Strain effects on the electronic, optical and electrical properties of Cu2ZnSnS4: DFT study.

Based on the density functional theory and Boltzmann transport theory, we investigated electronic, electrical and optical properties of Kesterite CZTS under different strain conditions. Our results indicate that both biaxial compressive and tensile strain effects lead to change in the band gap of this structure with different strain values. Furthermore, the edge of absorption, under the influence of an increasing compression, moves towards the short wavelengths. Electrical conductivity for pure CZTS and under dilatation and compression shows that with the increase of dilatation the conductivity of the material also increases, this physical property could be exploited to improve the performance of CZTS a suitable absorbent material in solar cells.

Impact of obstructive sleep apnea in recruitment of coronary collaterality during inaugural acute myocardial infarction.

BACKGROUND: Obstructive sleep apnea (OSA) may lead to myocardial preconditioning by increasing coronary collateral vessel recruitment in patients with acute coronary occlusion. AIM: To determine the relationship between the severity of obstructive sleep apnea and coronary collaterality during acute myocardial infarction. METHODS: This study prospectively included 71 patients with an inaugural myocardial infarction who had undergone a coronary angiography within 24h of onset. All patients underwent an overnight polygraph before discharge and were classified according to the apnea-hypopnea index (AHI). Coronary collaterals were scored by visual analyses and according to the Rentrop grading system. RESULTS: Mean age was 59±11years and 83% of patients were men. All patients had complete or subtotal occlusion of the infarct-related artery. After the sleep study, patients were divided into two groups: 25 were suffering from OSA (AHI>15/h). Patients with OSA showed better collateral vessel development (Rentrop score≥1) compared to non-OSA patients (68 vs. 41%, P=0.032). AHI was significantly higher in patients with developed coronary collaterals (Rentrop≥1) compared to those without collaterality (17.74±13.2 vs. 12.24±10.9, P=0.025). CONCLUSION: Coronary collateral development may be increased in OSA patients who are presenting with a first myocardial infarction.

[Measurement of d-dimers in non-valvular atrial fibrillation. First prospective Tunisian study]. / Intérêt du dosage des d-dimères dans la fibrillation atriale non valvulaire. Première série prospective tunisienne.

Atrial fibrillation can expose to thrombo-embolic complications. Many biomarkers have been tested to refine the stratification of thrombo-embolic risk. The study aim was to assess the interest of the d-dimer testing in this pathology. We conducted a prospective observational study including 50 cases and 19 controls, enrolled at the cardiology department of the Mongi Slim Hospital, from July to November 2012. The d-dimer assay was performed on mini-VIDAS(®) and analyzed according to clinical, echocardiographic and biological data. The mean age of patients was 61.8±10.6years. The mean CHA2DS2-VASc score was 2.58±1.31. The average of D-dimer levels was 590±506ng/ml in patients and 225.26±112.95ng/ml in controls (P=0.02). No significant difference has been found between the d-dimer level and age, sex, type and etiology of atrial fibrillation, the CHA2DS2-VASc score, the left atrial surface. Among patients on acenocoumarol, d-dimer levels was significantly higher in patients with an INR<2 compared to those with an INR≥2 (P=0.004). We identified a positive d-dimer threshold (300ng/ml) in patients distinguishing them significantly with controls (P<0.001). In conclusion, the measurement of d-dimers could help clinicians to identify patients with atrial fibrillation having an increased coagulability and, therefore, an increased thrombo-embolic risk. It could be complementary to the determination of INR in monitoring anticoagulation therapy: d-dimers level refines the thrombo-embolic risk and INR measurement assesses the level of anticoagulation and the bleeding risk.

[Diagnostic accuracy of Epworth sleepiness scale in the acute phase of myocardial infarction]. / Intérêt du score d'Epworth à la phase aiguë d'infarctus du myocarde.

