = 5) device. Three-dimensional reconstructions of the defect were obtained from transoesophageal bidimensional echocardiographic views. RESULTS: In the Amplatzer group, the stretched diameter of the defect was larger than in the CardioSEAL group (22 +/- 2 vs 18 +/- 1 mm, p = 0.003), but ehocardiographic surfaces were the same (3.3 +/- 1 vs 3.6 +/- 1 cm2, p = 0.3). The surface of the CardioSEAL device was measured at 4.8 +/- 2 cm2 whereas the Amplatzer's surface was 6.8 +/- 2 cm2 (p = 0.03). The Amplatzer device had a volume of 9 +/- 1 cm3 while the CardioSeal's volume was 3.1 +/- 1 cm3 (p < 0.0001). CONCLUSIONS: The CardioSEAL device occupies a small volume but it covers less of the septal defect and this may result in a higher incidence of residual shunting. The Amplatzer device almost always occludes the septum, but it tends to bulge into the atria and may cause mechanical complications.
[Cardiac pacing in children with breath-holding spells].
Breath-holding spells are common and usually benign. However, the authors chose to implant a pacemaker in children presenting with severe symptoms. Over the last 15 years, 11 children with severe breath-holding spells were paced. All had reflex spells with loss of consciousness, spontaneously or after minor trauma, and 6 had seizures. All had a normal ECG with marked bradycardic responses to ocular pressure. The 24 hour ECG showed pauses (12-25 s) in 4 patients, sudden bradycardia (< 30/min) in 3 patients, and sinus arrhythmia in the remaining 4 patients. Medical treatment has been unsuccessful. Pacemaker implantation was decided because of the severity and/or the frequency of the episodes in 10 children, and because of intolerable familial anxiety in the other one. Age at implantation ranged from 14 months to 5.5 years (mean: 16.5 +/- 20 months). The device was implanted by an epicardial (7) or from an endocardial (4) approach. All had a ventricular demand device, except for one who was paced from the atrium. The results were spectacular, with disappearance of spells and restoration of normal activities. Holter monitoring showed normal function of the pacemakers. Recurrences were observed in 3 patients, either due to loss of capture (2 cases) or to the need for explantation because of cutaneous erosion. Follow-up ranged from 10 months to 14 years (mean: 7.9 +/- 4.2 years); 2 patients were lost to follow-up; 4 patients totally recovered and only 5 are still vagotonic. Two pacemakers have been changed at 13 and 15 years respectively. The authors conclude that although psycho-social factors play a part in breath-holding spells, pacemaker implantation is very effective in suppressing symptoms in severely affected children.
[Therapy and prognosis of infectious complete atrioventricular block in children].
From 1983 to 1997, we have studied ten children with complete atrioventricular block likely due to myocarditis in order to assess its prognosis and to define a therapeutic strategy. Their age ranged from 6 days to 16 years (median: 4.1 years). All were admitted for sudden complete block, with symptoms in seven: syncope or fainting, seizures, collapse. Three had an asymptomatic bradycardia which was detected on routine auscultation in children with fever or already hospitalized; fever was present in 5. The disease was related to infection on biological data in 4 cases (1 listeriosis and 3 seroconversions for Epstein Barr or cytomegalic or Coxsackie B viruses), on a myocardial biposy in 1 case and on scintigraphic data in 1 case. In the remaining 4, indirect arguments were considered such as infectious context, normal recent ECG, favourable outcome. Five children were given intravenous isoprenalin with ventricular tachycardia in 3. Five were treated with steroids and 3 with specific antiviral agents. Seven patients were paced temporarily. One child died, 6 recovered totally and 3 have a permanent block with a definitive pacemaker implanted in 2. In conclusion, sudden acquired complete atrioventricular blocks are often ill-tolerated in children and have to be treated with transient pacing. Recovery occurs as a rule but some of these blocks may be definitive. Infective myocarditis is likely to be the cause of the disease even if the pathogen agent cannot always be identified.
[Prenatal diagnosis of conotruncal heart diseases. Results in 337 cases].
Prenatal diagnosis of conotroncal disease has developed by examination of the great arteries during morphological foetal ultrasonic scanning in the second term of pregnancy. This study reports the results of a series of 337 of these malformations diagnosed in the foetus over five and a half years. Their incidence with respect to all foetal cardiac malformations is 16.2%. Tetralogy of Fallot and pulmonary atresia with ventricular septal defect make up 56% of these cases, vascular malposition 16%, coarctation with or without interruption of the aortic arch 14%, truncus arteriosus 9% and agenesis of the pulmonary valves 5%. A karyotypic anomaly was found in 28 cases (8.2%) and, in the foetus with a normal standard karyotype, deletion of chromosome 22q11 was identified in 54 out of 237 cases. There was an associated polymalformative syndrome in 29 cases (8.3%). The training of obstetricians has increased the number of antenatal diagnoses of conotroncal abnormalities. Prenatal counselling should be given by a pluridisciplinary team because the association of these malformations with chromosomal abnormalities or with syndromes difficult to diagnose is common.
[Pseudo-inherited form of left heart obstructive defects revealing maternal phenylketonuria].
