Covid-19 et système cardiovasculaire / Covid-19 and cardiovascular system

L'expansion planétaire du covid19 représente une crise sans précèdent ; cette pandémie a fait plus d'un million de mort en une année. En plus de l'atteinte pulmonaire, le virus a des implications majeures sur le système cardiovasculaire : les maladies cardiovasculaires pré existantes représentent un facteur de risque d'infection sévère avec augmentation de la mortalité, d'autre part l'infection entraine des complications cardiovasculaires qui aggravent le pronostic. Le lien entre le Covid19 et le système cardiovasculaire découle principalement de la voie d'entrée cellulaire du virus qui est assurée par sa liaison à une protéine membranaire l'enzyme de conversion de l'angiotensine (ECA), qui joue un rôle clé dans la régulation neurohumorale ; cette protéine est très présente au niveau du cœur et du poumon, d'où le tropisme du virus qui entraine la dysrégulation de cette voie cellulaire avec des répercussion sur la fonction cardiaque et respiratoire. Une polémique a déferlé concernant les traitements anti hypertenseurs et notamment les inhibiteurs du système rénine angiotensine aldostérone mais après évaluation des données actuelles, il est de consensus de ne pas arrêter ou changer les traitements anti hypertenseurs. L'augmentation des troponines cardiaques est un facteur de mauvais pronostic qui aggrave le tableau. La myocardite est définie par une inflammation myocardique, Les tableaux cliniques sont variables de la forme légère à la forme grave ; les biomarqueurs myocardiques restent un test incontournable en cas de suspicion clinique, le pronostic est incertain avec des formes fulminantes qui peuvent régresser et enfin pour le traitement les corticoïdes semblent être efficaces. Une autre complication du virus sont les accidents thrombo-emboliques et le dilemme occasionné par le risque accru aux thromboses et la thrombopénie induite par l'utilisation de l'héparine (TIH). On note une augmentation de l'incidence des syndromes coronaires aigus chez les sujets atteints du covid19.

The global expansion of covid19 represents a global crisis; this pandemic killed more than a million people in one year. In addition to pulmonary involvement, the virus has major implications on the cardiovascular system: pre-existing cardiovascular diseases represent a risk factor for severe infection with increased mortality, on the other hand the infection causes cardiovascular complications which worsen the prognosis. The link between the Covid19 and the cardiovascular system stems primarily from the virus's cellular entry pathway, which is provided by its binding to a membrane protein, the angiotensin converting enzyme (ACE) wich plays a key role in neurohumoral regulation; this protein is very present in the heart and lungs, hence the tropism of the virus which causes the dysregulation of this cellular pathway with repercussions on cardiac and respiratory function. A controversy broke out concerning the antihypertensive treatments and in particular the inhibitors of the renin angiotensin aldosterone system but after evaluation of the current data, there is a consensus not to withhold or change the treatments. The increase in cardiac troponins is a factor of poor prognosis which worsens the picture. Myocarditis is defined by myocardial inflammation, its clinical form ranges from the mild form to the severe one; the myocardial biomarkers remain an essential when the clinical suspicion rise, the prognosis is uncertain with fulminant forms which can regress; for treatment corticosteroids seem to be effective. Another complication of the virus are thromboembolic events and the dilemma caused by the increased risk of thrombosis and thrombocytopenia induced by the use of heparin (TIH), and there is an increase in the incidence of acute coronary syndromes in patients affected by covid19.

Review of cardiovascular involvements in COVID-19

Background: A spectrum of cardiovascular pathologies occurs in patients with COVID-19 and increases the risk of mortality. Risk of mortality is also heightened in cardiovascular disease patients who contact COVID-19. Methodology: Online search for the keywords in PubMed, Medline, Embase, Google scholar was done. Relevant research articles yielded from the searches were reviewed. Results: the searches yielded a total of 172 results, out of which 111 were reviewed. Cardiac involvement was found in 70.6% COVID-19 patients: tachycardia (19%), electrocardiography abnormalities (22%), echocardiography abnormalities (57%), elevated myocardial enzymes (53%), and acute cardiac injury (9%). Eight percent of patients with acute cardiac injury were aged >60 years; 87.5% of them had ≥2 underlying comorbidities (hypertension, diabetes mellitus, cardiovascular diseases, chronic obstructive pulmonary disease, and chronic kidney disease). Novel coronavirus pneumonia was much more severe in the patients with acute cardiac injury than in patients with non-definite acute cardiac injury (P<0.001). Multivariate analyses showed that C-reactive protein (CRP) levels, old age, novel coronavirus pneumonia severity, and underlying comorbidities were the risk factors for cardiac abnormalities in patients with COVID-19. Conclusion: Besides its prominent expression at the level of the respiratory apparatus, COVID-19 is also characterized by a substantial degree of cardiovascular involvement, both in terms of deterioration of pre-existing conditions, and as the effect of inflammation-facilitated acute events. They include ischemic and inflammatory heart disease, ventricular arrhythmias, conduction disturbances, thrombotic events at the level of the lungs, systemic activation of the coagulation cascade and disseminated intravascular coagulation.

