[Long QT syndrome: an underestimated cause of sudden infant death]. / Le syndrome du QT long congénital : une cause sous-estimée de la mort subite inexpliquée du nourrisson.

Congenital long QT syndrome (LQTS) is an inherited arrhythmia that can be sporadic or familial. It predisposes to sudden cardiac death by ventricular fibrillation, which can occur at any age, particularly in neonates. Recent postmortem molecular screening surveys have shown that 10 to 12% of sudden infant death syndrome (SIDS) cases were potentially related to congenital long QT syndrome. Current SIDS etiological surveys fail to diagnose LQTS. Specific questioning and electrocardiographic screening of first-degree relatives could greatly facilitate LQTS diagnosis. We propose adding these to screening modalities after a SIDS incident. Neonatal electrocardiographic screening could allow early identification of LQTS and adapted treatment and follow-up.

Multisensor fusion for atrial and ventricular activity detection in coronary care monitoring.

Information management for critical care monitoring is still a very difficult task. Medical staff is often overwhelmed by the amount of data provided by the increased number of specific monitoring devices and instrumentation, and the lack of an effective automated system. Specifically, a basic task such as arrhythmia detection still produce an important amount of undesirable alarms, due in part to the mechanistic approach of current monitoring systems. In this work, multisensor and multisource data fusion schemes to improve atrial and ventricular activity detection in critical care environments are presented. Applications of these schemes are quantitatively evaluated and compared with current methods, showing the potential advantages of data fusion techniques for event detection in noise corrupted signals.

[Pregnancy and anticoagulant therapy. Indications and strategies]. / Grossesse et traitement anticoagulant. Indications et modalités.

Anticoagulant therapy is sometimes required during pregnancy either for the prevention of thromboembolic disease, for patients already on long-term antithrombotic treatment (for valvular prostheses) or for the prevention of complications of risk factors such as hereditary or acquired thrombophilia. Pregnancy is in itself a hyper-coagulable condition and the risk of thromboembolic complications is raised. Anticoagulation is a risk to the mother and to the foetus, and the management (heparin or vitamin K antagonists, respective doses) must be adapted to the underlying pathology and the stage of pregnancy. Mechanical valve prostheses are the most difficult problem and different strategies are proposed. The use of low molecular weight heparin may improve the outcome of these patients, but further trials are necessary.

[Heparin therapy in pregnant women]. / Traitement par héparine chez la femme enceinte.

The prescription of heparin during pregnancy is an uncommon situation but a difficult one to manage because there are no reported therapeutic trials. The main indications are thromboembolic disease, valvular or congenital heart disease, cardiac arrhythmias and patients at high risk of thrombosis with blood clotting disorders. Non-fractionated heparin is the commonest form of anticoagulation in these circumstances as it does not cross the placental barrier; there are no teratogenic or haemorrhagic risks to the foetus. However, its dosage is difficult in pregnant women and this may lead to complications such as haemorrhage, heparin-induced thrombocytopaenia and osteoporosis; in addition, the duration of the treatment is often long and it can affect tolerance. Low molecular weight heparins are a promising alternative because of their long half-lives which give a more predictable dose-effect and reduce the number of daily injections. The risk of heparin-induced thrombocytopaenia is lower. At present, their legal prescription is limited to enoxaparin during the 2nd and 3rd terms of pregnancy as prophylactic treatment. The recommendations described in this article are the result of the 6th Consensus of the ACCP on antithrombotic treatment, which cautions the use of low molecular weight heparin during pregnancy. Different therapeutic regimes are presented according to the degree of thromboembolic risk. In patients with mechanical valvular prostheses, the recommendations are variable, with many workers, especially European groups, preferring anticoagulation to heparin from the 12th to the 36th week of pregnancy because of the greater efficacy of this particular indication. Peridural anaesthesia may be carried out with heparin therapy providing the level of anticoagulation is monitored and the procedure is performed under well controlled conditions. In cases presenting formal contra-indications to heparin therapy, heparinoids may be used instead. In future, low molecular weight heparin therapy will probably play a larger role in anticoagulation during pregnancy and in all the potential therapeutic indications.

[Permanent junctional reciprocating tachycardia in children and adolescents. Efficacy of medical treatment]. / Les tachycardies jonctionnelles permanentes par rythme réciproque chez l'enfant et l'adolescent. Efficacité du traitement médicamenteux.

