[Evaluation of an educational program for oral anticoagulation in children with the INR home-monitoring CoaguChek XS(®)]

OBJECTIVE

To assesses the results of our education program relative to anticoagulation therapy and self-monitoring of INR.

MATERIALS AND METHODS

All children treated with oral anticoagulation therapy and followed using INR self-monitoring in Tours and Nantes, France, were included. A questionnaire on the treatment and its management was sent to the patients and their family. We analyzed the quality of anticoagulation using the proportion of INR within the target range.

RESULTS

Thirty-three children were included, with a mean age of 10.9years. Thirty-one questionnaires could be analyzed. Insufficient knowledge on the treatment objective and risks, the INR target range, and the interpretation of the INR was observed. We found 65.8% of INRs within the target range. The proportion of INRs within the target range was better with the INR self-testing than with the laboratory test (69.7% vs. 49.1%, P=0.003). There was no major complication observed during the study period. A moderate correlation (K=0.57) was noted between the INRs measured with the point-of-care monitor and the laboratory test on the same day.

CONCLUSION

However, home-monitoring of oral anticoagulation therapy increases the quality of anticoagulation. Both education and the training program need improvement in order to provide patients and their families with better knowledge on anticoagulation therapy.

Population pharmacokinetics of domperidone in preterm neonates

PURPOSE

A population pharmacokinetic analysis was performed to define domperidone pharmacokinetic parameters in preterm neonates, as no pharmacokinetic data are available in this population.

METHODS

An oral domperidone solution was administered (0.75 mg/kg per day) in 32 preterm neonates (64 samples). Domperidone plasma concentration was measured by high-performance liquid chromatography (HPLC) assay, and a one-compartment model with first-order absorption was fitted to the data using NONMEM version V level 1.1.

RESULTS

The mean peak and trough plasma concentration values of domperidone were, respectively, 25.3 +/- 20.5 ng/ml and 15.4 +/- 11.4 ng/ml (mean +/- standard deviation). The pharmacokinetic parameters (interindividual variability%) were clearance (Cl/F) = 0.92 L/h (51.6%), volume of distribution (Vd/F) = 0.405 L (68%), and absorption constant rate (Ka) = 0.0843 h(-1) (55.8%). The clearance is not lower than values reported in adults. No influence of covariates (postnatal age, prematurity, weight, gender) on domperidone pharmacokinetic parameters was found.

CONCLUSION

This pilot study designed with a limited sampling strategy showed that domperidone plasma concentrations were consistent with those reported in adults, suggesting that domperidone dosage regimen currently used in preterm neonates is suitable.

[Septal alcoholisation of hypertrophic obstructive cardiomyopathy in childhood]

The authors report a case of septal alcoholisation in a 6 year old child with hypertrophic obstructive cardiomyopathy responsible for congestive cardiac failure despite optimal betablocker therapy. The indication was retained in a context of mucoviscidosis complicated by multiresistant bacterial infection. At catheterisation, the dominant septal artery was identified and an alcoholisation was performed by the classic technique described in adults. The immediate result was satisfactory with regression of the signs of cardiac failure and reduction of 70 mmHg of the maximal instantaneous pressure gradient (from 160 to 90 mmHg). However, 10 months later, the signs of right heart failure reappeared with a partial increase in the maximal instantaneous pressure gradient (100 mmHg) leading to surgical myectomy while the patient's condition had considerably improved from the pulmonary point of view. Septal alcoholisation would appear to be a therapeutic alternative in children especially in cases with a temporary or permanent contraindication to conventional surgery.

Prophylactic ibuprofen versus placebo in very premature infants: a randomised, double-blind, placebo-controlled trial

BACKGROUND

Patent ductus arteriosus is a common complication of prematurity that frequently requires surgical or medical treatment. The benefit of prophylactic treatment by indometacin, a cyclo-oxygenase inhibitor, remains uncertain compared with curative treatment. This benefit could be improved with ibuprofen, another cyclo-oxygenase inhibitor with fewer adverse effects than indometacin on renal, mesenteric, and cerebral perfusion. We aimed to compare prophylactic and curative ibuprofen in the treatment of this abnormality in very premature infants.

