High prevalence of ventricular repolarization abnormalities in people carrying TGFßR2 mutations.

Mutations in the TGFßR2 gene have been associated with a life threatening risk of aortic dissection but no arrhythmic death has been previously reported. Two young females carrying a TGFßR2 mutation, initially diagnosed as Marfan syndrome or Loeys Dietz syndrome, presented sudden death with autopsy ruling out dissection. The ECGs of the 2 Sudden Cardiac Deaths revealed profound ventricular repolarization abnormalities with a sinusoidal T-U morphology associated with normal left ventricular ejection fraction. These data strongly suggest sudden cardiac arrhythmic deaths and prompted us to systematically study the repolarization pattern in the patients with TGFßR2 mutations. ECG findings from 58 mutation carriers patients (TGFßR2 group) were compared with those of 46 non-affected first degree relatives (control group). TGFßR2 mutation was associated with ventricular repolarization abnormalities in 47% of patients (p < 0.001 vs. controls), including a 19.6 ms (95%CI 8.7; 30.5) QTc interval prolongation compared to the non-affected first degree relatives (p < 0.001), higher prevalence of abnormal U waves (16% vs. 2%), and sinusoidal T-U morphology (10% vs. 0%). TGFßR2 mutations can be associated with abnormal ventricular repolarization pattern, longer QT interval than non-carrier relatives and an increased risk for sudden death.

De novo malignancy after solid organ transplantation in children.

The aim of this study was to assess the prevalence of de novo malignancy after solid organ transplantation in childhood. A retrospective questionnaire-based survey was sent to 9 referral centers for pediatric organ transplantation in France. Among 1326 children who underwent solid organ transplantation since 1996, 80 (6%) presented with de novo malignancy posttransplantation during childhood: posttransplant lymphoproliferative disease was the most common (5% of pediatric recipients) comprising 80% of all tumors, with a disproportionately high prevalence among combined liver and small bowel recipients (18%). Various solid tumors were observed mainly among kidney recipients. No skin cancer was reported.

[A case report of Williams and Beuren syndrome with associated aggravation of in situ distal pulmonary vascular obstruction due to thrombotic disease]. / Une observation de syndrome de Williams et Beuren avec aggravation de l'obstruction vasculaire pulmonaire distale par maladie thrombotique in situ associée.

We report a case of Williams and Beuren syndrome in which the obstruction of the pulmonary vascular bed, linked with peripheral stenoses of the pulmonary arteries, associated here with an interventricular communication, was aggravated due to the coexistence of in situ thrombotic disease, leading to a progressive hypoxaemia, requiring long-term anticoagulant treatment, and compromising the long-term prognosis. This case report puts into question the so-called favourable prognosis of pulmonary arterial branch stenoses in this malformation syndrome.

Minimum effective dose of midazolam for sedation of mechanically ventilated neonates.

OBJECTIVE: To determine the minimal effective dose (MED) of intravenous midazolam, required for appropriate sedation in 95% of patients, 1 h after drug administration. METHODS: A double-blind dose-finding study using the continual reassessment method, a Bayesian sequential design. Twenty-three newborn infants hospitalized in intensive care unit participated. Inclusion criteria were: (i) post-natal age <28 days, (ii) gestational age >33 weeks, (iii) intubation and ventilatory support required for respiratory distress syndrome, (iv) need for sedation (i.e. one of the six following criteria: agitation or grimacing or crying facial expression before tracheal suctioning, agitation or grimacing or crying facial expression during tracheal suctioning). Each neonate was allocated to a loading dose, ranging from 75 to 200 microg/kg, and a maintenance dose ranging from 37.5 to 100 microg/kg/h. RESULTS: The primary endpoint was the level of sedation 1 h after the onset of infusion. The sedation procedure was classified as a success if all the following clinical criteria were met: no agitation, no grimacing and no crying facial expression before as well as during tracheal suctioning. Based on the 23 patients, the final estimated probability of success was 76.9% (95% credibility interval: 56.6-91.4%) for the 200 microg/kg loading dose. no significant adverse effect was observed. CONCLUSIONS: Continual reassessment is a new approach, suitable for dose-finding study in neonates. this method overcomes some of the ethical, statistical and practical problems associated with this population. Using this method, the MED was estimated to be the 200 mug/kg loading dose of midazolam.

[Cardiac retransplantation in childhood. Questions and answers]. / Retransplantation cardiaque en pédiatrie. Interrogations et réponses.

Cardiac transplantation in childhood remains a long-term palliative procedure and it is probable that an increasing number of patients undergoing this procedure in childhood will require a new transplant one day. Coronary artery disease of the transplanted heart is the main indication. The results (in terms of survival and morbidity) in the literature and in the authors' experience are encouraging and justify the indication for retransplantation in cases of severe coronary disease of the transplanted heart. The indication is not as clear-cut in transplantation performed early or as an emergency for primary graft dysfunction, which carries a high mortality. Renal failure and allo-immunisation are not contra-indications to this procedure. Occasionally, procedures of coronary revascularisation provide time to wait for a new transplant. In the absence of more effective preventive or curative treatment of coronary disease of the transplant, the good results of retransplantation justify the procedure for this indication and reinscription on the waiting list for cardiac transplantation.

[Followup of adults with a Fontan-type cavopulmonary derivation]. / Surveillance d'un adulte ayant eu une dérivation de type Fontan ou cavopulmonaire.

