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Biomedical subjects

F Marçon

Publications and source records attributed to F Marçon.

At least 37 records · Page 2Linked to original sources
PubMed2000

[Junctional tachycardia in adolescents: nodal reentry is the most frequent cause].

UNLABELLED: Ventricular preexcitation syndromes are classically more common in the pediatric age group than in adults, and a latent Kent bundle may explain most cases of paroxysmal junctional tachycardia (PJT). These data stem from the results of intracardiac electrophysiologic testing, which is performed only in those patients at the most severe end of the symptom spectrum. The recent introduction of transesophageal testing has expanded the indications of electrophysiologic testing for PJT. This technique was used to determine the mechanism of PJT in 23 adolescents aged 11 to 9 years (mean age, 16 +/- 3 years) with paroxysmal palpitations, accompanied in seven cases with dizziness or syncope. Only four patients had documented PJT. The basal ECG was normal, and exercise testing showed no evidence of preexcitation. Pacing at increasing rates and programmed stimulation with one then two extra-stimuli was used and repeated, if needed, under infusion of 20 to 30 micrograms of isoproterenol. RESULTS: PJT was induced in 21 patients (91%), under basal conditions in 13 and under isoproterenol in eight. Neither of the two patients with a negative test had documented tachycardia. Based on classic criteria (position of A relative to V1, effect of a bundle branch block, and shape of A in D1 and V1), the mechanism of the PJT was shown to be nodal reentry in 17 cases (81%) and reentry into a latent left-sided Kent's bundle in four cases. Atrial fibrillation was also induced in two of the patients with nodal reentry. In six of the patients with dizziness or syncope associated with palpitations, these symptoms were due to nodal reentry. CONCLUSION: Nodal reentry is very common in adolescents and can explain symptoms ascribed to "spasmophilia", as well as some cases of malaise or syncope.

Adolescent↗
PubMed1999

Induction of sustained ventricular tachycardia after surgical repair of tetralogy of Fallot.

Between 1980 and 1996, 89 unselected consecutive patients with repaired tetralogy of Fallot (TOF) underwent examination, including a prospective right ventricular programmed stimulation with the same protocol (S1 S2, S3, S4). Age at surgery was 4.2 +/- 3.5 years and age at electrophysiologic study was 10.9 +/- 6.5 years. Follow-up since surgery was 14.4 +/- 4.8 years and patient follow-up after programmed stimulation was 7.8 +/- 4.2 years. The aim of this study was to evaluate the main predictors of the inducibility of a sustained monomorphic ventricular tachycardia (VT) and its significance to identify a group of patients at risk of sudden death: 21 (group A) had and 68 (group B) had no induced sustained VT. The induction of VT was related to older age at programmed stimulation, prolonged QRS duration, presence of complex ventricular arrhythmia, symptoms, right ventricular overload, and increased right ventricular systolic pressure. Predictors of induced VT selected by multivariate analysis were age at electrophysiologic study (p <0.0001), previous palliative shunts (p <0.001), right ventricular systolic pressure (p <0.007), and symptoms (p <0.005). Among group A patients, 4 had previous sustained VT before stimulation, and 1 had sustained VT only during follow-up after stimulation. No patients of group B had clinical sustained VT. Late mortality was low but similar between both groups. A negative electrophysiologic study may be helpful for the management of patients after surgical repair of TOF, but because the arrhythmic event rate is low, the findings of even a positive electrophysiologic study should be interpreted with caution.

Adolescent↗
PubMed1999

Surgical management of progressive pulmonary venous obstruction after repair of total anomalous pulmonary venous connection.

BACKGROUND: The occurrence of a progressive pulmonary venous obstruction after the repair of the total anomalous pulmonary venous connection is a severe complication. OBJECTIVES: The objectives of this study were to retrospectively review the patients with this condition and to report our experience with a new surgical technique with a sutureless in situ pericardium repair. METHODS: Of 178 patients who underwent correction of total anomalous pulmonary venous connection, 16 patients (9%) experienced the development of a progressive pulmonary venous obstruction in a median interval of 4 months (5 weeks-12 years). Three patients had isolated anastomotic stenosis, 4 patients had isolated pulmonary venous ostial stenosis, and 9 patients had both. Pulmonary venous obstruction was bilateral in 7 patients. The surgical procedures used at reoperation included 8 patch enlargements, 5 ostial endarterectomies, 1 intraoperative stenting, and 7 sutureless in situ pericardium repairs. RESULTS: There were 4 deaths after reoperation (4 of 15 patients; 27%). The only significant mortality risk factor was the bilateral location of the pulmonary venous obstruction (P =.045). In patients with isolated anastomotic stenosis or with only 1 pulmonary venous ostial stenosis (n = 5), there was no death, except the patient presenting with a single ventricle. In patients with 2 or more pulmonary venous ostial stenoses (n = 10), there were 3 deaths; 5 of the 7 survivors were successfully treated with the in situ pericardial technique, with normalized pulmonary artery pressure at a mean follow-up of 26 months. CONCLUSION: Progressive pulmonary venous stenosis after repair of total anomalous pulmonary venous connection remains a severe complication when bilateral. The sutureless in situ pericardial repair offers a satisfactory solution, particularly on the right side.