METHODS

We did a randomised controlled trial in infants younger than 28 weeks of gestation, who were randomly assigned to receive either three doses of ibuprofen or placebo within 6 h of birth. After day 3, symptomatic patent ductus arteriosus was treated first by open curative ibuprofen, then back-up indometacin, surgery, or both. The primary endpoint was need for surgical ligation. Analysis was per protocol.

FINDINGS

The study was stopped prematurely after 135 enrollments because of three cases of severe pulmonary hypertension in the prophylactic group. 65 infants received prophylactic ibuprofen, and 66 received placebo. Prophylaxis reduced the need for surgical ligation from six (9%) to zero (p=0.03), and decreased the rate of severe intraventricular haemorrhage from 15 (23%) to seven (11%) (p=0.10). However, survival was not improved (47 [71%] placebo vs 47 [72%] treatment, p=1.00), because of high frequency of adverse respiratory, renal, and digestive events.

INTERPRETATION

In premature infants, prophylactic ibuprofen reduces the need for surgical ligation of patent ductus arteriosus, but does not reduce mortality or morbidity. Therefore, it should not be preferred to early curative ibuprofen.

Contamination of a milk bank pasteuriser causing a Pseudomonas aeruginosa outbreak in a neonatal intensive care unit

An environmental investigation and a cohort study were carried out to analyse an outbreak of infection caused by a serotype O10 Pseudomonas aeruginosa in a neonatal intensive care unit. Thirty one cases of infection were recorded, including four lethal ones. The outbreak was stopped by eradicating the environmental sources: a contaminated milk bank pasteuriser and bottle warmer.

[Transient left myocardial dysfunction: a cause of neonatal hypoxemia]

Refractory hypoxemia in the newborn requires an accurate diagnostic investigation for an optimal and prompt management.

CASE REPORT

After a short delivery, a post-term newborn developed a severe hypoxemia with patchy pulmonary alveolar opacities and systolic right-to-left extrapulmonary shunting through the ductus arteriosus. Echocardiography ruled out a cardiac malformation and showed dilated left atrium with left-to-right shunting by the ovale foramen due to left ventricular dysfunction. Inotropic support associated with mechanical ventilation allowed a rapid improvement.

CONCLUSION

A pathophysiological analysis is needed in case of severe neonatal hypoxemia. Doppler ultrasound is a non invasive and rapid method allowing the adjustment of the therapeutic strategy.

Development of baroreflex control of heart rate in preterm and full term infants

AIM

To study baroreflex maturation by measuring, longitudinally, baroreflex sensitivity in preterm (gestational age 24-37 weeks) and full term infants.

METHODS

Baroreflex sensitivity was quantified once a week, one to seven times, by a totally non-invasive method.

RESULTS

Baroreflex sensitivity at birth was lower in the preterm infant and increased with gestational age. It also increased with postnatal age, but the values for the preterm infants at term still tended to be lower than the values for full term babies.

CONCLUSION

Baroreflex control of heart rate is present in the premature infant, but is underdeveloped and increases with postnatal age. Ex utero maturation seems to be delayed compared with in utero maturation assessed by full term values. These results may reflect sympathovagal imbalance in preterm infants and could identify a population more vulnerable to stress.

Pulmonary hypertension after ibuprofen prophylaxis in very preterm infants

We report three cases of severe hypoxaemia after ibuprofen administration during a randomised controlled trial of prophylactic treatment of patent ductus arteriosus with ibuprofen in premature infants born at less than 28 weeks of gestation. Echocardiography showed severely decreased pulmonary blood flow. Hypoxaemia resolved quickly on inhaled nitric oxide therapy. We suggest that investigators involved in similar trials pay close attention to pulmonary pressure if hypoxaemia occurs after prophylactic administration of ibuprofen.