Prévalence des facteurs de risque cardiovasculaire et leur association avec les facteurs socio-économiques dans une population marocaine atteinte du syndrome coronarien aigu

Le but de la présente étude était d'évaluer la prévalence des facteurs de risque cardiovasculaires conventionnels et leur association avec des facteurs socio-économiques dans une population traitée pour un syndrome coronarien aigu, au département de car¬diologie du CHU Ibn Rochd de Casablanca au Maroc. Méthode : L'étude a été réalisée chez 199 patients consécutifs au cours de la phase aiguë d'un syndrome coronarien aigu. Les critères d'inclusion étaient l'ad¬mission dans les 24 heures après le début de la dou¬leur thoracique. Le facteur de risque cardiovasculaire conventionnel le plus courant chez ces patients était essentiellement le tabagisme, suivi de l'hypertension artérielle et du diabète de type II. Résultats : La prévalence de l'hypertension et du diabète était plus élevée chez les femmes atteintes du syndrome coronarien aigu que chez les hommes. Cette différence s'est également maintenue après ajustement en fonction de l'âge. Une fréquence plus élevée d'individus avec un stress au travail faible et modéré que des individus présentant des niveaux de stress au travail élevés a été observée. Cependant, les femmes qui souffraient d'un syndrome corona¬rien aigu avaient un niveau de stress au travail plus élevé que les hommes. Cette différence statistique a disparu lorsque l'âge a été utilisé comme covariant. Il n'y avait pas de différence statistique dans l'acti¬vité physique liée au travail entre les hommes et les femmes. De plus, il n'y avait aucune association entre le niveau de stress au travail, l'activité physique liée au travail et les facteurs de risque cardiovasculaires conventionnels. Conclusion : Les facteurs de risque conventionnels les plus répandus chez les patients atteints du syn¬drome coronarien aigu inclus dans l'étude étaient le tabagisme actuel, le diabète et l'hypertension. Les femmes présentaient des niveaux de stress au travail plus élevés que les hommes. Cependant, les facteurs socioéconomiques n'étaient pas associés à la préva¬lence des facteurs de risque cardiovasculaires conven¬tionnels chez les hommes et les femmes

Assessment of ultrasound flow-mediated dilation of brachial artery in regular blood donors in a Nigerian Tertiary Hospital

Background: Iron is a pro-oxidant cofactor that may be linked to cardiovascular disease (CVD) progression and reduction of body iron stores have been hypothesized to reduce the risk of CV disease. Aim: The aim of this study is to assess reduction in CVD risk susceptibility among regular blood donors compared with nondonors using ultrasound brachial artery flow-mediated dilation (BAFMD). Settings and Design: A prospective comparative study designed to establish the difference between mean flow-mediated dilatation (FMD) in the patients who are regular blood donors compared with nondonors recruited from a Teaching Hospital donor clinic. Materials and Methods: Data were collected over 7 months from December 2014 to June 2015. 100 eligible regular male blood donors, aged 21­50 years, were selected from a Teaching Hospital blood donor records and their BAFMD assessed. 50 nondonors/ first time donors, of equivalent age group, consecutively were assessed for comparison. Serum markers of iron stores, markers of oxidative stress and other related cardiac risk factors were also assessed in all patients. Results: BAFMD was significantly greater in regular blood donors when compared with nondonors (13.95% ± 7.02% vs. 8.20% ± 4.19%, P = 0.000). Serum ferritin was significantly decreased in regular blood donors when compared with nondonors (mean value 41.92 ng/ml ± 23.12 ng/ml vs. 61.97 ± 30.19 ng/ml, P = 0.000), but Hb did not differ between the groups. High FMD was significantly associated with high C-high-density lipoprotein and low C-LDL (r = −0.215*, P = 0.032, r = 0.188, P = 0.031, r = 0.193, P = 0.027, r = 0.0279, P = 0.002, r = 0.139, P = 0.084). LDL was decreased in regular blood donors compared with nondonors. Conclusion: The study provides prognostic information for assessing ultrasound BAFMD as a cardiac risk marker. Regular blood donors have enhanced cardiovascular function with increased flow-mediated dilation, decreased body iron stores, and decreased oxidative stress compared with nondonors