Female↗
PubMed1998

[5-year results of arterial correction in transposition of great vessels].

A prospective study was performed on in-hospital patients between June 1985 and July 1992 to assess the 5 year results of surgical detransposition of the great arteries. Clinical examination, electrocardiography, echocardiography, right and left heart catheterisation with selective coronary angiography, isotopic right and left ventricular ejection fractions at rest and with infusion of dobutamine and SestaMibi myocardial perfusion scintigraphy at rest and with dipyridamole, were performed during the 5th year after surgery. Twenty-six children underwent this protocol: eight others did not come for examination because they had moved from the region, one of whom had suffered regressive postoperative myocardial infarction. All patients were asymptomatic and had only minor electrocardiographic changes. Stenosis of the pulmonary tract was observed in 38.5% but only one case of stenosis at the origin of the right pulmonary artery required percutaneous angioplasty, which was successful. Pulmonary regurgitation was a common echocardiographic finding (65.4% of cases) but rarely severe (1/26: 3.9%). Aortic regurgitation was also observed commonly (53.8%), nearly always mild, grade I (13/14 cases). No significant stenosis of the aortic anastomosis was observed. The right and left ventricular ejection fractions were normal at rest except in one case and all values improved with dobutamine. Myocardial scintigraphy did not show any perfusion defect and there was no stenosis or occlusion of the coronary arteries at coronary angiography. The authors conclude that the results of arterial detransposition at 5 years are satisfactory in this series, with no cases of major obstructive lesions, major ventriculo-arterial regurgitation, ventricular dysfunction or coronary lesions. However, longer term trials with larger numbers of patients are required to determine the real incidence of coronary lesions and the long-term outcome of the pulmonary valve in the systemic position.

Cardiac Catheterization↗
PubMed1997

[Prognosis and outcome of idiopathic dilatation of the right atrium in children. A cooperative study of 15 cases].

Idiopathic dilatation is a rare abnormality corresponding to isolated aneurysmal dilatation of the right atrium, the outcome of which is not well known. Therefore a multicentric retrospective study was set up by the paediatric working group of the French Society of Cardiology recensing 7 boys and 8 girls who were diagnosed with this condition between 1971 and 1993. Ten of the children were asymptomatic and the diagnosis was suggested by the chest X-ray: one neonate had cardiac failure secondary to atrial tachycardia. The diagnosis has been facilitated by echocardiography since 1980. In this series, since 1993, four diagnoses were made antenatally. The outcome was variable : eight children are alive and well with follow-up periods ranging from 2 to 15 years (average 6 years) : four children have had cardiac arrhythmias : benign atrial extrasystoles (1 case), junctional reentrant tachycardia (1 case). The other two had more severe arrhythmias with flutter in a 7 year-old and one neonatal atrial tachycardia. The outcome was favourable with medical treatment. Three children underwent surgical atrial resection : the outcome has been good in these 3 cases with follow-up periods of 4, 13 and 18 years. This series shows that idiopathic dilatation of the right atrium is usually a well tolerated abnormality but unexpected complications may arise which can be severe such as arrhythmias, or which may be potentially threatening such as interatrial thrombosis. Management consists of either follow-up to diagnose complications which require appropriate treatment of systematic surgical correction as some authors suggest.

Adolescent↗
PubMed1997

[Familial supravalvular aortic stenosis. Investigation in a family and review of the literature].

Familial supravalvular aortic stenosis is a rare autosomal dominant condition. It may be distinguished from the Williams-Beuren syndrome by the absence of the characteristic dysmorphic appearances and of mental retardation. The case of a 9-year-old girl with a severe surgical stenosis led to the diagnosis of the same malformation in the mother and two brothers. This family adds to the 121 cases reported in the literature describing the main features of SVAS. Molecular biological advances have shown that familial SVAS and the Williams syndrome are due to mutation of the elastin gene located at 7q11-23. In the Williams syndrome the allele of this gene is completely absent and there is also probably deletion of contiguous genes, which explains involvement of cognitive function. In SVAS, the genetic lesion, mutation or microdeletion is more limited, explaining the usually isolated aortic malformation. Other studies are necessary to confirm these results.

