Postprandial duodenojejunal motility in health and idiopathic severe gastroparesis: from conventional analysis to nonlinear dynamics analysis.

Our aim was to compare the results of the analysis of postprandial duodenojejunal motor patterns provided by a conventional computer-aided analysis with those provided by the new nonlinear mathematical method borrowed from 'chaos theory for determining how nonlinear analysis can improve fed motor pattern analysis and detect organization of postprandial contractions. Ten patients who had been explored for an idiopathic gastroparesis, and 20 healthy volunteers underwent duodenojejunal manometric recording for 3 h after a 750 kcal meal. Computer-aided analysis on each half-hour of the postprandial recording period calculated the number of waves (NW) and the area under the curve (AUC). Pressure signals were concurrently described by phase portraits obtained by plotting each pressure value at time t with the pressure value at time t + 1 s. The shape and amplitude of phase portraits were visually analysed and the relative area covered (RAC) by the phase portraits was calculated. With conventional analysis, NW and AUC were maximal during the first post-meal hour then decreased with time both in healthy volunteers and gastroparetic patients. With this analysis, the only difference between patients and controls was a lower NW (P < 0.02) in patients, observed only in the duodenum. Phase portraits analysis demonstrated lower RAC, a different distribution of RAC and more regular phase portraits in patients than in controls. Phase portraits outlined the heterogeneity of the patient group contrasting with the homogeneity of the control group when no subgroup was demonstrated by conventional analysis. We therefore conclude that the study of post prandial duodenojejunal motor behaviour could be improved by nonlinear dynamic analysis.

Hypothesis: hyperstructures regulate bacterial structure and the cell cycle.

A myriad different constituents or elements (genes, proteins, lipids, ions, small molecules etc.) participate in numerous physico-chemical processes to create bacteria that can adapt to their environments to survive, grow and, via the cell cycle, reproduce. We explore the possibility that it is too difficult to explain cell cycle progression in terms of these elements and that an intermediate level of explanation is needed. This level is that of hyperstructures. A hyperstructure is large, has usually one particular function, and contains many elements. Non-equilibrium, or even dissipative, hyperstructures that, for example, assemble to transport and metabolize nutrients may comprise membrane domains of transporters plus cytoplasmic metabolons plus the genes that encode the hyperstructure's enzymes. The processes involved in the putative formation of hyperstructures include: metabolite-induced changes to protein affinities that result in metabolon formation, lipid-organizing forces that result in lateral and transverse asymmetries, post-translational modifications, equilibration of water structures that may alter distributions of other molecules, transertion, ion currents, emission of electromagnetic radiation and long range mechanical vibrations. Equilibrium hyperstructures may also exist such as topological arrays of DNA in the form of cholesteric liquid crystals. We present here the beginning of a picture of the bacterial cell in which hyperstructures form to maximize efficiency and in which the properties of hyperstructures drive the cell cycle.

Internal right atrial cardioversion of chronic atrial fibrillation: effects of low-energy biphasic shocks.

This study evaluates the efficacy and safety of internal right atrial cardioversion of atrial fibrillation using a defibrillation right atrial catheter and 2 thoracic patches with low-energy biphasic shocks.

[Spontaneous ventilation in positive expiratory pressure in cardiogenic pulmonary edema. Prospective study]. / Ventilation spontanée en pression expiratoire positive au cours de l'oedème pulmonaire cardiogénique. Etude prospective.

New equipment facilitating the use of spontaneous ventilation with positive expiratory pressure (PEP) has become available in France since January 1996. This technique was applied in 38 patients with severe cardiogenic pulmonary oedema and persistent respiratory distress despite high flow classical oxygen therapy and standard treatment. After 1 hour of ventilation with a flow of 220 l/min of 100% oxygen with an average PEP of 7.7 cm H20, a significant improvement of clinical (heart and respiratory rate) and biological parameters (arterial gases) was observed. There were no side effects. Four patients died during the hospital period and only 1 was intubated. Spontaneous ventilation with PEP is a simple technique for coronary care units and, compared with conventional oxygen therapy, it rapidly improves arterial oxygenation, reduces respiratory work and improves conditions of cardiac load. Acute severe cardiogenic pulmonary oedema seems to be an indication of choice, especially in the elderly, where it may help avoid an often controversial intubation.

Safety of high energy internal cardioversion for atrial fibrillation.