BACKGROUND: Obstructive sleep apnea syndrome (OSAS) is underdiagnosed in cardiologist daily practice, especially in patients with acute coronary syndrome. Its diagnosis is based on a polysomnography study. The Epworth Sleepiness Scale (ESS) stands as a simple and rapid means to select patients for the sleep investigation. AIM: The aim of this study was to determine the diagnostic accuracy of the ESS for screening OSAS in patients with ST elevation myocardial infarction. METHODS: We conducted a prospective study of 120 consecutive patients admitted for acute myocardial infarction, from April 2011 to March 2012. Daytime sleepiness was evaluated using the ESS, when patients were in the intensive care unit. All patients have undergone an overnight sleep study using a portable diagnostic device, in the 15 days following the acute coronary syndrome. The diagnostic of OSA was considered as apnea-hypopnea index (AHI) of ≥5 events/hour, severe OSA was defined as AHI of ≥30. RESULTS: The study included 120 patients comprising 102 men and 18 women. The mean age was 58 ± 12 years. Smoking was the major cardiovascular risk factor with 72% of all patients; prevalence of diabetes was 40% and hypertension was found in 44% of the population. The prevalence of OSA was 79%. Severe OSA was diagnosed in 16% of all patients and mean AHI was 15.76 ± 14.93. Mean ESS was 2.2 ± 1.84 in the global population while it was 5.2 ± 1.2 in patients with severe OSAS. Multivariate analysis showed that ESS score ≥ 4 was an independent predictive factor for severe OSA (OR=28; 95% IC: 8-101; P<0.001). CONCLUSION: The prevalence of OSA in patients with acute myocardial infarction was very high. ESS score ≥ 4 was an independent predictive factor for severe OSA. Despite its subjective feature, the ESS seems to be an interesting score for screening patients to undergo polysomnography.

[Prevalence and predictors of obstructive sleep apnea in patients admitted for acute myocardial infarction]. / Prévalence et facteurs prédictifs du syndrome d'apnée obstructive du sommeil au décours de l'infarctus du myocarde.

BACKGROUND: Obstructive sleep apnea has been implicated in the pathogenesis and aggravation of coronary atherosclerosis. However, it remains underdiagnosed in cardiology practice. AIM: The aim of this study was to determine the prevalence of obstructive sleep apnea and the predictors of severe sleep apnea in patients admitted for ST elevation myocardial infarction. METHODS: This was a prospective study which has included 120 patients hospitalized for ST elevation myocardial infarction, from April 2011 to March 2012. All patients have undergone an overnight sleep study using a portable polygraphy device, in the 15 days following the acute coronary syndrome. The diagnostic of obstructive sleep apnea was considered as apnea-hypopnea index of ≥ 5 events per hour, severe sleep apnea was defined as apnea -hypopnea index of ≥ 30. Subjective daytime sleepiness was assessed by the Epworth sleepiness scale. All patients have had an oxygen saturation monitoring in the coronary care unit using a pulse oxymeter, before undergoing the sleep study. RESULTS: The study population was made up of 102 men and 18 women. The mean age was 58 ± 12 years. Smoking was the major cardiovascular risk factor found in 72% of all patients, diabetes and hypertension were represented in 40% and 44% of the population, respectively. Eighty-seven percent of patients were admitted in the first 24 hours of symptom onset. A primary percutaneous coronary intervention was performed in 60% of cases while fibrinolysis was done in 10% of patients. The prevalence of obstructive sleep apnea was 79%. Mean apnea-hypopnea index was 15.76 ± 14.93 and severe form was diagnosed in 16% of all patients. Multivariate analysis showed that Epworth sleepiness score of ≥ 4 and nocturnal desaturation below 82% were independent predictive factors for severe obstructive sleep apnea. CONCLUSION: Prevalence of obstructive sleep apnea was very high in patients admitted for acute myocardial infarction. Epworth sleepiness score of ≥ 4 and nocturnal desaturation below 82% were independent predictive factors for severe form of sleep apnea.