Adult↗
PubMed1996

[French experience in the closure of atrial septal defects of the ostium secundum type with the Sideris button occluder].

From February 1992 to November 1995, four French teams used the Sideris button occluder to close 122 ostium secundum, foramen ovale or surgical fenestration atrial septal defects in 121 patients aged 2 to 79 years with body weights of 10 to 96 kg. a left-to-right shunt in 110 cases (average QP/QS = 2.09) or right-to-left shunt in 12 cases. The usual type of prosthesis was used in 115 cases, 8 centered on a guide wire, reverse type in 5 cases and the "centering-device" type in 2 patients. Nineteen implantation attempts were abandoned before releasing the prosthesis. The immediate results were: closure of the atrial septal defect in 116 patients: 59 were completely occluded, 43 had minimal residual shunts. Five patients were operated for non-buttoning or malposition of the prosthesis. In one other case, the device was removed by catheterisation. During follow-up ranging from 1 month to 3 years, 20 patients were operated for varying complications, the commonest of which was malposition of the prosthesis (17 cases) with a shunt of variable volume. In one other case, a second device was inserted. Seventy-seven patients were reviewed at 1 year, 28 a 2 years and 6 at 3 years. The residual shunts decreased with time but only completely disappeared in half the cases. Secondary fractures not requiring surgery were observed in 5 patients. Failures and complications were the result of various causes which are discussed. Successive technological improvements and the experience of the medical teams should reduce this incidence, but caution is required especially in the treatment of young children.

Adolescent↗
PubMed1996

[Effects of age on the response to Tilt test in patients with malaise or syncopes].

The diagnosis of vasovagal malaise or syncope, suspected from the clinical history, may be confirmed by the tilt test. The aim of this study was to assess the effects of age on the results of this test in 346 patients who had unexplained malaise or syncope. Thirty-one patients were 7 to 19 years of age (group I), 59 were 20 to 40 (group II), 72 were 41 to 60 (group III) and 184 were 61 to 85 years old (group IV). The patients were maintained in the dorsal decubitus position for 20 minutes and then raised to 70 degrees until a malaise was observed or for a maximum of 40 minutes. The malaise or syncope was reproduced by the tilt test in 135 cases (39%). The number of positive responses was comparable in group I, II, III and IV (45, 42, 32 and 40%, respectively). The time before the malaise occurred was also similar in the four groups (17, 19, 15 and 20 minutes, respectively). Two responses to the tilt test characterised the different age groups: the greater number of malaises occurring independently of a drop in blood pressure or change in heart rate ("psychiatric" syncope) in group II compared with groups I, III and IV (40% versus 7, 9 and 9.5%); the higher frequency of pure vasodepressive forms in group IV compared with groups I, II and III (66% versus 28.5, 32 and 39%). In conclusion, the probability of a positive tilt test does not change with age. The mechanisms of the symptoms produced is the only difference observed with age.

Adolescent↗
PubMed1995

[Interventional catheterization in infants and neonates].

Indications for interventional catheterism in new-born and very young infants have been widened through technical progress and clinical experience. Such procedures are still very difficult to perform at this age and many indications are still under debate. Currently interventional catheterism is used for curative treatment of tight pulmonary valve stenosis, the pulmonary stenosis in Fallot's tetrology, clinically threatening aortic valve stenosis in infants or new-borns. Other procedures include vessel dilatations, in particular for coarctation of the aorta, placing vascular stents, closing ductus arteriosus or vascular embolizations. The question of the respective role of surgery versus interventional catheterism remains open for many indications. As progress is made, both techniques remain valid and should be considered as complementary tools for many congenital heart diseases.

Catheterization↗
PubMed1995

[Long-term efficacy and tolerability of amiodarone in children].