The Fontan procedure is a technique used in single ventricle syndromes and initiates a circulation which bypasses the right ventricle. It was described by Fontan in 1971. Many variations of this operation have been described and classified under the term of total cavopulmonary derivation. These operations result on long-term functional benefit. However, the 15 year survival rate is only 55 to 80%. This procedure (often carried out in childhood) is considered to be palliative rather than curative. The mortality is due to long-term complications, the frequency of which increases with the length of follow-up of the patient. The causes are: the Fontan circulation itself (arrhythmias, thrombosis, inferior caval stasis (hepatic, exsudative enteropathy), recurrence of cyanosis): the underlying cardiac disease (ventricular failure, atrioventricular valvular regurgitation); other complications (endocarditis and extracardiac, in particular orthopedic problems). Any of these complications may be an indication for cardiac transplantation, a high risk procedure because of previous multiple surgical interventions.

[Percutaneous closure of an interatrial communication via the internal jugular route using an Amplatzer prosthesis]. / Fermeture percutanée d'une communication interauriculaire par voie jugulaire interne par une prothèse d'Amplatzer.

Closure of interatrial communications by interventional catheterisation is recommended and effective. The usual approach is via the femoral vein. However, difficulty in positioning the probe and the guide in a stable fashion across the septal defect occurred during closure of the interatrial communication by the percutaneous route in a 71 year old female with severe scoliosis. This deformity most certainly contributed to the failure of the femoral approach. The decision for closure by the internal jugular route was taken and allowed closure of the interatrial communication to be achieved. The internal jugular route can be an alternative for closure of interatrial communications with difficult access.

[Marfan syndrome in the newborn and infants less than 4 months: a series of 9 patients]. / Syndrome de Marfan chez le nouveau-né et le nourrisson de moins de 4 mois: une série de 9 patients.

We report a series of 9 children with neonatal Marfan syndrome. The diagnosis was made on a striking facial dysmorphia associated with arachnodactyly type skeletal anomalies. They all had cardiovascular anomalies: aortic dilatation 9 times, and mitral and/or tricuspid valve prolapse 8 times. Three children underwent ascending aorta replacement with the Yacoub technique. There was one operative death in a young infant and the two survivors required further surgery for gross mitral insufficiency and an aneurysm of the horizontal aorta. Three children died before the age of 1 year from cardiac insufficiency linked to massive leaks of all the valves. The three youngest children in the series did not undergo any procedure and were followed up for a slowly growing dilatation of the initial aorta. The prognosis of neonatal Marfan syndrome is weighted with a heavy mortality. The timing of surgical intervention in case of excessive dilatation of the aortic root is difficult to determine. It depends not only on the aortic diameter but also on the aortic valve function and the existence of other mitral or tricuspid lesions. Surgical treatment for lesions of the initial aorta and the atrioventricular valves improves the short-term prognosis but the risk of re-intervention is higher.

[Percutaneous closure of a paravalvular mitral regurgitation with Amplatzer and coil prostheses]. / Fermeture percutanée d'une fuite paravalvulaire mitrale avec prothèses d'Amplatzer et coil.

The authors report a case of percutaneous closure of paravalvular mitral regurgitation in a 9 year old child. This patient had complete atrioventricular canal with levo-isomerism completely repaired with replacement of the left atrioventricular valve by a mechanical prosthesis. One year after an episode of infectious endocarditis, the patient was readmitted because of jaundice due to haemolysis attributed to paravalvular mitral regurgitation. Transoesophageal echocardiography demonstrated a crescent-shaped dehiscence of the prosthesis opposite the left atrial appendage associated with a small paraseptal regurgitation. First of all, a 6 mm Amplatzer Septal Occluder and a 5 x 5 coil were introduced by retrograde catheterisation to treat the regurgitation due to the valve dehiscence. This procedure was completed 3 months later by the implantation of a second 8 mm Amplatzer prosthesis for persistent haemolysis. Closure of the paraseptal regurgitation resulted in a reduction of the patient's transfusional requirements.

[Interest in myocardial scintigraphy following the arterial switch procedure for transposition of the great vessels]. / Intérêt de la tomoscintigraphie myocardique au décours de la correction artérielle des transpositions des gros vaisseaux.

Coronary artery obstruction is the main late complication of the so-called arterial switch operation designed to repair transpositions of the great arteries in newborn infants by switching the great vessels and transferring the coronary ostia onto the posterior vessel. Our aim was to study the links between myocardial perfusion and coronary artery anatomy after the arterial switch operation. Forty-five patients (5.863 years) underwent a 201Tl myocardial SPECT and a selective coronary artery angiography. The latter was normal in 20 children: 13 had also a normal myocardial scan but 7 had myocardial perfusion defects including 2 with angina who had a very low coronary reserve at positron emission tomography. Twenty-five patients had severe coronary artery lesions: 5 with a normal myocardial scan and 20 with perfusion defects. Twelve out of these 20 underwent surgical revascularization and the SPECT images went back to normal in all within 6 months after surgery. Specificity and sensitivity of myocardial SPECT in detecting coronary artery lesions were 78% and 69% whereas positive and negative predictive values were 74 and 73%. We conclude that myocardial SPECT imaging is not the right way to detect late post arterial switch coronary artery lesions. It is helpful in decision making as to submit these children to surgical revascularization and in assessing its postoperative effectiveness.

[Intravascular rupture of a central venous catheter in a premature infant: retrieval by a nonsurgical technique]. / Rupture intravasculaire de cathéter épicutanéocave chez le prématuré: place du cathétérisme interventionnel.

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.