Between 1969 and 1991, 11 patients were followed up for permanent junctional reciprocating tachycardia. The average age at diagnosis was 2 years and 4 months (1 day to 14 years). The tachycardia was diagnosed at routine examination in 5 cases and following an episode of cardiac failure in the other 6. Digitalis was prescribed in all patients with 4 good results, 5 average and 2 poor results. One patient, who remained in mild cardiac failure with digitalis therapy, died suddenly at the age of 9 years. In more recent cases, amiodarone was used from the onset or secondarily with good results in all patients. In 2 patients, in whom amiodarone was withdrawn after 3 months and 3 years' treatment, there was a recurrence of the tachycardia. No side effects of amiodarone therapy were observed in this series. Three patients were prescribed flecainide with 1 good and 2 average results. Propranolol, used in 2 cases, was associated with 1 average and 1 poor result. Disopyramide and Verapamil were ineffective. These results suggest that amiodarone is the drug to choose in permanent junctional reciprocating tachycardia but it must be given long term. The persistence of cardiac failure, poor control of the tachycardia or secondary effects of drug therapy should lead to consideration of non-medical management of the tachycardia.

[Influence of age and body surface on the signal averaged high amplification ECG after complete repair of tetralogy of Fallot]. / Influence de l'âge et de la surface corporelle sur le signal moyenné de l'ECG haute amplification après réparation complète des tétralogies de Fallot.

The aim of this study was to assess the influence of age and body surface area on the signal averaged ECG after complete repair of Tetralogy of Fallot. Fifty eight patients operated for Tetralogy of Fallot in whom the postoperative ECG showed right bundle branch block without any significant arrhythmia on Holter monitoring or exercise stress testing underwent signal averaged electrocardiography. A very significant relationship was observed between age and body surface area and the duration of the filtered QRS (r = 0.45, p = 0.0004 and r = 0.49, p = 0.00009 respectively) or the average voltage of the last 40 milliseconds (r = -0.49, p less than 0.03 and r = -0.31, p less than 0.02 respectively). Therefore, signal averaged ECG in patients operated for Tetralogy of Fallot varies with age and morphology. An adjustment of the parameters of the signal averaged ECG with respect to clinical characteristics is necessary before assessing the value of this technique for identifying patients at risk of developing ventricular arrhythmias.

[Left intraventricular dynamic gradients in the follow-up of aortic valve replacement: an echo-Doppler study]. / Gradients dynamiques intraventriculaires gauches dans les suites de remplacement valvulaire aortique: étude écho-Doppler.

The possibility of an intraventricular pressure gradient in patients with aortic stenosis is well known: this entity is associated with a high risk of postoperative complications. The authors carried out a Doppler echocardiographic study of flow in the left ventricle in 51 patients who had recently undergone valve replacement for severe aortic stenosis (valve area < 0.75 cm2). Before surgery, only one patient had significant acceleration of intraventricular systolic flow attaining 3.8 m/s (maximum pressure gradient of 60 mmHg). After surgery, maximum intraventricular systolic velocities of over 2.5 m/s with a typical end systolic peak were observed in 8 patients under basal conditions (gradients of 30 to 115 mmHg), and in 7 others after inhalation of amyl nitrite. Pulsed spectral and color Doppler flow mapping showed that the highest velocities were located at the mitral papillary muscle level. In addition, these patients had significant reduction in cavity size. Only one patient had systolic anterior motion of the anterior mitral leaflet with septal contact. Left ventricular dimensions were measured by TM echocardiography. High intraventricular velocities seemed to be significantly related to the smallest ventricular dimensions, the thickest ventricular walls and the smallest preoperative aortic valve surface area. The highest intraventricular pressure gradients-disappeared with betablocker therapy (4 cases), after correction of hypovolemia (1 case), after drainage of large pericardial effusions (2 cases) or spontaneously (1 case). This study confirms the relatively high prevalence of dynamic intraventricular gradients after surgical cure of aortic stenosis and the value of Doppler echocardiography for the avoidance of certain drugs (inotropic agents, vasodilators, diuretics), which could aggravate the hemodynamic abnormality.(ABSTRACT TRUNCATED AT 250 WORDS)

[Dilatation of critical aortic value stenosis in infants under 3 months of age. Our experience from 15 cases]. / Dilatation des sténoses valvulaires aortiques critiques chez le nourrisson âgé de moins de 3 mois. Expérience à partir de 15 cas.