Partial anomalous pulmonary venous connection: correction by intra-atrial baffle and cavo-atrial anastomosis

The creation of intracaval conduits to repair partial anomalous pulmonary venous connection of the right lung into the superior vena cava can be complicated by arrhythmias and superior vena cava and pulmonary vein obstruction. An intra-atrial baffle, combined with cavo-atrial anastomosis, has been proposed to avoid these complications. The authors report their recent experience with this operative technique. From January 1997 to December 2000, 7 patients with a mean age of 13.5 +/- 9 (2-31) years were operated according to this technique. Only one child did not have an associated atrial septal defect. The mean number of pulmonary veins connected to the superior vena cava was 2.5 +/- 0.5. The immediate postoperative course was uneventful for the seven patients. The mean follow-up was 20 +/- 17 months. No patient developed arrhythmia or superior vena cava or pulmonary vein obstruction at echocardiography. This surgical technique appears to constitute an attractive alternative when pulmonary veins drain abnormally into the superior vena cava above the cavo-atrial junction.

[Osler endocarditis of a ventricular septal defect in a 21-month old child]

The authors report a case of streptococcus mitis endocarditis of a ventricular septal defect in a 21 months old girl admitted for necrotic purpura of the lower limbs and a history of general ill health and pyrexia for two months. The severity of this case of endocarditis was illustrated by the importance of the vasculitis, the biological signs of infection (disseminated intravascular coagulation), and the size of the vegetation. The vegetation extended from the tricuspid valve as far as the pulmonary orifice which was partially obstructed, causing signs of right ventricular failure. The portal of entry was not found. Surgical ablation of the vegetation with tricuspid valvuloplasty was necessary after 48 hours of antibiotherapy. The outcome after one year's follow-up is good. The diagnosis of bacterial endocarditis must be considered even in very young children, especially those with congenital heart disease, and, in particular, ventricular septal defect.

[Preoperative mortality in transposition of the great vessels]

The aim of the study was to report the incidence and causes of preoperative deaths in isolated transposition of the great vessels and to describe the clinical findings in these neonates.

PATIENTS AND METHODS

In five French centers of pediatric cardiology, data of all the neonates with isolated transposition of the great vessels who died before arterial switch operations between January 1986 and June 1996 were obtained from reviewing hospital files, echocardiography records and autopsy reports.

RESULTS

Among 199 neonates with transposition of the great vessels, 20 (9.9%) died before surgery. The death was related to intracranial haemorrhage in one premature neonate, severe and early hypoxemia in 13 full-term patients (group A) and later sudden collapse in six patients (group B). In group A, the symptoms occurred within 20 minutes after the birth and included cyanosis (n = 12), acute respiratory distress (n = 8), and shock (n = 4). Despite assisted ventilation (n = 13), bicarbonate infusion (n = 12), prostaglandin E1 (n = 7), inotropic drugs (n = 5) and balloon atrioseptostomy (n = 7), death occurred at the median age of five hours. The patent foramen ovale was absent or tiny in ten patients, normal in one patient and not specified in two patients. The ductus arteriosus was patent in ten patients and not specified in three patients. In group B, the neonates were initially in a good hemodynamic condition. Unexplained death occurred between two and five days after the birth: one infant with a large patent foramen ovale did not receive prostaglandin E1, four patients died a few hours after an angiographic study or a balloon atrioseptostomy was performed in a catheterization laboratory, and one child suffered from a cerebral anoxia due to a tightened cord.

CONCLUSION

We conclude that the high preoperative mortality rate in isolated transposition of the great vessels is mainly due to absent or small atrial shunt. These findings suggest that only prenatal diagnosis of transposition of the great vessels with immediate balloon atrioseptostomy could avoid a fatal outcome.