High energy internal cardioversion has been proposed as an alternative method to cardiovert drug refractory or external cardioversion refractory atrial fibrillation. However, the safety of this technique has not been clearly evaluated. We reviewed findings in 53 patients who underwent 55 sessions of high energy internal cardioversion (2 patients underwent 2 sessions) for termination of longstanding atrial fibrillation. Shocks energy varied from 70-270 J. Three patients had 3 shocks during the same session, 5 had 2, and 47 only 1. Success rate was 89% (success was defined as immediate conversion to normal sinus rhythm). Low cardiac output occurred in two patients, and resulted in the death of one of these individuals, a patient with significant hypertrophic cardiomyopathy and heart failure. The other patient recovered completely. In 11% of the cases, shock induced transient atrioventricular block, necessitating ventricular pacing until sinus rhythm was restored. In three patients, a moderate but asymptomatic and uncomplicated pericardial effusion was diagnosed on echocardiogram. Finally, four patients had side effects related to venous puncture, which resolved spontaneously. These results suggest that high energy internal cardioversion is effective for conversion of atrial fibrillation. However, the technique may not be optimal in patients with advanced hypertrophic cardiomyopathy and in such cases the technique should be used carefully and only in the case of failure of external cardioversion; no more than two shocks should be delivered during the same procedure. Temporary ventricular pacing should be provided in all patients and an echocardiogram should be performed before patients are being discharged.

Long-term prognosis in patients with alcoholic cardiomyopathy and severe heart failure after total abstinence.

We prospectively evaluated the long-term prognosis of 14 patients with alcoholic cardiomyopathy and severe end-stage congestive heart failure after total abstinence. Improvement was very significant after 6 months of follow-up in most patients, and continued thereafter.

[Angiographic course over 10 years of giant aneurysm of the circumflex artery]. / Evolution angiographique sur 10 ans d'un anévrisme géant de la circonflexe.

Pathological dilatations of the coronary arteries are not exceptional and are called megadolichoartery, aneurysm or ectasia. Cases of marked arterial dilatation, although much rarer, are regularly reported following their discovery due to the impressive angiographic, echocardiographic or autopsy findings. However, their course, particularly in the long term, remains unclear. The authors report the case of a patient with a very large spindle-shaped aneurysm of the circumflex artery whose course was able to be followed over a period of ten years on three successive angiographic assessments performed for clinical coronary events. This follow-up was dominated by thrombosis of the aneurysm, extension of the aneurysmal disease and severe deterioration of left ventricular function.

[Internal atrial defibrillation after failure of attempted pharmacological and electrical cardioversion. Mid- and long-term outcome]. / Défibrillation auriculaire par voie interne après échecs des tentatives de réductions pharmacologiques et électriques par voie externe. Résultats à moyen et long terme.

Cardioversion of atrial fibrillation by an endocavitary electrical shock was first proposed during the 1980s. The authors studied the efficacy of this technique at short and medium term in a population of 36 patients (28 men and 8 women) in whom atrial fibrillation persisted despite attempts to reduce it by antiarrhythmic drugs and external electrical cardioversion. The immediate success rate was high : 34 out of 36 patients (94%) and, at medium term, the number with sinus rhythm was comparable to that of studies evaluating the medium-term efficacy of external electrical cardioversion; 19 out of 33 patients (57%) were in sinus rhythm at 6 months and 9 out of 27 patients (33%) at 12 months. These results seem to justify attempts at internal atrial defibrillation in patients in whom the other two techniques of cardioversion have failed. Its use as the method of first intention could be proposed if the profile of "resistant" patients to classical techniques was known, which is unfortunately not presently the case.

[Mortality and morbidity in the acute phase of myocardial infarction. Comparison of 3 patient cohorts admitted to hospital over 10 years]. / Mortalité et morbidité à la phase aiguë de l'infarctus du myocarde. Comparaison de trois cohortes de patients hospitalisés espacées de 10 ans.

The management of acute myocardial infarction has been transformed over the last thirty years by a number of therapeutic innovations. The authors decide to compare the outcomes of three cohorts of unselected patients admitted to hospital at 10 year intervals, to evaluate the impact of these innovations on morbidity and mortality. Six hundred and sixty one patient admitted to the Coronary Care Unit for acute myocardial infarction were included: Group I comprised 223 patients admitted consecutively during the period 1972-1973; Group II comprised 243 patients admitted between 1982-1983 and Group III comprised 195 patients admitted between 1992-1993. The average age was comparable, about 65 years, in the 3 groups, although there were gender differences. Taking into consideration earlier hospital admission, the in-hospital mortality decreased from 25% in Group I to 21.8% in Group II and to 15.4% in Group III (p < 0.05 between the first 2 groups and the third group). This decrease in mortality is even greater in anterior wall infarction and is observed in all ages. Similarly to selected patients in large scale randomised clinical trials, the ordinary "run of the mill" patient has also benefited from therapeutic innovations over the last ten years.