[Role of multidetector CT scan in the diagnosis of congenital coronary artery anomalies with inter-aortopulmonary course: about two cases and literature review]. / Apport du scanner multibarrettes dans la détection des anomalies de naissance des artères coronaires avec trajet inter-aortopulmonaire : à propos de deux cas et revue de la littérature.

Coronary anomalies are a rare entity. The gold standard remains the coronary angiogram. However, the identification of the origin and the course of aberrant coronary arteries using angiography may be difficult. We report two cases regarding two patients who underwent coronary angiography in order to evaluate coronary heart disease. In the first case, angiography has shown a left anterior descending artery (LAD) originating from the right anterior sinus. A multidetector CT scan (MDCT) showed an inter-aortopulmonary course of the LAD. In the second case, selective catheterization of the right coronary artery could not be done. A MDCT scan was performed. An abnormal origin of the right coronary artery was detected. It originates from the left sinus with a separate ostium of the left main coronary artery. This artery had an inter-aortopulmonary course. The 64 MDCT scan can be useful as a complementary tool for the diagnosis of coronary artery anomalies. Detection of the inter-aortopulmonary course is essential, since this situation will require surgical treatment to avoid sudden cardiac death.

[Myocardial infarction after conduction electrical weapon shock]. / Infarctus du myocarde suite à une électrisation par pistolet à impulsion électrique.

Controversy persists over the safety of conducted electrical weapons, which are increasingly used by law enforcement agencies around the world. We report a case of 33-year-old man who had an acute inferior myocardial infarction after he was shot in the chest with an electrical weapon.

[Peripartum cardiomyopathy]. / La cardiomyopathie du péripartum.

Peripartum cardiomyopathy is a rare and under recognized form of dilated cardiomyopathy, defined as a heart failure in the last month of pregnancy or in the first five months post-partum with absence of determinable cause for cardiac failure and absence of demonstrable heart disease. The incidence of peripartum cardiomyopathy ranges from 1 in 1300 to 1 in 15,000 pregnancy. Advanced maternal age, multiparity, twin births, preeclampsia and black race are known risk factors. The etiology of peripartum cardiomyopathy remains unknown but viral, autoimmune or idiopathic myocarditis are highly suggested. The clinical presentation on patients with peripartum cardiomyopathy is similar to that of patients with systolic heart failure. The treatment is based on drugs for sympyomatic control. Studies in graeter populations are need to determine the role of immunosupressive treatment. About half patients of peripartum cardiomyopathy recover. The left ventricular ejection fraction and the left ventricular end-diastolic diameter are statistically significant prognostic factors. The risk of developing peripartum cardiomyopathy in subsequent pregnancies remains high. The place of dobutamine stress test in counseling the patients who desire pregnancy must be more studied.

[Multicenter study of atrial fibrillation]. / La fibrillation auriculaire. Etude multicentrique.

1134 patients presented a first episode of atrial fibrillation (AF) between January 1985 and December 2000. Age average was 58.6 years (15-60). 656 (57.8%) were male and 478 (42.2%) were female. The first etiology of AF was rheumatic carditis (36.1%). AF was idiopathic in 27.7% of cases. Morbi-mortality was significantly higher in patients with AF versus those with sinus rhythm; five years survival was respectively 96% and 85%. Success rate was 70% with electrical cardioversion versus 40% with pharmacological cardioversion. Results of AF reduction was independent of left atrium diameter. Only long standing of AF predicted failure of AF reduction.

[Prognostic value of high-sensitivity C-reactive protein in assessing intrahospital outcome of unstable angina]. / L'intérêt de la CRP ultrasensible dans l'évaluation du pronostic intrahospitalier de l'angor instable.