Perinatal myocardial DNA and protein changes in the lamb: effect of cortisol in the fetus

Myocardial growth during fetal life is accomplished by proliferation of the number of myocytes (hyperplasia). Shortly after birth, normal growth of the heart is predominantly due to increase in cell size (hypertrophy), and myocytes largely lose the capability to replicate. This change is characterized by a decrease in myocardial DNA concentration and an increase in protein/DNA concentration ratio. Among many of the events associated with birth is an increase in plasma cortisol concentrations in the few days before delivery of the fetus. To determine the possible role of cortisol in the postnatal change in myocardial growth, we measured DNA and protein concentrations in the free walls of the left (LV) and right (RV) ventricles in normal fetal lambs, normal newborn lambs, and in fetal lambs in which cortisone was infused for 72-80 h into the left coronary artery, which we showed does not perfuse the RV free wall. Normally, fetal RV DNA is higher than LV DNA concentration, and DNA/protein ratio is lower in RV than in LV. It is suggested that this could be related to the greater load on the RV. Postnatally, protein concentrations increase progressively, but DNA remains the same in both ventricles, and protein/DNA ratios increase. Cortisol, infused to achieve normal prenatal levels in LV myocardium, markedly decreases LV DNA without affecting RV DNA concentrations. The present study indicates that cortisol inhibits myocyte replication and that cortisol simulates the change in myocardial growth pattern normally occurring after birth. It raises concerns regarding prenatal administration of glucocorticoids to mothers to mature the fetal lungs before preterm delivery.

Mechanisms of adrenomedullin-induced increase of pulmonary blood flow in fetal sheep

Mechanisms of adrenomedullin-induced increases in fetal pulmonary blood flow were examined in 19 near-term fetal sheep using four key blocker drugs: nitric oxide synthase inhibitor (N(omega)-nitro-L-arginine), calcitonin gene-related peptide (CGRP) receptor blocker, ATP-dependent potassium (K(ATP)) channel blocker (glibenclamide), and cyclooxygenase inhibitor (indomethacin). Catheters were inserted into the left pulmonary artery and superior vena cava to administer drugs and into the main pulmonary and carotid arteries to measure pressures and heart rate. An ultrasonic flow transducer was placed around the left pulmonary artery to measure flow continuously. Adrenomedullin (mean 1.06 microg/kg) was injected into the left pulmonary artery before and after infusion of N(omega)-nitro-L-arginine (mean 96.5 mg/kg, n = 6), glibenclamide (mean 11.8 mg/kg, n = 6), CGRP receptor blocker (mean 312.0 microg/kg, n = 6), and indomethacin (mean 1.7 mg/kg, n = 8). Blockade was confirmed by appropriate agonist injection. The adrenomedullin-induced response in left pulmonary artery blood flow was inhibited by N(omega)-nitro-L-arginine (inhibition rate 99%) and significantly attenuated by glibenclamide (inhibition rate 44%); however, no significant changes were found with CGRP receptor blocker or indomethacin (inhibition rate 0 and 17%, respectively). The responses of the main pulmonary and carotid arterial pressures were similarly affected by those blockers. Our data suggest that in the fetal pulmonary circulation, the adrenomedullin-induced increase in pulmonary blood flow depends largely on nitric oxide release and partly on K(ATP) channel activation, and does not involve the CGRP receptor or a cyclooxygenase-mediated mechanism.

Persisting spongy myocardium. A case indicating the difficulty of antenatal diagnosis

Persisting spongy myocardium (also known as noncompaction of the ventricular myocardium) is a rare and special form of cardiomyopathy. The few cases reported in the literature were detected postnatally and involved a high rate of cardiovascular complications. This anomaly of endomyocardial morphogenesis, which occurs during the embryonic phase at the stage of cardiac partitioning, is characterised by an excessive number of prominent trabeculae and by intertrabecular recesses within the myocardial wall. Antenatal detection is difficult in the absence of an associated malformation, which is the general situation. We report a case of antenatal cardiomyopathy which led to therapeutic abortion. The diagnosis of persisting spongy myocardium was made during fetopathologic examination.

