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Résumé: Introduction: Le syndrome d’apnée obstructive du sommeil est incriminé dans l’aggravation et l’entretien de la maladie athéromateuse notamment coronarienne. Il reste cependant sous-diagnostiqué en milieu cardiologique. But: L’objectif de cette étude était de déterminer la prévalence du syndrome d’apnée obstructive du sommeil et les facteurs prédictifs de la forme sévère chez les patients hospitalisés pour un syndrome coronarien aigu avec sus-décalage persistant du segment ST. Patients et méthodes: Il s’agit d’une étude prospective portant sur 120 patients hospitalisés pour un syndrome coronarien aigu avec sus-décalage persistant du segment ST, entre avril 2011 et mars 2012. Tous les patients ont bénéficié d’un enregistrement polygraphique dans les 15 jours suivant l’infarctus. Le diagnostic de syndrome d’apnée du sommeil a été retenu en cas d’indexe apnée-hypopnée≥5 événements par heure ; la forme sévère a été définie par un indexe apnée-hypopnée≥30 événements par heure. Par ailleurs, une évaluation clinique de la qualité du sommeil a été réalisée par le score d’Epworth. Résultats: La population était constituée de 102 hommes et 18 femmes avec un âge moyen de 58±12ans. Les facteurs de risque cardiovasculaire étaient dominés par le tabagisme retrouvé dans 72 % des cas, 40 % des patients étaient diabétiques et 44 % étaient hypertendus. Quatre-vingt-sept pour cent des patients ont été pris en charge dans les 24 premières heures. Une angioplastie primaire a été pratiquée dans 60 % des cas et une fibrinolyse a été réalisée chez 10 % des patients. Un syndrome d’apnée obstructive du sommeil était présent chez 79 % de la population avec un indexe apnée-hypopnée moyen de 15,76±14,9. Une forme sévère de cette affection était identifiée chez 16 % des patients. Après analyse multivariée, les facteurs prédictifs indépendants de la forme sévère au décours d’un syndrome coronarien aigu avec sus-décalage du segment ST étaient un score d’Epworth≥ 4 et une désaturation nocturne≤82 % enregistrée par saturomètre au doigt à l’unité de soins intensifs cardiologiques. Conclusion: La prévalence du syndrome d’apnée obstructive du sommeil au décours d’un infarctus du myocarde était très élevée. Un score d’Epworth≥ 4 et une désaturation nocturne≤82 % étaient prédictifs de la forme sévère. [ABSTRACT FROM AUTHOR]

We present two numerical models for the study of unsteady two-dimensional flow of air subjected to a heat source in a cell divided into two areas of different size by a vertical lintel. The heat source placed on the floor of the enclosure produces hot gases for a finite time. First numerical model based on solving the equations of conservation of mass, momentum and energy, uses an implicit scheme in time and a finite difference hybrid space. The injection of hot gas in the two areas led to the abandonment of the Boussinesq hypothesis. This model also takes into account variations in the physical properties of the fluid. The second model is a finite element approach which gave more detailed results, thanks to the high density of the mesh node and the incorporation of the boundary conditions in the general equations of the problem. Dynamically, the results are very significant in terms of the flow direction, circulation areas and creation of vortices. The results for two simple cases of a cell partitioned allowed us to know the characteristics of the flow adjacent to the heat source and through the two compartments of the enclosure. [ABSTRACT FROM AUTHOR]

In this paper, an analytical method for the calculation of the electromagnetic field in the airgap of a permanent-magnet synchronous machine is developed, so as to compute the torque of the machine. Such a work is applicable to different machine topologies (even for salient rotor ones), when a two dimensional approximation of the structure is possible. This analytical model can be useful in an optimization task. In the first part, the analytical method of the field computation is explained in detail, both for the magnet's field, and for the armature reaction field. The results are compared to finite elements analysis. [ABSTRACT FROM AUTHOR]

The purpose of this study was to assess cardiac remodeling and to determine factors predicting the occurrence of atrial arrhythmia after surgical closure of atrial septal defect (ASD) in adults. Retrospective study including 33 adult patients (> 20 years old, mean age: 34 ± 11 years, 26 women) who underwent surgical closure of secundum or sinus venosus ASD. Before operation, all patients had dyspnea and 15% were in NYHA III-IV. Sinus rythm was present in 85% of patients. The ratio of pulmonary to systemic blood flow was calculated, yielding a mean of 2,8 ± 1 and pulmonary artery hypertension (PAH) was observed in 80% of patients with a mean value of 41,3 ± 10 mmHg. The ASD were closed by pericardial or Dacron patch in 97% of cases. Operative death was observed in 2 cases. In survival patient, with a follow-up of 97 ± 57 months, regression of right ventricular dilatation and PAH occurred in the first post-operative month and was maintained at late follow-up. Atrial arrhythmia occurred in 5 patients and were determined by older operative age (P = 0.003) and the absence of cardiac remodeling after surgery. Surgical correction of ASD in adults is safe and efficacious. Cardiac remodeling after ASD closure in the adult is a common and an early event and prevents late morbidity which is in most cases due to arrhythmias. The mode of closure does not seem to significantly impact remodeling. [ABSTRACT FROM AUTHOR]