Between April 1988 and October 1992, 15 consecutive infants aged less than 3 months (average 17 days) with critical valvular stenosis underwent balloon dilatation. Thirteen were less than 1 month old and all had low output syndromes. The diagnosis and follow-up assessments were made by Doppler echocardiography. Before valvuloplasty the maximum instantaneous gradient was 75 +/- 34 mmHg. The average diameter of the aortic ring was 6.8 +/- 1.3 mm. Seven patients had aortic rings with diameters of less than 7 mm. Ten infants had a right-to-left shunt via a patent ductus arteriosus and pulmonary hypertension. Dilatation was performed after surgical denudation of the left carotid artery: a balloon catheter with a diameter 0.85 times that of the aortic ring was used. After dilatation, the gradient was 26 +/- 18 mmHg (p < 0.001). Grade I aortic regurgitation was observed in 4 cases and Grade II in 2 cases. Eight patients died 1 to 100 days after dilatation (seven of low output and one sudden death). Of these patients, 6 had aortic rings < 7 mm diameter. The average follow-up was 20.6 +/- 15.5 months (range 2 to 48 months). None of the patients had a precordial or carotid diastolic murmur. The gradient increased with improvement in left ventricular function. Two patients had a stable Grade I aortic regurgitation. Carotid Doppler echocardiographic control examinations performed in 4 patients were normal. Poor prognostic factors were: aortic ring diameter < 7 mm (p < 0.025) and a low gradient after dilatation (p < 0.012).(ABSTRACT TRUNCATED AT 250 WORDS)

[Indications of partial interruption of the inferior vena cava in pulmonary embolism]. / Indications d'interruption partielle de la veine cave inférieure dans l'embolie pulmonaire.

Forty years after the first implantation of caval filters, there is still no indication for implantation validated by a controlled clinical trial. This fact may be explained by our poor understanding of the evolution of thromboembolic disease, especially in certain groups of patients. The absolute contra-indications to heparin therapy would seem to be a logical indication for a caval filter. In cases of a relative contra-indication to anticoagulants, the physician has to rely on his clinical judgement and the decision will be taken case by case. In patients with suspected pulmonary embolism under anticoagulant therapy, it is also logical to check that anticoagulation is effective, and to request proof of embolism, to assess its risk and that due to thrombosis before considering a caval filter. The prophylactic implantation of a caval filter is a very controversial indication whether the thrombus is proximal in the ilio-caval region, extensive, not uncommon despite treatment, or floating. For groups said to be at high risk of thromboembolism (elderly, malignant disease or multiple injuries), there is no consensus because of the discordant results in the literature. The implantation of a filter would seem to be justified in patients with chronic cor pulmonale after pulmonary embolectomy. The value of a temporary caval filter during thrombolysis has not been demonstrated; there are hopes that temporary filters "of long duration" will provide filtration of the vena cava during vulnerable periods. The results of the first controlled trial (PREPIC) are eagerly awaited and should rationalise the indications of inferior vena cava filters.

[Right atrial compressive aneurysm with favorable outcome after surgery at the age of 1 month]. / Anévrisme compressif de l'oreillette droite d'évolution favorable après traitement chirurgical à 1 mois de vie.

Right atrial aneurysms are uncommon and often revealed by arrhythmia. We report a case of right atrial aneurysm which required an early management and its follow up during one year. The abnormality was detected at 32 weeks gravida during a systematic echography. At birth the newborn was asymptomatic but with the progressive increase of the aneurysm size shifting the heart and vessels and the occurrence of an intra-cardiac thrombus, a surgical management was decided at the age of one month. The resection of the aneurysm was therefore performed and no complication occurred during recovery. After one year the child remains healthy. The surgical indications are difficult to precise as the majority of these aneurysms are detected at an adult age. Surgical management appears to be essential in case of poor tolerance. The prognosis after surgery seems favorable.

[Platypnoea-orthodeoxia syndrome. Diagnosis, etiology, treatment]. / Syndrome de platypnée-orthodéoxie. Diagnostic, étiologie, traitement.

Platypnoea-orthodeoxia (P.O.) syndrome is the association of dyspnoea and arterial oxygen desaturation aggravated in the erect position and relieved in the supine position. Initially considered very rare (20 cases reported over fifty years) and occurring essentially in patients having undergone pneumonectomy, it in fact occurs much more frequently if only it is looked for (20 extra cases reported in a single year). Some new aetiologies have been described, in particular dilatations or aneurysms of the ascending aorta. Diagnosis is made easier if the oxygen saturation is measured in the supine position when it is normal, and in the erect position when it falls considerably. Another argument is added by the small effect of inspiration of high concentrations of oxygen. Contrast echocardiography confirms the right-left shunt and allows estimation of the site. This is usually situated at the atrial level, via an inter-atrial communication or more often a patent foramen ovale; as a rule the area of dehiscence having been modified by the associated pathology allowing the right-left shunt despite normal right pressures. Exceptionally the shunt is situated at the vascular or pulmonary parenchymal level. Poor tolerance of P.O. syndrome justifies a therapeutic procedure; this is usually closure of the septal fault with an occluder introduced percutaneously; the results are generally highly spectacular.