Systematic Chest Radiography during Pre-Employment Check-Up

The aim of this study was to specify the importance of chest radiography during pre-employment check-ups in the tropical environment. A cross-sectional study of chest X-rays of 2540 apparently healthy job applicants in seven private companies in Abidjan; Cote d'Ivoire; was carried out over a 5-year period. The chest X-rays were performed in posterior-anterior; frontal; standing position. Two senior radiologists performed a double-blind study in search of parietal; mediastinal; and pleuroparenchy-matous abnormalities. The 2540 subjects were all males with ages ranging between 20 and 36 years. In 93of the cases (2372 job applicants) the frontal chest X-ray was normal but 168 (7) presented abnormal images. The observed lesions were dominated by cardiomegaly (102 cases) followed by pulmonary parenchymatous lesions (35 cases); and by pleural liquid effusions (10 cases). The parenchymatous abnormalities were represented by 35 evolutional lesions in the form of 12 apical parenchymatous infiltrates; 7 excavated apical pneumopathies; and 16 non-excavated condensations. The 10 cases of pleural abnormality were encysted pleuritis. Frontal chest radiology can be useful in pre-employment check-ups in the tropical environment by helping to screen for contagious pulmonary lesions that may be undetected at a clinical examination

Hypertensive Crisis

Hypertension is a common medical problem. It affects approximately one in four adults worldwide; with evidence that the prevalence is rising. In the USA; approximately 30 of adults have some form of hypertension.1 It is estimated that 1-2 of the hypertensive population will present with an acute and severe elevation of blood pressure at some stage; i.e. hypertensive crisis: systolic blood pressure 180 mmHg; or diastolic blood pressure 120 mmHg.2

Hypertension

Approximately one in four adults has hypertension; a prevalence that increases with age and may reach to two out of three adults older than 70 years of age. In the Framingham Heart Study 65-75 of hypertension in the elderly is of the isolated systolic hypertension variety. Hypertension causes a two- to threefold increased risk of atherosclerotic cardiovascular events. Hypertension clusters with dyslipidaemia; insulin resistance; glucose intolerance and obesity in more than 80 of cases.1 The great majority of hypertensives thus have additional cardiovascular risk factors. The global cardiovascular risk; of which hypertension is but one component; is best appreciated by the use of risk charts such as the Framingham Risk Score

Impact of Income on the Profile of Cardiovascular Risk Factors among Hypertensives in a Nigerian Tertiary Health Centre: a Cross-Sectional Study : Cardiovascular Topics

Background: In most developed countries; risk factors for cardiovascular diseases (CVD) are more prevalent in low socioeconomic classes. However; the pattern in developing countries appears to be different. This study sought to evaluate and compare risk factors for CVD as well as absolute CVD risk in hypertensive subjects grouped by income in Kano; Nigeria. Methods: The study was cross-sectional in design and carried out in Aminu Kano Teaching Hospital; Kano; Nigeria. Seventy treatment-naIve hypertensives and an equal number of hypertensives on treatment were recruited by balloting from the outpatient clinics; and then regrouped into low- and high-income earners. These two groups were then compared in terms of their profile of CVD risk factors and absolute CVD risk. All the assessed CVD risk factors are recognised in standard guidelines for the management of persons with systemic hypertension. Results: The low-income group comprised 45 patients (32.1) while the remaining 95 (67.9) had a high income. The most prevalent CVD risk factor was dyslipidaemia; found in 77.8 and 71.6of low- and high-income earners; spectively (p = 0.437). The prevalence of proteinuria was significantly higher among low-income earners (42.2) compared with high-income earners (15.8) (p = 0.001). Mean serum creatinine was also higher among low-income earners but the difference did not reach statistical significance (p = 0.154). Very high CVD risk was found in 75.6 and 70.5of low- and high-income earners; respectively (p = 0.535). Conclusion: Dyslipidaemia and very high CVD risk were found in over 71of the patients regardless of their level of income. Low-income earners had a higher prevalence of indices of renal damage. These findings pose a great challenge to the present and future management of all subjects; particularly those in the low-income group; given that in Nigeria; healthcare is largely paid for directly out of their pockets

Cardiovascular Effects of Helichrysum ceres S Moore [Asteraceae] Ethanolic Leaf Extract in Some Experimental animal Paradigms : Cardiovascular Topic

