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Biomedical subjects

J Kachaner

Publications and source records attributed to J Kachaner.

At least 109 records · Page 6Linked to original sources
PubMed1994

[Risk factors of coronary graft disease following heart transplantation in children].

Coronary disease after cardiac transplantation is a major medium and long-term complication in adult patients. In childhood, this is reputed to be rare and, therefore, the authors undertook a study to evaluate its incidence and the role of potential risk factors in this age group. The study included 30 children followed up at least one year after cardiac transplantation and investigated by at least one selective coronary angiography after the first postoperative year. Seventeen patients (57%) had a normal coronary angiography but 13 had coronary lesions (43%). The two groups were compared for age, sex, HLA groups of the donor-recipient couple, the duration of ischaemia of the transplants, cytomegalovirus serology, lipid profile, number of episodes of acute rejection that were treated, the necessity for steroid therapy for more than 3 months, and the blood pressure. The only significant differences, probably inter-related, were the number of rejections treated, greater in the group with coronary lesions (2.23 +/- 1.01 per patient) than in the group with normal coronary arteries (1.53 +/- 1.01 per patient) (p < 0.05) and the necessity of triple therapy with addition of prednisone, greater in the first group (9/13) than in the second (4/17) (p < 0.02). These results show that coronary disease after cardiac transplantation is as common and as early in children as in adults. They strongly suggest an important role of immunological factors. On the other hand, the authors' experience did not confirm the role of other potential risk factors.

Adolescent↗
PubMed1994

[Outcome of Wolff-Parkinson-White syndrome in children. Transesophageal study of anterograde permeability of the accessory pathway and of atrial vulnerability].

Twenty-nine children with the Wolff-Parkinson-White syndrome (WPW) were evaluated by transoesophageal electrophysiological studies to determine the quality of anterograde-conduction in the accessory pathway and the atrial vulnerability. The study group included 15 neonates, 1 to 30 days old, and 14 children from 5 to 15 years of age; Anterograde conduction through the bundle of Kent was tested by incremental transoesophageal atrial pacing and by the determination of the shortest conducted cycle with preexcited RR waves; bursts of atrial pacing were then used to try to trigger an atrial arrhythmia. In the group of the 15 neonates, 11 had accessory pathways capable of conduction to the ventricules at frequencies > 300/min (stimulation cycle < or = 2.00 ms) but no atrial arrhythmias could be induced. The older children had slower conduction in the accessory pathways with the shortest conducted cycle length > 200 ms in 11/14 cases; on the other hand, atrial fibrillation was easily induced in 4 children, all over 12 years of age. The risk of syncope by rapid conduction of an atrial arrhythmia through the accessory pathway is negligeable in young children, including those on digoxin. This study suggests that this low risk is explained more by the absence of atrial vulnerability than by the electrophysiological properties of the accessory pathways.

Arrhythmias, Cardiac↗
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

Aortic arch thrombosis in the neonate.

Two cases of neonatal aortic arch thrombosis are reported. One patient, who had ascending aortic thrombosis, died preoperatively. The other had reoperation and is alive and well at 6 months' follow-up. No obvious cause was found.

Adult↗
PubMed1993

Pediatric cardiac transplantation for congenital heart defects: surgical considerations and results.