Accuracy and mean duration of different protocols of head-up tilt testing.

Based on the results of our study, > 95% of patients with a positive passive tilt test are also positive during 3 micrograms/min, and especially 5 micrograms/min, isoproterenol tilt test. A proposed time-saving protocol would be to initiate the test with an isoproterenol infusion and to perform a 45-minute passive tilt only in those patients with a positive 5 micrograms/min (an infusion rate reported to have an excessive low specificity) isoproterenol tilt test, and to consider only those with symptoms associated with objective changes during this latter test as "finally positive." An alternative option would be to perform a 45-minute passive tilt only in those patients with a negative 3 micrograms/min isoproterenol tilt test.

[Contribution of doppler echocardiography to the diagnosis of the first attack of acute rheumatic fever]. / Apport de l'échographie-doppler cardiaque au diagnostic de la première poussée de rhumatisme articulaire aigu.

Since 1944, the Jones criteria for the diagnosis of acute rheumatic fever have been regularly revised to integrate technical and diagnostic innovations. Echographic and Doppler criteria, however, remain unrecognised due to valvular insufficiency in healthy subjects. The aim of this study was to determine the cardiac lesions occurring in acute rheumatic fever and the diagnostic value of Doppler echocardiography. One hundred patients with an average age of 10 years were admitted to hospital because of a first attack of acute rheumatic fever between January 1991 and September 1992. Eighty-six had articular signs, 5 had chorea, but none had cutaneous lesions. Forty-seven murmurs of mitral insufficiency (MI) and eight of aortic insufficiency (AI) were detected; 10 children had signs of cardiac failure. Conduction defects were recorded in 12 cases. Echocardiography showed 7 pericardial effusions; often, the left heart chambers were dilated without alteration of the fractional shortening. The commonest lesions of the mitral valve were thickening of the two leaflets, the reduced mobility of the posterior leaflet, the rigidity of the anterior leaflet and 2 cases of ruptured chordae tendinae. The Doppler mode showed 73 cases of MI, 26 of which were at least moderately severe. These cases of MI were commonly excentric jets behind the posterior leaflet. There were 47 cases of AI, 10 of which were at least moderately severe. If all cases of moderately severe or mild AI and MI are considered as pathological when associated with suggestive morphological valve changes, the number of cases of carditis increased from 50 without the Doppler mode to over 80 with this mode. Doppler echocardiography validated the Jones criteria in 16 children. The authors propose Doppler echocardiography criteria for the validation of carditis.

Unstable periodic orbits and templates of the Rossler system: Toward a systematic topological characterization.

The Rossler system has been exhaustively studied for parameter values (a in [0.33,0.557],b=2,c=4). Periodic orbits have been systematically extracted from Poincare maps and the following problems have been addressed: (i) all low order periodic orbits are extracted, (ii) encoding of periodic orbits by symbolic dynamics (from 2 letters up to 11 letters) is achieved, (iii) some rules of growth and of pruning of the periodic orbits population are obtained, and (iv) the templates of the attractors are elaborated to characterize the attractors topology. (c) 1995 American Institute of Physics.

[Rupture and extravascular migration of a vena cava filter. Apropos of a case]. / Rupture et migration d'un filtre cave en dehors du vaisseau. A propos d'un cas.

The authors report the case of a 68 year old woman who underwent implantation of a Greenfield vena caval filter for recurrent pulmonary embolism. Migration of the filter out of the vena cava into the perivenal fat was discovered two years later during another embolic episode. One of the spokes of the filter had migrated into the iliac fossa. This case illustrates two possible complications of caval filters: rupture and migration. The increasing number of cases reported in the literature indicates the necessity of keeping a register of the complications encountered with different models to avoid the most dangerous ones.

Computations of the g(n) coefficients in the generalized Lorenz-Mie theory using three different methods.

Three different methods can be used to numerically compute the g(n) coefficients in the generalized Lorenz-Mie theory. Two of them are rigorous and involve (i) numerical evaluation of quadratures and (ii) numerical evaluation of finite series. The third way relies on the so-called localized interpretation that we discussed in previous papers. These three methods are discussed and compared.