The aim of this study was to examine some in vivo and in vitro cardiovascular effects of Helichrysum ceres leaf ethanolic extract (HCE) in experimental animal paradigms. The acute effects of HCE on blood pressure were studied in anaesthetised normotensive male Wistar rats challenged with intravenous hypotonic saline infusion after a 3.5-hour equilibration for four hours of one-hour control; 1.5-hour treatment and 1.5-hour recovery periods. HCE was added to the infusate during the treatment period. Sub-chronic hypotensive effects of HCE were examined in weanling Dahl Salt-sensitive (DSS) genetically hypertensive rats; which progressively develop hypertension with age; treated with HCE (80 mg / kg) every third consecutive day for seven weeks. isolated atrial muscle strips; portal veins and descending thoracic aortic rings of healthy normotensive Wistar rats were used to investigate the vascular effects of HCE. Acute HCE administration caused a significant (p 0.05) fall in blood pressure in the normotensive anaesthetised Wistar rats. DSS hypertensive rats treated with HCE displayed low arterial blood pressure and heart rate values from weeks five to seven. HCE produced concentration-dependent negative inotropic and chronotropic effects on rat isolated electrically driven left; and spontaneously beating right atrial muscle preparations; respectively. HCE also evoked concentration-dependent relaxation responses of endothelium-intact aortic rings and portal veins isolated from healthy normotensive Wistar rats. The vasorelaxant effects of HCE in intact aortic rings were significantly reduced; but not completely abolished by adding endothelial-derived factor (EDRF) inhibitor; L-NAME; suggesting that the vasorelaxant effect of the extract is mediated via EDRF-dependent and independent mechanisms. The results of the study suggest that the hypotensive action of HCE is elicited; in part; directly by decreasing myocardial contractile performance and total peripheral vascular resistance due to its negative inotropic and chronotropic effects on rat isolated atrial muscle strips; and vasorelaxant effects on isolated vascular smooth muscles. The observed cardiovascular effects of HCE partly support the basis for its use in the management of high blood pressure in folkloric medicine

The G-308A Polymorphism of the TNF-? Gene Does not Predict Changes in Cardiac Function in Response to Medical Therapy for Idiopathic Dilated Cardiomyopathy

The G-308A polymorphism of the tumour necrosis factor-? (TNF-?) gene; a variant that influences TNF-? transcription; may contribute to non-ischaemic dilated cardiomyopathy. To evaluate whether TNF-? genotyping may assist in identifying a subset of patients who could potentially benefit from immunomodulatory therapy; we assessed the relationship between the G-308A polymorphism of the TNF-? gene and changes in left ventricular (LV) chamber dimensions and systolic function in patients with idiopathic dilated cardiomyopathy (IDC) before and six months after diuretic; digoxin and angiotensin-converting enzyme inhibitor (ACEI) therapy. In 331 patients with IDC and 349 controls; the TNF-2 (A) allele (odds ratio = 1.509; 95CI = 1.130-2.015; p 0.01) and the TNF-12/22 (AG/GG) genotype (odds ratio CI = 1.159-2.266; p 0.01) were associated with IDC. However; in 122 patients with IDC; the TNF-? genotype was not associated with plasma TNF-? concentrations. In 133 patients with IDC; the TNF-? genotype failed to predict either the severity of pump dysfunction and cardiac dilatation at baseline; or changes in pump function and cardiac dimensions after six months of medical treatment. We conclude therefore that although the TNF-? gene G-308A polymorphism may contribute to the development of IDC; it does not influence pump function or adverse cardiac remodelling in patients with IDC. Genotyping for this variant is therefore unlikely to assist in identifying patients with heart failure who may be particularly susceptible to novel immunomodulatory therapeutic strategies

Screening cardiopharmacologique du desmodium velutinum (Willd) DC (papilionaceae)

Des extraits aqueux de feuilles et de racines du desmodium velutinum (Willd) DC ont ete testes sur le systeme cardio-vasculaire de differents animaux; apres une determination de la toxicite. Les resultats obtenus permettent d'affirmer des proprietes antihypertensive et cardiodepressive de ces produits

The pharmacological actions of a crude aqueous extract of khat (MIRAA) on rabbit's duodenum and heart in vitro

In this study a crude aqueous extract from fresh leaves and twigs of khat (Miraa) was investigated for its effects in vitro on rabbit's doudenum and perfused heart preparation. There was a significant reduction in spontaneous contraction of the duodenum in the presence of increasing doses of khat extracts. On the rabbit's heart; khat caused an inhibition of spontaneous contractions. It is therefore suggested that chronic habitual abuse of khat may predispose to gastrointestinal and cardiovascular problems in human subjects

Neuroleptanalgesia in anaemic patients undergoing surgery at Mulago hospital

It is concluded that NLA is a useful alternative to general anaesthesia; in whom depression of cardiovascular system and damage to the liver should be avoided

The cardiovascular physiology

This book is intended for undergraduates. It offers students a concise approach to circulation and cardiac function. It could be useful in eng courses for health personnel