Among 54 children who underwent 55 heart transplantations, 24 (44%) (mean age, 4.9 +/- 4.8 years; range, 9 days to 18 years) had congenital defects with the following diagnoses: single-ventricle variants (6), hypoplastic left heart syndrome variants (5), transposition complex (6), and miscellaneous defects (7). Twenty patients (83%) had undergone 43 prior operations. Additional surgical procedures included repositioning of transposed great arteries (11), reconstruction of the aortic pathway (4), reconstruction of the pulmonary pathway (8), correction of situs inversus (1), and correction of anomalous pulmonary (1) or systemic (1) venous drainage. Reconstructive procedures were performed using donor or recipient tissue or both. There were six early deaths (hyperacute rejection, 1 patient; pulmonary hypertension, 1; graft failure, 2 patients; infection, 2) and six late deaths (sudden death, 2; chronic rejection, 2; nonspecific graft dysfunction, 1; lymphoproliferative disease, 1). The survival rate was 43% +/- 12% at 3 years. No deaths were related to surgical technique. Survival was not significantly different in pediatric recipients with cardiomyopathy (67% +/- 9%; p = 0.22). Accelerated coronary artery disease was noted in 4 operative survivors (22%; 70% confidence limits, 12% to 36%). All late survivors were free from cardiac symptoms after a mean follow-up of 34 +/- 24 months (range, 6 to 71 months). Based on this study, we reached three conclusions. (1) Careful planning of both harvesting and transplantation procedures allows heart transplantation in recipients with congenital heart diseases. (2) The surgical technique may be demanding, but the early risk is not increased.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

[Catecholamine induced ventricular tachycardia: a cause of severe syncope during adolescence].

A 15-year-old female teenager had recurrent syncopes and had been unsuccessfully treated for 6 years for seizures and hysteria. Syncopes were always triggered by emotions, or efforts, but electrocardiograms were normal between the episodes. A 24-hour-monitoring during a syncope, and provocative tests (exercise testing and isoprenaline administration) showed severe ventricular arrhythmias with premature polymorphous beats, followed by ventricular tachycardia and then ventricular fibrillation. These "catecholamine-induced" ventricular tachycardias are very rare but are always fatal without treatment. Syncopes are stress-induced and the diagnosis is almost always delayed, because the patients have a normal electrocardiogram, with normal QT interval. The arrhythmia appears beyond a "threshold" sinus rate and is easily reproducible by exercise testing. Betablockers are the only efficient treatment to prevent sudden death.

Adolescent↗
PubMed1993

[Extensive fibrous endocarditis as first manifestation of systemic lupus erythematosus].

BACKGROUND: Cardiac abnormalities, such as myocarditis, pericarditis or verrucous endocarditis (Libman-Sacks endocarditis) occur in about one third of patients with systemic lupus erythematosus. This study describes an unusual aspect of endocardial involvement. CASE REPORTS: Case no. 1: A 14 year-old girl was admitted 3 months after acute hemichorea because of heart failure plus biological inflammatory findings. Echocardiography showed mitral insufficiency with enlargement of the left atrium and ventricle. There was some infiltration involving the endocardium of the left ventricle, the chordae tendinae and the mitral valve. The titres of anti-DNA and anti-nuclear antibodies were elevated while the serum hemolytic complement was depressed. Skin biopsy showed IgG, IgM and C1q deposits along the dermoepidermal junction. Corticosteroids, diuretics and vasodilator drugs failed to completely cure the heart failure; the mitral insufficiency required mitral valve replacement 21 months later. Pathological examination showed extended fibrotic changes of the endocardium. Case no. 2: A 4 year-old boy was admitted for acute heart failure due to mitral insufficiency, associated with biological inflammatory findings. Echocardiography showed mitral insufficiency and enlarged left atrium and ventricle. Anti-DNA and anti-nuclear antibody titres were elevated. The patient was given antibiotics followed by corticosteroids and immunosuppressive drugs. The persistence of the mitral insufficiency required mitral valve replacement 7 months later. Pathological examination showed fibrotic changes of the endocardium. Exacerbation of the inflammatory process was seen 2 months after surgery, with development of diffuse proliferative lupus nephritis. The patient died of kidney failure and neurological complications, 44 months after cardiac surgery. CONCLUSION: In both patients, the systemic lupus erythematosus was revealed by endocardial involvement, a complication that is usually seen later. The endocardium changes responsible for mitral insufficiency and requiring valve replacement in these two cases were different from those described as verrucous endocarditis in classical forms of the disease.

Adolescent↗
PubMed1993

[Perforation-dilatation of pulmonary atresia with intact interventricular septum in neonates and infants].