If an adequate diet is not given to mothers with phenylketonuria, their offsprings often exhibit intra-uterine growth retardation with associated microcephaly and various malformations. Here, we report two families in whom we observed recurrent left heart malformations associated with microcephaly masquerading as a mendelian condition and revealing a maternal phenylketonuria. These observations suggest that when confronted to recurrent heart malformations with extra-cardiac defects that are not due either to an inherited chromosomal anomaly or to a well characterized mendelian disease, a maternal teratogen should be identified and more particularly maternal hyperphenylalaninemia if an intra-uterine growth retardation or a microcephaly is part of the syndrome.
[Solitary cerebellous tumor discovered at extension work-up for primary lung cancer].
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[Genetics. Genetic tests in children. An immediate reflexion is needed].
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[Cardiovascular impact of end-stage renal insufficiency in children undergoing hemodialysis].
Cardiac hypertrophy and arterial dysfunction have been described in end-stage renal disease (ESDR) in adults. The incremental elastic modulus (Einc), is a marker of vascular wall material stiffness and an independant predictor of cardiovascular mortality in adults with ESRD on hemodialysis. The relationship between arterial changes and the heart is unknown in the children with ESRD in the same conditions. Using a high-resolution vascular ultrasound and a computerized system of measurement (Iotec), we assessed noninvasively 10 ESRD patients (mean +/- SD, age, 11.5 +/- 4 years; blood pressure [BP], 120 +/- 10/63 +/- 4 mmHg) and 10 age-, sex-, and BP-matched controls (mean +/- SD, age, 11 +/- 4 years; BP, 114 +/- 8/58 +/- 8 mmHg). The systolic and diastolic diameter of the common carotid artery (CCA), the thickness of the wall (intima-media thickness, IMT), the cross sectional compliance (CSC), the cross sectional distensibility (CSD) and the (Einc) were determined. CSC and CSD were evaluated at the same level of pressure. The CCA pressure waveform was obtained by applanation tonometry to assess the reflected wave by the augmentation index (AI). Further the left ventricular mass index was assessed. The flow mediated dilation (FMD) (endothelium-dependent function) and the vasodilation induced by glyceryl-trinitrate (GTNMD) (GTN, an endothelium-independent dilator) were evaluated at the brachial artery site. Compared to control subjects, ESRD patients have mechanical artery dysfunction with lower CSC and CSD (0.11 +/- 0.04 vs 0.18 +/- 0.05 mm2.mmHg-1; p < 0.01; 0.43 +/- 0.10 vs 0.82 +/- 0.20 mmHg-1.10(-2); p < 0.001) and higher Einc (2.60 +/- 1.00 vs 1.40 +/- 0.30 mmHg.10(3); p < 0.001). Furthermore an earlier return of the reflected pulse wave (AI -0.24 +/- 0.08 vs -0.58 +/- 0.06; p < 0.005) is correlated to LV mass index (r = 0.55, P < 0.01) that is significantly increased (134 +/- 63 vs 69 +/- 25 g/m2; p < 0.005). These patients have an impaired FMD (4 +/- 2 vs 7 +/- 1%; p = 0.02) with a normal GTNMD. This study shows that early arterial dysfunction can occur in children with ESRD.
[An uncommon cause of persistent fever in France].
Miliary tuberculosis is rare and requires rapid diagnosis. Outcome is fatal in 25% of the cases. Since radiography and laboratory tests contribute little to early diagnosis, clinical findings are primordial. Antituberculosis antibiotic therapy is frequently started before microbiological confirmation of the diagnosis.
Arrhythmias and conduction defects as presenting symptoms of fatty acid oxidation disorders in children.
BACKGROUND: The clinical manifestations of inherited disorders of fatty acid oxidation vary according to the enzymatic defect. They may present as isolated cardiomyopathy, sudden death, progressive skeletal myopathy, or hepatic failure. Arrhythmia is an unusual presenting symptom of fatty acid oxidation deficiencies. METHODS AND RESULTS: Over a period of 25 years, 107 patients were diagnosed with an inherited fatty acid oxidation disorder. Arrhythmia was the predominant presenting symptom in 24 cases. These 24 cases included 15 ventricular tachycardias, 4 atrial tachycardias, 4 sinus node dysfunctions with episodes of atrial tachycardia, 6 atrioventricular blocks, and 4 left bundle-branch blocks in newborn infants. Conduction disorders and atrial tachycardias were observed in patients with defects of long-chain fatty acid transport across the inner mitochondrial membrane (carnitine palmitoyl transferase type II deficiency and carnitine acylcarnitine translocase deficiency) and in patients with trifunctional protein deficiency. Ventricular tachycardias were observed in patients with any type of fatty acid oxidation deficiency. Arrhythmias were absent in patients with primary carnitine carrier, carnitine palmitoyl transferase I, and medium chain acyl coenzyme A dehydrogenase deficiencies. CONCLUSIONS: The accumulation of arrhythmogenic intermediary metabolites of fatty acids, such as long-chain acylcarnitines, may be responsible for arrhythmias. Inborn errors of fatty acid oxidation should be considered in unexplained sudden death or near-miss in infants and in infants with conduction defects or ventricular tachycardia. Diagnosis can be easily ascertained by an acylcarnitine profile from blood spots on filter paper.