Doppler echocardiographic assessment of pulmonary blood flow in healthy newborns

The aim of this study was to determine interobserver variation in Doppler assessment of mean left pulmonary arterial flow velocity, and its normal values during the first 24h of life. The interobserver variation was determined by a Bland and Altman analysis of the values of mean velocity measured in 21 newborns by 2 observers. Then, normal values of mean velocity were measured in 15 newborns at 5, 10 and 15 min of life in the delivery room, and in 14 other newborns at 1, 2, 6, 12 and 24h of life in the nursery unit. The interobserver variation was found to be acceptable. Mean velocity had a few variations within the first 24 h, but remained consistently above 20 cm s(-1). In conclusion, mean velocity values below 20 cm(-1) suggest low pulmonary blood flow.

[Neonatal hypoxemia due to misaligned pulmonary vessels with alveolar capillary dysplasia]

BACKGROUND

Refractory hypoxemia in the newborn requires a precise diagnostic investigation for optimal and fast management.

CASE REPORT

A full term newborn presented with refractory hypoxemia associated with radiologically clear lung fields and extrapulmonary shunt. Echocardiography ruled out a cardiac malformation. The persistence of hypoxemia despite treatment of the extrapulmonary shunt and the absence of parenchymatous pulmonary disease led to suspect misaligned lung vessels with alveolar capillary dysplasia. This diagnosis was confirmed by post mortem microscopic examination of the lung.

CONCLUSION

The diagnosis of misaligned lung vessels with alveolar capillary dysplasia can be suspected on clinical features. The disposition of pulmonary veins must be checked to recognize this disease in case of neonatal death with pulmonary hypertension.

Oxygen cost of breathing and weaning process in newborn infants

Newborn infants may have a high oxygen cost of breathing (OCB) at the time of being weaned from mechanical ventilation. We hypothesized that this increase in oxygen consumption (V'O2) could be reduced by using certain weaning ventilatory modes. We designed a study to assess V'O2 during three weaning ventilatory modes: patient triggered ventilation, synchronous intermittent mandatory ventilation (SIMV) and continuous positive airway pressure in 16 newborn infants before being weaned from mechanical ventilation In seven infants whose OCB was high. V'O2 was not significantly different between CV and PTV (8.9+/-0.6 versus 9.5+/-0.8, respectively) whereas it tended to increase to 10.8+/-1.1 mL x min(-1) x kg(-1) during SIMV and increased significantly to 11.9+/-0.8 mL x min(-1) x kg(-1). In the other nine infants whose OCB was normal, no significant variation of V'O2 was observed. Patient triggered ventilation was a weaning ventilatory mode that significantly reduced the increase in oxygen consumption observed in infants with a high oxygen cost of breathing, as compared to synchronous intermittent mandatory ventilation or continuous positive airway pressure. Further investigations in newborn infants with a high oxygen cost of breathing should be performed prior to routine use of patient triggered ventilation.

Feasibility of using finger arterial pressure in neonates

The feasibility of using a Finapres device to reproduce the beat to beat signal of arterial blood pressure in eight neonates was assessed and compared with intra-arterial measurement of arterial blood pressure in the umbilical artery, using a catheter. The two methods gave similar results. Continuous recording of arterial blood pressure in neonates using Finapres is feasible and reliable.