The authors reviewed the files of 37 patients under 15 years of age (22 boys and 15 girls) in order to study the long-term efficacy and tolerance of amiodarone therapy. The mean age of the patients at the time of initiation of amiodarone was 6.2 +/- 4.7 years. Amiodarone was prescribed at a loading dose of 500 mg/m2 and at a maintenance dose of 250 mg/m2. This drug was prescribed in second intention in 29/37 patients and as monotherapy in 15/37 patients. The treated arrhythmias were supraventricular in 25 patients (atrial: 10; junctional: 15) and ventricular in 12 patients. Underlying cardiac disease was present in 21/37 patients (57%) and the arrhythmias were postoperative in 14/37 cases (38%). Efficacy and tolerance of amiodarone were estimated on clinical and biological data, the results of Holter monitoring, ophthalmological slit-lamp examination and thyroid function tests. The average duration of therapy was 4 +/- 3 years. The efficacy of amiodarone was judged to be good in 59% and satisfactory in 38% of cases. Secondary effects and complications included: corneal deposits: 14 cases (38%); skin pigmentation: 1 case; photosensitivity: 10 cases (27%). There was a high incidence of thyroid disorders: 7 cases (19%) with 4 cases of biological or clinical hyperthyroidism and 3 cases of clinical or biological hypothyroidism.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1995

[Repeated thrombolysis and difficulties in treatment with antivitamin K in an infant with mitral valve prosthesis].

The finding of cardiac failure in a neonate led to the diagnosis of congenital mitral regurgitation complicating dystrophic valves. After failed surgical valvuloplasty, the child underwent mitral valve replacement with a Saint-Jude medical prosthesis at the age of 4 months. The child developed four episodes of prosthetic valve thrombosis in the two years that followed. The first was treated surgically but the three others were treated by thrombolysis associating plasminogen tissue activator and urokinase. All but one of the thromboses occurred in a context of recent destabilisation of oral anticoagulant therapy despite the initiation of heparin. Repeat thrombolysis was successfully undertaken, thereby widening the indications of this type of treatment in the infant. This case also underlines the difficulties of oral anticoagulants in infants.

4-Hydroxycoumarins↗
PubMed1994

[Total cavopulmonary shunts. Short- and mid-term results apropos of 19 cases].

Experimental and clinical studies show that total cavopulmonary shunt operations may prevent certain complications of the Fontan atriopulmonary procedure. The authors have used the total cavopulmonary shunt instead of the Fontan procedure since February 1990. Nineteen consecutive patients were operated by three different surgical teams; 18 patients had undergone prior palliative surgery. The shunt was carried out by Puga's modified Kreutzer technique or by the construction of an extracardiac autologous pediculated pericardial tube. There were two deaths (10.5%) attributed to severe stenosis of the left pulmonary artery. The postoperative course was complicated in most of the 17 survivors but after a follow-up of 3 to 57 months (average 24.9 +/- 13.6 months) all were in the NYHA functional classes I (N = 15) or II (N = 2) with an arterial saturation over 85% in 15/17 cases and a cardiothoracic index less than 53% in 14/17 cases. All were in sinus rhythm. Doppler echocardiography showed no obstruction of the bypass. Pulmonary flow in 11 cases had a venous morphology. The function of the single ventricle was slightly depressed in 3 cases (2 of which were operated late, at 16 years of age). Catheterisation and cavography in 13 children showed uniform pressures in the cavopulmonary connection with no pressure gradient, except in 1 child. A right atrial'a'wave transmitted to the pulmonary arteries and inferior vena cava accompanied by retrograde vena cava flow was observed in 4 of the 6 cases with a Puga or modified Kreutzer procedure. Fenestration of the connection was closed by a Sideris button device in one case; reoperation was required in another.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

No evidence for linkage to the type 1 or type 2 neurofibromatosis loci in Noonan syndrome families.

A linkage analysis has been performed on 6 two-generation families with classical Noonan syndrome to determine whether the syndrome is linked to neurofibromatosis type 1 on chromosome 17q or to neurofibromatosis type 2 on chromosome 22q. A significantly negative location score was obtained between 10 cM centromeric to and 15 cM telomeric from the neurofibromatosis type 1 locus. A significantly negative lod score was obtained with a marker mapping within the region where neurofibromatosis type 2 is thought to be located. These data indicate that Noonan syndrome is not tightly linked to either neurofibromatosis type 1 or type 2.

Chromosome Mapping↗
PubMed1993

[Mid-term results of balloon percutaneous valvuloplasty in the treatment of aortic valve stenosis in children and adolescents].