[Comparison of apical and infundabular pacing in patients with primary dilated or ischemic cardiomyopathy]. / Comparaison de la stimulation apicale et infundibulaire chez les patients atteints d'une cardiomyopathie dilatée primitive ou ischémique.

Dual chamber pacing has been proposed as an alternative treatment to patients with cardiac failure refractory to optimal medical therapy. The influence of the site of ventricular pacing was studied in 15 patients with an average age of 68.7 +/- 8.7 years with dilated cardiomyopathies and an average left ventricular ejection fraction of 22.3 +/- 6.8%. Three temporary USCI electrodes were positioned in the right atrium, the right ventricular outflow tract (RVOT) and the right ventricular apex. The average duration of the QRS complexes and the haemodynamic parameters (PAP, PCP and cardiac index) were measured in sinus rhythm and during DDD apical, RVOT and simultaneous apical and RVOT pacing. The RVOT and simultaneous pacing significantly reduced the QRS duration (135 +/- 14 ms and 137 +/- 17 ms, p < 0.0001 respectively) compared with apical pacing (150 +/- 19 ms). The mean PAP and mean PCP remained unchanged in the different modes of pacing but the cardiac index increased significantly during RVOT pacing (2.99 +/- 0.67 l/min/m2) and simultaneous pacing (3 +/- 0.77 l/min/m2) compared with apical pacing (2.66 +/- 0.62 l/min/m2) (p < 0.001 and p < 0.01 respectively) and compared with sinus rhythm (2.62 +/- 0.7 l/min/m2) (p < 0.001 and p < 0.005 respectively). This study suggests that better results may be obtained with RVOT screw in lead than with the traditional right ventricular apical electrode.

[Right atrial thrombosis and severe pulmonary embolism]. / Thrombose auriculaire droite et embolie pulmonaire grave.

Two cases of severe pulmonary embolism associated with right atrial thrombosis are reported. In the first case, fibrinolytic therapy was administered and was thought to be a causative factor in the death of the patient due to massive pulmonary embolism. In the second case, the patient was referred for surgery and two enormous thrombi were extracted. Unfortunately, the outcome was fatal. These two cases were confronted with the results of the literature. They strongly suggest that echocardiography should be a first-line investigation in severe pulmonary embolism. The detection of right atrial thrombosis modifies the clinical strategy and orientates treatment towards surgical referral when the patient's condition allows it.

[Efficacy and tolerance of 2 new percutaneous vena cava filters. A prospective study in 80 patients]. / Efficacité et tolérance de deux nouveaux filtres cave percutanés. Etude prospective chez 80 patients.

Eighty consecutive patients with an average age of 66.5 +/- 16 years were reviewed 3 and 9 months after implantation of two new percutaneous vena caval filters (Filcard, Cardial) in order to evaluate their efficacy and tolerance. The indications were: a contra-indication to anticoagulants in 19 cases, recurrent pulmonary embolism under anticoagulant therapy in 22 patients, chronic cor pulmonale in 4 patients; finally, in 35 cases, the filter was implanted prophylactically for a "floating" or extensive ilio-caval thrombosis under anticoagulant therapy or in high risk patients: severe cardio-pulmonary failure, malignant disease, massive pulmonary embolism with a contra-indication to fibrinolytic therapy. All implantations were performed by the jugular approach with no local or general complications apart from one pericaval haematoma with a favourable outcome. Cavography and opacification of the renal veins was carried out systematically during implantation. All patients underwent clinical examination, antero-posterior and lateral X rays of the filter, pulmonary scintigraphy, antero-posterior and lateral cavography, a CT scan of the filter, Doppler ultrasonography and rheoplethysmography of the legs 3 months after implantation. At 9 months, clinical examination, abdominal X rays and rheoplethysmography were repeated. There was 100% follow-up at 3 and 9 months. The complications observed at 3 and 9 months were: 5 cases of malposition (6%), 3 recurrent pulmonary emboli (4%), 9 recurrent venous thromboses (13%), 4 vena caval thromboses (5.7%), 7 thrombi caught in the filter (10%), 27 perforations of the vena cava (38%), 3 over 30 degrees tilts of the filter (4%) and 22 migrations (31%).(ABSTRACT TRUNCATED AT 250 WORDS)

[Stenosis of the branches of the pulmonary artery caused by Hodgkin's lymphadenopathies]. / Sténoses des branches de l'artère pulmonaire par des adénopathies hodgkiniennes.