Modifiable risk factors (RFs) play an important role in the development and prognosis of acute myocardial infarction (AMI). This study sought to study the prevalence rates of modifiable RFs during a first AMI, and sex differences in Tunisian young adults. This was a retrospective cohort analysis of a Tunisian tertiary center. From January 2014 to December 2020, we retrospectively studied data of patients with AMI younger than 45 years of age hospitalized for a first AMI. Prevalence rates of hypertension, diabetes mellitus, obesity, smoking, dyslipidemia, and drug abuse were analyzed in these patients. We enrolled 210 patients in the study. The prevalence of AMI in young patients was 8.5%. The mean age was 39.3 ± 4.9 years with a sex ratio of 11. The most frequent cardiovascular risk factors were smoking (88,6%) and dyslipidemia (32%) were the most prevalent risk factors (RF), and 98.6% of patients had at least 1 RF. Hypertension, diabetes, obesity, and drug abuse had a prevalence respectively of 30%, 28%, 8%, and 7.6%. Women had a higher prevalence of diabetes mellitus, hypertension, and obesity, and men had a higher prevalence of dyslipidemia, drug abuse, and smoking. During a first AMI in young adults in whom preventive measures are more likely to be effective, modifiable RFs were highly prevalent and progressively increased over time. Significant sex disparities were observed for individual RFs. [ABSTRACT FROM AUTHOR]

Hypertension is a common comorbidity of type 2 diabetes mellitus (T2DM). Both conditions are associated with an increased cardiovascular risk, which is reduced by tight blood pressure (BP) and glycemic control. However, non-dipping BP status continues to be an enduring cardiovascular risk factor in T2DM. This study aimed to investigate the association between microvascular complications of diabetes and nocturnal dipping of BP. We compared 13 type 2 diabetic patients with (DM+) and 67 diabetic patients without (DM−) manifest microvascular disease. BP dipping status was assessed from 24-hour ambulatory BP measurements. DM+ patients were older 60.3 ± 8.7 years vs. 58.3 ± 10.4 years (P = 0.47). There was no significant difference between the two groups in diabetes control, clinical systolic BP and clinical diastolic BP. Dyslipidemia was significantly more present in DM+, 84.7% vs. 47.8% (P = 0.015). DM+ patients had significantly higher daytime and 24-hour mean SBP than DM− patients with P = 0.02 and 0.023 respectively. Pulse pressure was significantly (P = 0.03) higher in DM+. The nocturnal blood pressure profile in DM+ was "non-dipper" and "reverse dipper" respectively in 69% and 15% of patients versus 27% and 11% in DM− (P = 0.003; P = 0.026). Our findings once again highlighted the importance of ambulatory BP monitoring and targeted antihypertensive therapy directed toward to restore normal circadian BP in patients with T2DM. [ABSTRACT FROM AUTHOR]

To determine whether the presence of calcium in the mitral valve commissures influences the immediate result of percutaneous mitral commissurotomy (PMC). PMC by the Inoue balloon was attempted in 247 patients (mean age: 35years) with severe MS. All the patients had undergone echocardiographic examination before PMC to assess mitral anatomy, commissural calcification (CC) and to determine the Wilkins score. According to the absence or presence of CC, patients were divided into 2 groups: 216 patients in group CC- (no commissural calcification) and 31 patients in group CC+ (presence of calcification in 1 or 2 commissures). Baseline mitral valve area (MVA) was 1 ± 0,19 cm2 (range 0,5–1,4 cm2), the mean value of Wilkins score was 7,98 ± 1,61(range 5–13) and 29 patients had unilateral commissural calcification. Post-PMC success was defined as final MVA ≥ 1,5 cm2 and no mitral regurgitation ≥ grade3. After PMC, the mean MVA increased to 1,79 ± 0,34 cm2 (P < 0,001) resulting in a success rate of 83%. Severe mitral regurgitation (MR) occured in 5 patients (2%). Final MVA (1,83 ± 0,32 cm2 versus 1,50 ± 0,36 cm2), success rate (87% versus 55%) and the rate of opening of at least one commissure (97% versus 77%) were significantly different between groups CC− and CC+ (P < 0,001). The rate of post-PMC MR of grade ≥ 3 was not different between the two groups (2% in group CC- and 0% in group CC+; P = 0,6) Our results showed that the presence of commissural calcification was associated with a lower procedural success rate but a good immediate result could be achieved in half of cases. Then, unilateral commissural calcification should not be considered as a contra-indication to PMC. [ABSTRACT FROM AUTHOR]