Inflammation has been shown to play an important role in the pathogenesis of unstable angina. CRP has been demonstrated to be a reliable marker of prognosis is unstable angina. The aim of this study was to investigate the prognostic value of CRP in assessing short outcome of unstable angina. Our study is a prospective double blinded one. We measured CRP in 33 consecutive patients admitted for unstable angina at the 24th and 48th hour. The mean age is 60 years (30 to 84 years). There were 22 men and 11 women. 8 patients were included in class I of Braunwald classification, 5 were in class II and 20 in class III. 14 patients presented cardiac events. The CRP mean value was significantly higher among these patients (12 mg/l vs 5 mg/l, p < 10.4). Patients having a CRP > or = 3 mg/l have a higher risk of developing complications (66% vs 13%, p = 0.002). Elevation of CRP predicted poor outcome of intrahospital evolution with a sensitivity of 86%, a specificity 68%, a positive and negative predictive values of 66% and 86%. The CRP in our preliminary study is an independent risk factor of early outcome of unstable angina. In association with clinical scores and other cardiac markers will lead to a better identification of high risk patients.

[Brugada syndrome]. / Le syndrome de Brugada.

The Brugada syndrome is a clinical-electrocardiographic diagnosis characterised by syncopal or sudden death episodes in patients with a structurally normal heart with a characteristic electrocardiographic pattern consisting of ST segment elevation in the precordial leads V1 to V3 and a morphology of the QRS complex resembling a right bundle branch block. In many patients with the Brugada syndrome, the electrocardiographic manifestations transiently normalize; leading to underdiagnosis of the syndrome. The administration of sodium channel blockers such as ajmaline, flecainide or procainamide accentuate the ST segment elevation and can be used to unmask concealed and intermittent forms of the disease. The incidence of sudden death in this syndrome is very high and can only be prevented by implanting a cardioverter-defibrillator. Because of high incidence of familial occurrence, the extension of the testing to family members is important.

[Auricular fibrillation]. / La fibrillation auriculaire.

There is many progresses in term of comprehension of physiopathologic mechanisms and also therapeutic indications. The increase of treatment modalities need a clear strategy and an adapted choice from pharmacologic, to surgical, external electric shock, prophylactic cardiac stimulation, implantable auricular defibrillation, and ablative methods.

[Sinoatrial block induced by therapeutic doses of diltiazem. Report of 3 cases]. / Bloc sino-auriculaire induit par le diltiazem aux doses therapeutiques. A propos de trois observations.

We report three observations of Diltiazem intoxication at therapeutic doses with occurence of sino auricular block. The situation evolute favorably for two patients while the third die. The electro systolic stimulate seems to be justified in case of Diltiazem intoxication.

[Hypertrophic cardiomyopathy and pregnancy]. / Cardiomyopathie hypertophique et grossesse.

We report the case of a 32 years old patient, with a known diagnostic of hypertrophic cardiomyopathy; who has presented at the first trimester of pregnancy a ventricular fibrillation treated by electric shock with a favorable outcome. The risks for the mother and the foetus are discussed; The recommendations for the conduct of the delivery are reviewed.

[Cardiac insufficiency with normal systolic function]. / Insuffisance cardiaque à fonction systolique conservée.

Cardiac failure with normal systolic function represents 30 to 50% of all the cardiac failures. Ther is no clinical radiographical electrocardio graphical symptom to characterize this Kind of Cardiac failure. It's diagnosis and its valuation could be done with doppler chocardiography. The etiology is dominated by the ischemic cardopathy, the hpertophic myocardis fathies and senile heart. It's treatment isn't codified Yet.

[Prognosis and treatment of chronic cor pulmonale]. / Pronostic et traitement du coeur pulmonaire chronique.

We have report one hundred cases of chronic pulmonary heart observed between 1982 and 1991. Mean age was 63 years, 61% were men. COPD was the most frequent etiology of CP (84%) before restrictive (14%) and thromboembolic diseases (2%). Diuretics were used in all patients, nifedipine in 32% and digitalis in 16%. Eleven patients died during their first admission, and six died later. Only 31 patients are still regularly.