A 22 year old patient was admitted to hospital for dyspnoea and haemoptysis. Cardiac catheterisation showed a pressure gradient between the main pulmonary artery and its branches. Pulmonary angiography showed appearances of extrinsic compression of the branches of the pulmonary artery. This was shown to be caused by lymphadenopathy on CT scan and Hodgkin's disease was diagnosed after surgical biopsy. The pressure gradient between the main pulmonary artery and its distal branches almost completely regressed after chemotherapy and radiotherapy.

[Long-term follow-up of a rare complication of vena cava filters: complete and spontaneous rupture of the filter]. / Suivi a long terme d'une complication rare des filtres cave: la rupture complète et spontanée du filtre.

Complete spontaneous rupture of a percutaneous caval filter produced two equal parts. Long-term follow-up showed that the filter then remained stable with no complications. This case emphasizes the importance of long-term follow-up of patients with caval filters.

[Fetal echocardiography]. / L'échocardiographie foetale.

Cardiac malformations are the most frequent and serious fetal malformations. However their prenatal diagnosis is the less easy. Fetal echocardiography is the main diagnostic tool; in addition it is helpful for the therapeutic orientation. Only 30% of fetal heart diseases are detected on account of maternal or fetal indications, most of them being discovered without any known risk factor. In order to improve its diagnostic sensitivity, fetal echocardiography must include a four chambers view and a study of ventricular and arterial connection. Nevertheless, many heart diseases remain undetected, most of them being minor with favorable prognosis. Search of an extracardiac abnormality and karyotype analysis must be performed in order to explicit the prognosis. Fetal arrhythmias can be analyzed by study of the atrial and ventricular contraction using M-mode echocardiogram or Doppler mode; most of them are supraventricular and accessible to maternal therapy. The sustained fetal bradycardia is frequently a complete heart block whose prognosis depends upon its association with a heart defect and/or a ventricular escape. Antibodies SS-A and SS-B are frequently associated with complete heart block without structural heart defects. Hypertrophic cardiomyopathy may be observed in fetus of diabetic mothers needing an accurate evaluation of the thickness of the interventricular septum. Echocardiography is a part of fetal medicine, which includes the different specialties devoted to the fetus.

[Preoperative mortality in transposition of the great vessels]. / Mortalité préopératoire de la transposition isolée des gros vaisseaux.

UNLABELLED: 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.

[Doppler echocardiography in the evaluation of volume expansion effects in newborn infants]. / Apport de l'échocardiographie-doppler dans l'évaluation des effets de l'expansion volémique chez le nouveau-né.

BACKGROUND: The effects of volume expansion on the cardiac output (CO) of newborns have not been studied, so that the indications for colloid infusion are not well standardized. POPULATION AND METHODS: Twenty one newborns (14 preterm and seven term babies) were studied before the 7th day of life. Thirteen had patent ductus arteriosus (PDA) and six had ischemic cardiopathy. Hemodynamic data indicated that these babies should be given 20 ml/kg of a 10% albumin solution. Pulsed-wave Doppler echocardiography was performed before and after infusion. RESULTS: Only 11 newborns had initial low Co (less than 260 ml/kg/min in patients with PDA; less than 200 ml/kg/min in the others). The increases in CO (31 +/- 25% vs 7 +/- 11%, P < 0.01) and of mean aortic flow velocity (MAFV) (34.6 +/- 19.5% vs 7.2 +/- 6.1%, P < 0.01) were significantly greater in this group. The increases in mean arterial pressure (+4 +/- 5 mmHg) and CO (+20 +/- 18%) were significant (P < 0.01) for all patients, both premature and term (with or without PDA and ischemic cardiopathy). The increase in CO was correlated with the initial CO and the cutaneous refilling time but was not correlated with the increase in arterial pressure. The sizes of the ventricles and left atrium grew significantly but that of the right atrium did not. Analysis of the increase in stroke volume in terms of the end diastolic diameter of the left ventricle indicated that the cardiac reserves varied according to the Starling relation. CONCLUSION: Evaluation of MAFV and CO plus diagnosis of PDA are all needed in order to assess whether volume expansion is accurate or not, since, clinical data obtained during the neonatal period are insufficient to do this.