[Circadian and septadian variation in sudden cardiac death : Autopsy registry of the Tunisian North]. / Variation circadienne et hebdomadaire de la mort subite d'origine cardiaque : registre autopsique du nord de la Tunisie.

INTRODUCTION: Several studies have suggested a circadian and septadian pattern of incidence of sudden cardiac death with a morning peak and a Monday peak. OBJECTIVE: To analyze the circadian and septadian pattern of occurrence of sudden cardiac death in the eight northern Tunisian governorates. METHODS: We prospectively collected epidemiological and autopsy data of sudden cardiac death victims occurring in the northern region of Tunisia between January 2013 and December 2019. RESULTS: The population included 1834 men (79.6%) and 468 women (20.4%) with a mean age of 56.5 ± 14 years. Smoking (53.9%) was the most prevalent cardiovascular risk factor. One-fifth (20.9%) of victims had known heart disease, and 3% had a family history of sudden death. ischemic heart disease was the leading cause of sudden death (46.8% of cases). One- fourth (25.7%) of autopsies were negative. Analysis of the circadian pattern of occurrence of sudden cardiac death identified a peak (36.1%, p < 0.001) between midnight and 6 am. This nocturnal excess mortality was significant (p < 0.001) and independent of sex (34.1 % in men and 43.8 % in women) and cause of death (39.3 % of cases of sudden ischemic death and 33.3 % of cases of nonischemic death). Moreover, there was a significant septadian variability in the occurrence of sudden death (p: 0.0015), with a peak on Friday (15.8 %, p: 0.042). CONCLUSION: This study showed a peak of sudden death between midnight and 6 am, and on Fridays, confirming the modification of the classic circadian and septadian pattern of sudden death occurrence. These results may help optimize the deployment of emergency mobile teams and structures during the most vulnerable periods.

Multivessel spontaneous coronary artery dissection with simultaneously three different angiographic patterns.

Spontaneous coronary artery dissection (SCAD) is a non-traumatic non-iatrogenic coronary dissection. It's a frequent cause of acute coronary syndrome (ACS) in women without or with few traditional cardiovascular risk factors. We report an unusual case of multivessel SCAD in a middle-aged woman with successful medical management.

[Myocardial infarction in the young : clinical characteristics, therapeutic aspects and in-hospital complications.] / Infarctus du myocarde chez le sujet jeune en Tunisie : caractéristiques cliniques, aspects thérapeutiques et complications intra-hospitalières.

AIM OF THE STUDY: The aim of our study was to assess the clinical, electrical, angiographic and therapeutic characteristics of young patients with acute myocardial infarction and to describe the prevalence of in-hospital complications. PATIENTS AND METHODS: FromJanuary 2014 to May 2017, we retrospectively studied data of patients with acute myocardial infarction younger than 45 years old in the department of cardiology of Charles Nicolle hospital of Tunis. RESULTS: We enrolled 108 patients in the study. The prevalence of myocardial infarction in young patients was 8.5%. The mean age was 39.5 ± 5.5 years with a sex-ratio of 11. The most frequent cardiovascular risk factors were smoking (88%) and dyslipidaemia (51.9%). We reported 75 cases of ST segment elevation myocardial infarction. Primary angioplasty was performed in 41.3% of cases while lytic therapy was administered for the rest of the patients. It was successful in 75% of cases. Among 33 patients who presented with non-ST segment elevation myocardial infarction, percutaneous coronary angioplasty was performed in 60.6% of patients while 15.2% have undergone coronary artery bypass surgery and 24.2% received medical treatment only. In-hospital complications occurred in 39.8% of cases. In-hospital mortality was 1.9 %. CONCLUSIONS: Acute myocardial infarction in the young represents a serious health problem. Primary preventive measures aimed at preventing our youth from adopting tobacco use and developing dyslipidemia should be implemented to delay and even to avoid the onset of coronary artery disease.

[Relationship between arterial stiffness and the severity of coronary artery disease in acute coronary syndrome]. / Relation entre la rigidité artérielle et la sévérité du statut coronaire après un syndrome coronaire aigu.

BACKGROUND: The association between arterial stiffness (AS) and stable coronary artery disease (CAD) has been previously demonstrated. Whether increased arterial stiffness is associated with severe CAD in patients with acute coronary syndrome (ACS) is less explored. AIM: We aim to investigate the relationship between AS parameters and the extent and severity of CAD in patients with ACS. METHODS: The study population consisted of 275 patients with ACS. We measured various AS parameters including pulse wave velocity (PWV), augmentation index (AIx), and central pulse pressure (cPP). CAD extent and severity was evaluated by the number of vessels with greater than 70% stenosis. RESULTS: The study population was predominantly men (77, 5%) with an average age of 56, 4±10, 6 years. One hundred and fifteen patients were diabetic and 97 were hypertensive. One hundred fifty patients were admitted for ST elevation myocardial infarction (54, 5%) and 37, 5% for non ST elevation myocardial infarction. Thirty six percent of patients had single vessel disease and 47, 6% of the study population had multivessel disease. At the multivariate analysis, a positive correlation was observed between the number of coronary vessels disease and PWV. PWV (OR=1,272; IC95% [1,090; 1,483]; p=0,002) and cPP (OR=1,071; IC95% [1,024; 1,121]; p=0,003) were also independent predictors of multivessel disease. CONCLUSION: In patient with ACS, PWV is correlated with the extent of coronary artery disease, as measured by the number of vessels disease. PWV and cPP were also independent predictors of multivessel disease.