Sixteen children (14 neonates less than 1 week old and 2 infants aged 3 and 6 months) had a "favorable" type of pulmonary atresia with an intact interventricular septum in which the hypoplasia of the right ventricle was mild and the cavity tripartite with a well developed infundibulum arriving in contact with a good-sized pulmonary artery from which it was separated by a totally or almost totally imperforate dome. They underwent a procedure associating an infusion of prostaglandin. E1 and an attempted pulmonary valve disobliteration by interventional catheterisation: needle puncture followed by balloon dilatation. There were 4 failed procedures (impossible puncture or dilatation), only one of which in the last 10 cases. The outcome of the 12 primary successes was related to the rapidity of recovery of right ventricular diastolic function: 7 patients were cured within a few days or weeks with prostaglandin therapy: 5 children required surgical anastomosis with a longer recovery period--3 cures but 2 deaths. Overall, there were two myocardial effractions without serious complications and 1 enterocolitis which was long-lasting but eventually cured. Two mild residual stenoses were redilated. In conclusion, the puncture-dilatation technique may be used instead of surgical valvectomy in favorable forms of pulmonary atresia with intact septum in the neonate. With experience, it was possible to remove the obstruction in 9 out of 10 cases with a minimum of complications. It is the compulsory first stage to complete cure, the probability and rapidity of which depend on recovery of right ventricular compliance.

Angiocardiography↗
PubMed1993

[Cavopulmonary shunts in the treatment of univentricular heart diseases in children. An experience of 60 cases].

Sixty children with a complex cardiac malformation consisting of a single functional ventricle and a protected pulmonary circulation, previously palliated by one or several Blalock anastomoses (40 cases) underwent a cavopulmonary shunt procedure. All but one had an excellent hemodynamic status: ventricular end diastolic pressure < 15 mmHg, mean pulmonary pressure < 20 mmHg, pulmonary vascular resistance < 3 units and a Mayo Clinic index (a combination of these parameters and pulmonary and systemic blood flow) < 4. The shunt was complete from the outset in the 27 most favorable cases which did not require any other surgical procedure. There were 2 immediate failures which necessitated reducing the reconstruction to a partial shunt; 9 cases were complicated by thrombosis of the intercaval connection (2 case, 1 death), by neurological complications (2 cases, 1 death), by chronic serous effusions (5 cases): of the 21 survivors followed up for a maximum of 54 months (average 28 +/- 9 months), 18 were well and 2 handicapped by venous stasis. The shunt was partial in 33 cases, especially in 17 cases because it was necessary to operate the pulmonary branches, the subaortic area, or an atrioventricular valve; there was no immediate mortality but 5 complications which were related to an associated procedure in 3 cases. There were no complications in 28 cases: of the 30 children followed up an average of 24 months, there were 3 secondary degradations (2 deaths and 1 cardiac transplantation), 10 shunts completed 2 to 32 months later with no deaths and 8 excellent results, and 17 children waiting for more favorable conditions.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

[Congenital coronary-cardiac fistula. Diagnosis by color Doppler echocardiography in an infant].

The authors report the case of a 2 month old child in whom a coronary artery fistulae was diagnosed by colour Doppler echocardiography. Routine two-dimensional echocardiography showed a very dilated right coronary artery. Turbulent flow was detected in this vessel by pulsed Doppler echocardiography. Colour Doppler showed the fistulous connection to the inferior wall of the right ventricle. Until recently, this condition could only be diagnosed by selective angiography and coronary arteriography. Although there have been few reports in the literature, colour Doppler echocardiography would seem to be a significant advance in non-invasive diagnosis of abnormal connections of the coronary arteries. It allows the differential diagnosis of coronary aneurysm, ectopic coronary arteries and sinus of Valsalva aneurysms to be excluded. The patients can be followed up by colour Doppler echocardiography and anatomic information can be obtained to guide surgery, notably the site of drainage of the fistula. Coronary artery fistulae presenting clinically with a continuous murmer atypically situated for a patent ductus arteriosus are difficult to detect by conventional echocardiography and usually required cardiac catheterisation and angiography. Color Doppler echocardiography is a valuable non invasive diagnostic tool for this condition. The others report the case of a coronary artery cardiac fistula in a neonate diagnosed by color Doppler echocardiography.