Adrenomedullin increases pulmonary blood flow in fetal sheep

We studied the effects of exogenously administered adrenomedullin on fetal pulmonary arterial blood flow in near-term fetal sheep. The hemodynamic effects of a single injection of adrenomedullin into the left pulmonary artery were compared with those of acetylcholine; the effects of repeated injections of adrenomedullin were also studied. In seven unanesthetized fetal sheep, catheters were inserted into the left pulmonary artery to administer drugs, and into the main pulmonary and carotid arteries to measure pressures. An ultrasonic flow transducer was placed around the left pulmonary artery to measure flow continuously. A single 5-microgram injection of adrenomedullin (1.90 +/- 0.35 micrograms/kg of fetal weight) increased pulmonary arterial blood flow significantly, from 17 +/- 10 to 120 +/- 21 mL/min (p < 0.001). Two micrograms of acetylcholine (0.74 +/- 0.14 microgram/kg of fetal weight) also increased left pulmonary arterial blood flow, from 18 +/- 16 to 113 +/- 37 mL/min, but the effect of adrenomedullin on flow was more prolonged than was that of acetylcholine. Additionally, adrenomedullin and acetylcholine similarly decreased mean pulmonary arterial pressure by 11 and 16%, respectively, but adrenomedullin did not decrease mean carotid arterial pressure to the same degree as acetylcholine (2 versus 19%, respectively). Five sequentially repeated injections of adrenomedullin, once every 5 min, increased left pulmonary arterial blood flow significantly in a stepwise manner without significantly changing heart rate or mean pulmonary and carotid arterial pressures. We conclude that exogenously administered adrenomedullin is a pulmonary vasodilator in fetal sheep and has the ability to increase pulmonary blood flow significantly; there is less effect on the systemic circulation. This finding might be important in considering the therapeutic use of this peptide in the management of persistent pulmonary hypertension in the perinatal period.

Assessment of spontaneous baroreflex sensitivity in neonates

AIMS

To determine whether it is possible to assess baroreflex sensitivity in neonates by studying only spontaneous variation in systolic blood pressure and heart rate.

METHODS

ECG and non-invasive blood pressure signals were continuously studied in 14 preterm neonates (term 29-32 weeks) and five term neonates (term 40-41 weeks). Non-invasive blood pressure measures were obtained using a Finapres placed around the child's wrist. Both signals (ECG and blood pressure), sampled at 400 Hz, were digitised by an A/D converter and stored in a binary mode on magnetic disk. An inhouse software QRS detection algorithm was used to define R peaks of the QRS complexes with an accuracy greater than 2 ms. Four 4 minute periods were recorded in each infant. The slope of the linear regression of RR intervals versus systolic blood pressure was calculated in each period and the mean value of the four slopes was then considered as the index of baroreflex sensitivity (in ms/mm Hg) in each neonate.

RESULTS

Spontaneous baroreflex sensitivity was lower in preterm neonates than in term neonates (mean(SD): 4.07 (2.19) ms/mm Hg vs 10.23 (2.92) ms/mm Hg).

CONCLUSION

Baroreflex sensitivity can be assessed in term and preterm neonates by studying spontaneous variations in systolic blood pressure alone. This method could be useful for studying the ontogeny of baroreflex sensitivity and might therefore provide information about the maturation of the autonomic nervous system.

Balloon valvotomy for critical stenosis or atresia of pulmonary valve in newborns

OBJECTIVES

Percutaneous balloon valvotomy was studied retrospectively in newborns with critical pulmonary valve stenosis or atresia to assess its potential role as an alternative therapy to operation.

BACKGROUND

Severe right ventricular outflow tract obstructions are life-threatening conditions requiring prostaglandin infusion immediately after birth and then relief of the valvular obstruction. To avoid surgical hazards at this age, it would be useful to extend to newborns the balloon valvotomy so effective in older patients.

METHODS

Ninety-seven newborns (82 with critical pulmonary valve stenosis, 15 with atresia) underwent balloon valvotomy, provided that they had a well developed right ventricle, including an infundibulum close to the pulmonary artery. In patients with atresia, the outflow tract membrane had to be perforated with a wire needle or a radiofrequency probe.

RESULTS

Balloon valvotomy could be performed in 81 patients and was effective in 77. It caused 3 fatal and 16 nonfatal complications. Ten patients with persistent poor right ventricular compliance despite an effective valvotomy required a surgical shunt. Among the 81 patients in whom the procedure could be performed, right ventricular surgery was avoided in 5 (55%) of the 9 patients with atresia (95% confidence interval [CI] 28% to 80%) and 55 (76%) of the 72 patients with stenosis (95% CI 66% to 86%) at the end of the follow-up period (9.7 years).

CONCLUSIONS

Balloon pulmonary valvotomy is not always feasible in newborns, but it is relatively safe and effective and should be considered a valid alternative to operation.

[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.

[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)

[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)