[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.

Contribution of cardiac MRI in the comprehension of peripartum cardiomyopathy pathogenesis.

Pathogenesis of peripartum cardiomyopathy (PPC) is still discussed. We report one case of PPC in which a cardiac magnetic resonance imaging analysis allowed to exclude some "classical" pathogenesis hypotheses. We would like to emphasize the benefits of cardiac MRI in the comprehension of the mechanism(s) involved in the genesis of PPC.

Can peripartum cardiomyopathy be familial?

Peripartum cardiomyopathy (PPCM) is a rare disorder, with four principal features: 1--development of cardiac heart failure in the last month of pregnancy or within five months after delivery, 2--absence of an identifiable cause for heart failure, 3--absence of underlying heart disease prior to the last month of pregnancy, 4--evidence of left ventricular systolic dysfunction by classic echocardiographic criteria. Reported forms of familial peripartum cardiomyopathy are exceptional. Our observation emphasizes the interest of cardiac magnetic resonance imaging (MRI) in the investigation of an acute heart failure occurring during the peripartum and allows us to evoke a genetic predisposition in some cases of PPCM, to discuss the fact that some forms of familial PPCM could be unknown familial dilated cardiomyopathy unmasked by pregnancy, and to wonder on the familial screening modalities.

[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.

Long-term follow-up of percutaneous vena cava filters: a prospective study in 100 consecutive patients.

OBJECTIVES: the long-term outcome in following insertion of inferior vena cava (IVC) filters remains unclear. DESIGN: prospective study. MATERIAL AND METHODS: one hundred consecutive patients received percutaneous vena cava filters between 1988 and 1993. The patients underwent clinical examination, abdominal X-rays and duplex ultrasound of the IVC, right internal jugular vein and legs after a mean follow-up duration of 38+/-11 months. RESULTS: forty patients died after implantation (median 11.3 months; IQR: 1.8--20.4 months). The cause of death was known in 33 cases, and pulmonary embolism (PE) was suggested in three. Multivariate analysis revealed the mortality rate to be significantly higher in cancer patients (relative risk of 2.13). The 3-year survival was 20% for cancer patients and 71% for patients without cancer. Among the 60 living patients, thrombi were trapped in the filter in 10 cases, the filter tilted in four, was malpositioned in five and migrated in 29. These incidents were recorded as asymptomatic complications, as opposed to seven IVC thromboses and 23 recurrent lower limb thromboses, which were considered as symptomatic complications. CONCLUSION: long-term major complications are not frequent. As expected, cancer was the only factor predicting mortality. IVC filters seem effective in preventing PE.

Spontaneous closure of congenital coronary artery fistulas.

Six cases of full spontaneous closure of congenital coronary artery fistulas, and one case of near closure, as seen by colour Doppler echocardiography, are presented. It is worth reconsidering the classical view that nearly all cases of spontaneous closure are eligible for surgical or percutaneous correction to prevent the development of significant and potentially fatal complications. As the natural course of coronary artery fistulas is still poorly defined, asymptomatic patients, especially those under 7 years old with small shunts, should be periodically followed up by echocardiography rather than be subjected to operative closure, even by catheterisation.

[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.

Early prenatal management of a fetal ventricular tachycardia treated in utero by amiodarone with long term follow-up.

Fetal cardiac arrhythmias are one of the causes of intra-uterine congestive heart failure and non-immune hydrops fetalis leading to fetal death. As ventricular tachycardia (VT) is rarely diagnosed in utero, it leads to emergency deliveries. We report a prenatal diagnosis of fetal tachycardia at 20 weeks of gestation associated with non-immune hydrops fetalis. The tachycardia seemed to be supraventricular and was initially treated by digoxin and sotalol. The hydrops increased and sotalol was stopped in order to give the mother a high dose of amiodarone by mouth over a long period. Although the tachycardia, which the ECG recorded at birth revealed to be of ventricular origin, persisted but at a lower rate, the new treatment proved successful. The child is three years old now and health, though with persistent VT. In conclusion, fetal tachycardia with similar ventricular and atrial rates can be a VT and the drug of choice in this case seems to be amiodarone.

[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.

[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.

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.

[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.

[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.

[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.

[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.

[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.

Short-term follow-up of inferior vena caval filters: comparison of imaging techniques.

OBJECTIVE: The aim of this prospective study was to assess the advantages and limitations of various imaging techniques in identifying problems associated with percutaneous placement of filters in the inferior vena cava. SUBJECTS AND METHODS: One hundred four vena caval filters (65 Filcard, 39 Cardial) were placed in 100 patients (four patients received two filters). Venacavograms, duplex sonograms of the abdomen, abdominal radiographs, perfusion scans of the lung, and impedance plethysmograms were obtained in all patients within 1-2 days and 3 months after filter placement. CT scans of the filter were obtained in 55 patients. RESULTS: In five patients, thrombosis of the inferior vena cava, with retraction of the filter struts in four patients, was noted on venacavograms, CT scans, duplex sonograms, and impedance plethysmograms. Perforation of the inferior vena cava was noted in 36 patients after comparison of findings on venacavograms and CT scans, with an increase in the filter span in 29 patients (apparent on duplex sonograms in only two patients). Four filter tiltings (> 30 degrees) and 25 migrations (> 5 mm) were noted on abdominal radiographs. Trapped thrombi in the filter were shown on venacavograms in nine cases, but on duplex sonograms and unenhanced CT scans in only two cases. CONCLUSION: Our study shows that the major complications of inferior vena caval filters can be detected by noninvasive examinations. Only venacavograms consistently show small trapped thrombi that do not extend above the filter, but the importance of such thrombi is unknown.