Age Factors↗
PubMed1992

Heart transplantation in children: mid-term results and quality of life.

From 1987 to 1991, heart transplantation was undertaken in 49 infants and children with either end-stage cardiomyopathies (28 patients) or severe congenital heart disease (21 patients including 16 having already been surgically but unsuccessfully treated). Their age ranged from 13 days to 15 years (mean = 4.5 +/- 4.2 years; median = 2.5 years). There were 12 early and 7 late deaths (overall mortality = 38%), mainly due to graft dysfunction, acute or chronic rejection, and infectious complications, mostly viral. Optimal criteria in selecting both donors and recipients are crucial to reduce early mortality and should never be transgressed despite the critical shortage of organs. The actuarial probability of survival was 64% at 1 year and 57% at 5 years. Our 30 mid-term survivors (62%) were submitted to a close follow up programme which includes endomyocardial biopsies, even in the very young, since non invasive criteria failed to mark every rejection episode. Maintenance therapy was always steroid-free to start with (cyclosporin+azathioprine) but in almost one half of our oldest survivors, it failed to avoid rejection and we had to add low-dose oral steroids for at least several months. Epstein-Barr virus related lymphoproliferations occurred in four patients, two of whom died and two recovered with specific therapy. Renal function was closely monitored: tubular and interstitial lesions were found on renal biopsies and were associated with moderate functional changes. The quality of life of the children who survived heart transplantation was considered as near normal in a little more than one half of the cases but many issues (late coronary disease, drug toxicity, long-term compliance to follow up and therapy) remain significant concerns for the future.

Adolescent↗
PubMed1992

Prolonged QT interval in neonates: benign, transient, or prolonged risk of sudden death.

To determine the factors relating to prognosis, the records of 15 neonates with persistent prolongation of the QT interval on the electrocardiogram after the fourth day of life were reviewed. Patients were admitted for symptoms (syncope, cardiac failure, or seizures), abnormal auscultation with an irregular heart rate or bradycardia, or because of a family history of a long QT syndrome. All infants had a long QTc, ranging from 0.46 to more than 0.70 second. Eight patients who had a QTc over 0.60 second developed severe ventricular arrhythmias (torsades de pointes, ventricular tachycardia) or second-degree AV block. Twelve of 15 were treated with beta-blocking agents, combined with ventricular pacing in five cases. Four infants died in the first month of life; they all had a very long QT interval and had experienced ventricular arrhythmias and AV block. Six children are still being treated with beta-blocking agents for the long QT syndrome and are doing well. In five infants, electrocardiographic abnormalities were transient and the QT interval returned to normal within 1 year. Therefore (1) prolongation of the QT interval in neonates may be transient or may represent an early form of the long QT syndrome and (2) the length of the QT interval may provide data on prognosis: those with a QTc less than 0.50 second returned to normal; those with a QTc greater than 0.60 second were associated with severe arrhythmias and four of eight infants died.

Adrenergic beta-Antagonists↗
PubMed1992

[Rhythmogenic cardiomyopathies of atrial origin in children. Myth or reality?].

Incessant, rapid, supraventricular tachycardia may be complicated by cardiac failure with ventricular dilatation and hypokinetic wall motion on echocardiography: so-called tachycardia-induced cardiomyopathy. The diagnosis is simple when the cardiac rhythm is not sinus rhythm. The authors report the cases of 4 children aged 7 months to 12 years, referred for diagnosis and treatment of apparently primary cardiomyopathy. The findings of spontaneous or vagally-induced atrioventricular conduction defects, a permanently rapid atrial rhythm though influenced by 24 hour variations, or periodic abnormal rate increases, suggested myocardial dysfunction due to an ectopic atrial tachycardia. This was an essential step in management as the control of the tachycardia by amiodarone or betablocker therapy resulted in regression of symptoms and normalisation of left ventricular function. However, some atrial tachycardias are very resistant to medical treatment and, in such cases, there should be no hesitation in using more radical approaches, surgery or ablation, even and especially in patients with severe cardiac failure. In conclusion, apparently primary dilated cardiomyopathy in children may be due to chronic atrial arrhythmia and it is essential to perform at least Holter monitoring in order not to miss this diagnosis.