Fourteen consecutive patients aged 10.2 +/- 4.2 years with congenital valvular aortic stenosis underwent percutaneous balloon aortic valvuloplasty (PBAV) which reduced the peak-to-peak LV-aortic pressure gradient from 81.2 +/- 16.7 mmHg to 27.5 +/- 12.5 mmHg and the maximal instantaneous Doppler gradient (Dopp G) from 70.0 +/- 13.4 mmHg to 31.4 +/- 12.3 mmHg. These 14 patients were followed up 3.6 +/- 1.1 years after PBAV. Control Doppler examination showed the Dopp G (34.8 +/- 15.4 mmHg) to be comparable to that measured just after PBAV (31.4 +/- 12.3 mmHg). One patient, the only one with a mediocre, immediate result, had to be operated 5.5 years after PBAV. Aortic regurgitation was observed on aortography before PBAV in 10 patients: it remained unchanged in 7 and was aggravated in 3 patients. Aortic regurgitation was observed for the first time after PBAV in 3 patients. At control Doppler examination, aortic regurgitation was present on color Doppler in all cases but was mild or minimal in 9 cases. In one patient, secondary aggravation of aortic regurgitation required aortic valve replacement (homograft) 3 years after PBAV. Four of the 16 PBAV (25%) were performed in these 14 patients were complicated by a femoral arterial thrombosis. This study shows that the good primary results of PBAV in the treatment of congenital valvular aortic stenosis in childhood and adolescence, are maintained at medium-term. The risk of creating severe aortic regurgitation is not completely negligible but does not seem to be out of proportion compared with surgical valvotomy.

Adolescent↗
PubMed1993

[Percutaneous angioplasty of aortic recoarctation: short- and mid-term results in 18 cases].

Between January 1986 and July 1992, 18 percutaneous angioplasties were performed in 18 consecutive patients with recoarctation of the aorta, who were aged 2 months to 29 years. Fifteen had been operated for coarctation of the aorta and 3 for interruption of the aortic arch. The diameter of the dilating balloon was the same, to 1 mm, as that of the healthy aorta, usually measured just proximal to the stenosis. There were 3 femoral artery thromboses; one small aneurysm which did not increase in size, and 1 hypertensive crisis in a child. The diameter of the stenosis increased by 42.39 +/- 34.24%, the gradient decreased from 41.39 +/- 14.58 mmHg to 23.7 +/- 16.30 mmHg and the Doppler gradient from 57.89 +/- 15.29 mmHg to 36.55 +/- 16.50 mmHg. Eight angioplasties, including 5 of the last 7 procedures, were considered primary successes by 2 criteria: increase of the diameter of the stenosis by at least 40% and a residual catheter gradient of less than 20 mmHg. The best results were obtained in severe, localised central stenoses. Sixteen patients were followed up for 2 to 69 months. Two were operated after failed angioplasty, without complications. No late aneurysms or restenoses were observed in the cases successfully dilated followed up clinically (7), by MRI (5) or catheterisation (2). In one case, aortography showed remodelling with normalisation of the aortic arch after 24 months. These results indicate that percutaneous angioplasty is a simple method of treating recoarctation of the aorta, which is most effective in severe stenoses: the immediate risk is low. The late risks of recoarctation and aneurysm justify systematic follow-up.

Adolescent↗
PubMed1992

Right ventricular overload and induced sustained ventricular tachycardia in operatively "repaired" tetralogy of Fallot.

The aim of the study was to evaluate the main predictors of the inducibility of sustained ventricular tachycardia (VT) in patients with repaired tetralogy of Fallot. Thirty-five patients (age 12 +/- 6 years) underwent right-sided cardiac catheterization, echocardiography, radionuclide angiography and ventricular stimulation; 10 had (group 1) and 25 had no (group 2) sustained VT. Group 1 patients were significantly older at the time of surgery and had longer follow-up periods (7 +/- 3 vs 4 +/- 4 years, p less than 0.02; and 12 +/- 4 vs 5 +/- 2 years, p less than 0.001, respectively). Right ventricular (RV) systolic pressure, end-systolic and end-diastolic normalized RV volumes were higher in group 1 (48 +/- 14 vs 38 +/- 11 mm Hg, p less than 0.05; 1.23 +/- 0.2 vs 0.86 +/- 0.17, p less than 0.001; and 2.35 +/- 0.37 vs 1.70 +/- 0.22, p less than 0.001, respectively). RV end-diastolic pressure, left ventricular and RV ejection fractions were similar in the 2 groups. A stepwise discriminant analysis was made to predict patients with inducible sustained VT (group 1): Time period from surgery to follow-up (p less than 0.001), normalized RV end-systolic volume (p less than 0.002) and RV systolic pressure (p = 0.01) were higher in group 1 and allowed classification of 90% of patients in group 1 and 96% in group 2.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