[Sudden cardiac death in women, data from the northern Tunisian sudden cardiac-death registry]. / La mort subite cardiaque chez la femme, registre du nord de la Tunisie.

BACKGROUND: Sudden cardiac death is a major public health problem. Epidemiological and clinical differences according to gender have been described in sudden cardiac death. The aim of this study was to examine the gender differences between autopsy findings and circumstance of occurrence associated with sudden cardiac death. METHODS: We prospectively collected epidemiological and autopsy data of victims of sudden cardiac death occurring in the northern governorates of Tunisia between January 2013 and December 2019. Symptoms preceding death, circadian, weekly and seasonal variations of sudden death were also analyzed. RESULTS: The study population included 1834 men and 468 women with a mean age of 56.5±14.2 years. All cardiovascular risk factors except smoking were significantly more frequent among women but ischemic heart disease was the most common cause of death in men (51.3 %, versus 28 %, P<0.001). Women were more likely to have a negative macroscopic autopsy than men (34 % versus 23.6 %, P<0.001). Chest pain preceding sudden death was more frequent in male (24 % versus 13.2 %, P<0.001). In contrast, women were more likely to have dyspnea (8.1 % versus 15.6 %, P<0.001). Sudden death in women occurred indoors more often than in men (63.9 % versus 54.5 %, P<0.001) and also more often during night (midnight to 6 am). We also recorded an excess cardiac mortality in winter in both sexes. CONCLUSIONS: Women had considerably more cardiovascular risk factors and more commonly negative macroscopic autopsy. Death occurred indoors and during night more often than in men.

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.

[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.

[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.

[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.

Blue light effects on rose photosynthesis and photomorphogenesis.

Through its impact on photosynthesis and morphogenesis, light is the environmental factor that most affects plant architecture. Using light rather than chemicals to manage plant architecture could reduce the impact on the environment. However, the understanding of how light modulates plant architecture is still poor and further research is needed. To address this question, we examined the development of two rose cultivars, Rosa hybrida'Radrazz' and Rosa chinensis'Old Blush', cultivated under two light qualities. Plants were grown from one-node cuttings for 6 weeks under white or blue light at equal photosynthetic efficiencies. While plant development was totally inhibited in darkness, blue light could sustain full development from bud burst until flowering. Blue light reduced the net CO(2) assimilation rate of fully expanded leaves in both cultivars, despite increasing stomatal conductance and intercellular CO(2) concentrations. In 'Radrazz', the reduction in CO(2) assimilation under blue light was related to a decrease in photosynthetic pigment content, while in both cultivars, the chl a/b ratio increased. Surprisingly, blue light could induce the same organogenetic activity of the shoot apical meristem, growth of the metamers and flower development as white light. The normal development of rose plants under blue light reveals the strong adaptive properties of rose plants to their light environment. It also indicates that photomorphogenetic processes can all be triggered by blue wavelengths and that despite a lower assimilation rate, blue light can provide sufficient energy via photosynthesis to sustain normal growth and development in roses.

[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.

[Study of cardiovascular risk factors in Tunisian patients with recent type 2 diabetes]. / Étude des facteurs de risque cardiovasculaire chez le diabétique de type 2 Tunisien récemment découvert.

OBJECTIVE: To study the frequency of silent myocardial ischemia (SMI) in Tunisian patients with recent type 2 diabetes and identify cardiovascular risk factors directly in relation with SMI. PATIENTS AND METHODS: One hundred and twenty diabetics and sixty healthy people have benefited from blood sampling, electrocardiogram and exercise test. RESULTS: The frequency of SMI was 21% in diabetics and 3% in healthy people (P=0.01). Obesity and hypertension were higher in diabetics than in healthy people (P=0.001 and P<10(-4)). Using unvaried analysis for risk factors with the presence of SMI in diabetics, we found that age greater than 60 yrs, male sex, sedentary and smoking were significantly correlated with SMI; respectively P=0.004, 0.01, 0.009 and 0.03. The SMI was found in 37% of diabetics with high blood pressure vs 8% in diabetics with normal blood pressure and was correlated with hypertriglyceridemia, hypoHDLemia and microalbuminuria. Patients with SMI had at least two cardiovascular risk factors apart from diabetes among those: age greater or equal to 60 yrs, male sex, smoking, hypertension, dyslipidemia and family history of early coronaropathy. Chronic inflammation and hyperhomocysteinemia were significantly correlated to SMI; OR=4.2 and 3.8. In addition, SMI was found in one diabetic over three who had bad glycemic control. Using multivariate analysis, only age greater or equal to 60 yrs, smoking, hypertension, hyperhomocysteinemia and hypertriglyceridemia were risk factors directly in relation with SMI in type 2 diabetes. CONCLUSION: The assessment of global cardiovascular risk from the moment of discovering type 2 diabetes and the early screening of SMI should be necessary.