Adrenergic beta-Antagonists↗
PubMed1992

[Results of the surgical repair of branch pulmonary artery stenosis in tetralogy of Fallot].

This study was based on the follow-up of 55 patients with tetralogy of Fallot and operated for branch pulmonary artery stenosis. Twenty two patients were followed up clinically (Group I): 91% of the patients were asymptomatic at the end of the first operative year. Thirty three patients (Group II) underwent control catheter studies after an average of 2.5 years after complete repair: only 70% of these were asymptomatic at 1 year; 8 were reoperated after an average of 3.6 years. The surgical result could only be evaluated by control catheter studies. The results were therefore based on the data obtained from Group II: this selection resulted in a pessimistic bias as the outcome in the two groups was significantly different. The stenoses were congenital and/or iatrogenic. They were located on the left branch (55%), the right branch (9%), the bifurcation (24%), separately on the two branches (12%). The diversity of the operative techniques and materials used reflects the difficulty of this surgery. The cumulative results were good in 33% of cases, average in 28% and poor in 39%. The results were better in isolated branch stenosis than in stenosis of the bifurcation, though not statistically significant. The results were related to age, body weight, the type, the site, the length, the association of stenoses and the material used. Significant predictive factors for a good result were: Gore-Tex (p less than 0.05) and pericardial pedicle (p less than 0.005). The average follow-up of patients with the latter type of patch was only 2 years. These results require confirmation by studies of larger numbers of patients followed up for a longer period.

Cardiac Catheterization↗
PubMed1992

[Enzymatic activities of the mitochondrial respiratory chain in child cardiomyopathies. 34 cases prospectively studied by endomyocardial biopsy].

The arguments in favour of mitochondrial pathology of certain childhood cardiomyopathies (multi tissue involvement, lactic acidosis, histochemical abnormalities of skeletal muscle) are indirect and may be absent in isolated cardiomyopathy. The authors therefore set up a prospective study of enzyme activity of the mitochondrial respiratory chain directly by endomyocardial biopsy. Fifty children aged 2 months to 16 years were included. Thirty four had cardiomyopathy which was dilated and hypokinetic with thin walls in 21 cases, restrictive in 2 cases, and hypertrophic in 11 cases; the remaining 16 children had either normal hearts (13 catheterised for other reasons) or myocardial hypertrophy due to pulmonary or aortic stenosis (3 cases). Both ventricles were evaluated in 3 cases; macro-surgical biopsies were obtained in 6 cases and skeletal muscle biopsy was obtained in 9 cases. The results indicate the method to be reliable with no difference between the micro and macro biopsies. The absolute values of enzyme activity were too variable to serve as quantitative parameters but some ratios of activity were remarkably stable and allowed a qualitative assessment which was all the more accurate when identical values were obtained in the myocardium, skeletal muscle and liver. The mitochondrial respiration was independent of ventricular pressures and of the type (right or left) of ventricle. Enzyme activity was nearly always normal in dilated cardiomyopathy (20/21) which suggests that it was unaffected by dilatation of the heart and by abnormal myocardial contractility. The results could be normal in myocardial hypertrophy and in valvular stenosis and in over half the cases of hypertrophic cardiomyopathy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Modified Blalock Taussig shunt anastomosis in a three month old child with pulmonary stenosis: embolization therapy.

A case of transcatheter occlusion of a modified Blalock-Taussig (BT) shunt with a detachable balloon is described. A three month old boy with pulmonary atresia with intact ventricular septum had a repair consisting in valvotomy and a modified BT. This palliative aorticopulmonary shunt created congestive heart failure. As an alternative to surgery, a detachable balloon was used to occlude the BT shunt.

Anastomosis, Surgical↗