EMC - Cardiologie-Angéiologie最新文献

Carotid stenoses are the most frequent lesions of the aortic arch. The development of noninvasive investigation techniques such as Duplex Scan, MRI and Angio-MRI allowed a better detection of such lesions. The improvement of anaesthetic techniques and the reproducibility of the surgical procedures have resulted in improved management and results. Advances in endovascular techniques have made such treatment commonly considered for proximal stenosis, whereas long-term benefits of endovascular treatment for carotid lesions remain to be demonstrated. The indications for the treatment of occlusive lesions of subclavian and vertebral arteries are now better identified.

Sudden death is defined as an unexpected death due to a cardiac cause, which occurs within one hour after the onset of symptoms. Autopsy can provide evidence for an undiagnosed cardiac dilated or hypertrophic cardiomyopathy. In case of negative autopsy, the most presumable cause remains a genetically-determined malignant primary ventricular arrhythmia. Rhythmic sudden cardiac death is most frequently due to a channel disease without any structural heart disease. Primary ventricular arrhythmias include long QT syndrome, Brugada syndrome, short QT syndrome and Polymorphic Ventricular Tachycardia. The diagnosis of such syndromes relies upon specific ECG anomalies, personal history of family members, and eventually the results of echocardiography and drug challenge. For some of these diseases, morbid genes have been identified; this makes possible the management of pre symptomatic or undiagnosed family members by specialized multidisciplinary teams. Rescued sudden death exposes to a high risk of recurrence. In such patients, the automatic implantable defibrillator has dramatically improved survival.

Antiarrhythmic drugs are useful to prevent recurrence of arrhythmias. Maintenance of sinus rhythm after cardioversion for atrial fabrillation is a main goal. In patients with recurrence of persistant atrial fibrillation, rate slowing medication is an alternative. Anticoagulant drugs are necessary to prevent thromboembolic complications. Non pharmacological approach, such as catether ablation or implantable cardiac defibrillator, is prefered in others arrhythmias. Radiofrequency ablation is the first choice therapy for isthmus-dependant atrial flutter and supraventricular tachycardia such as atrionodal reentries and accessory pathways. Ventricular arrhythmias are often associated with impaired left ventricular function. A precise evaluation of the causal cardiomyopathy (ischemic, dilated or hypertrophic) is required to propose the best strategy between medical regimen alone and implantation of a defibrillator. Combination of both reduces the numbers of inappropriate shocks. Some inherited arrhythmogenic diseases with structurally normal hearts, are at high risk of sudden death. Beta-blockers are indicated in long QT syndrome and catecholergic ventricular polymorphic tachycardia whereas implantable defibrillator is better to prevent sudden death in high risk patients with Brugada syndrome.

Buerger's disease or thromboangiitis obliterans is an inflammatory, segmental and occlusive disease that most commonly affects the small and medium-sized arteries and veins of limbs. The disease typically occurs in young male smokers. The cause is unknown; however tobacco consumption is central to the initiation and progress of the disease. Some immunological processes could be involved and recently, an impaired endothelium-dependent vasorelaxation has been observed. The diagnosis is based on exclusion of another vascular disease, on clinical features and on arteriography. Concomitant Raynaud's phenomenon, or digital arteriopathy, or superficial thrombosis may be arguments for a diagnosis of Buerger's disease. To date, no long-term pharmacological therapy has shown any efficacy and the only efficient strategy to prevent disease progression is complete smoking discontinuation.

Atherosclerosis is the leading cause of death in industrialized countries. It manifests as an arterial disease, involving a chronic inflammation related to the interaction between modified lipoproteins, inflammatory cells (macrophages and T lymphocytes) and cellular components of the arterial wall. This chronic inflammation leads to a reactional scarring process of the arterial wall, which involves the smooth muscle cells and the production of an extracellular matrix, resulting in the formation of complex lesions. Unfortunately, some of these arterial lesions are subject to complications. The rupture or erosion of a plaque followed by an arterial thrombosis results in the rapid obstruction of the vessel and the onset of major clinical events such as myocardial infarction or cerebral vascular events. However many patients remain asymptomatic. Epidemiologic studies have clearly demonstrated that adverse lifestyle changes accompanying industrialization and urbanization leading to the increase of cardiovascular diseases should not be considered inevitable.

Hemodialysis treatments necessitate three times a week a double access to the blood circulation of the patients, allowing for flow-rates above 350 ml/min. Apart from end-stage renal disease, similar vascular accesses may be necessary for treatment of different chronic diseases, especially in children. Microsurgical creation of a direct arteriovenous fistula results in the enlargement of a superficial vein which becomes routinely easy to puncture. It is the best long-term angio-access. In contrast, the placement of prosthetic arteriovenous grafts frequently results in the development of early stenoses at the venous anastomosis that will lead to acute thrombosis. Central venous catheters placed through the internal jugular vein are very useful in case of urgent need for dialysis, but they are prone to infection and they frequently cause central vein stenosis or thrombosis; such procedure should be avoided therefore, as much as possible. Currently, duplex-ultrasound and interventional radiology play a major role in the creation and maintenance of hemodialysis vascular access.

The limb lymphoedema is the principal lymphatic disorder. Treatment of lymphoedema is based upon complex decongestive physiotherapy, a therapy that includes two phases. The first which is intensive reduces the lymphoedema volume with daily low stretch bandages associated with manual lymph drainage. The second phase of the treatment consists in stabilizing the lymphoedema volume with regular self-bandaging and elastic compression garment. Management of limb lymphoedema includes practical advices, weight loss when necessary and skin care to avoid potential cutaneous infections. Reconstructive surgery is rarely used. Cutaneous resection is a useful tool in genital lymphoedemas. Regular and prolonged medical follow-up is required for this chronic disease to maintain the necessary motivation of the patient.

Chilblain is an erytrocyanosis lesion of the lower limb extremities, associated with pruritus and scraping when warming. This disorder is characterized by its occurrence after exposure to moderate damp cold, its regression in 2 or 3 weeks, and relapses during wintertime. More often it concerns slim young women, but can be seen at all ages, even in older men. Clinic appearance greatly varies. In 50% of the cases, mother heredity is observed; acroyanosis occurs in 45%, and Raynaud's disease in 32% of the cases. Chilblain is benign in 60% of the patients, disabling in 34%, and ulcerate in 7%. The biological, paraclinical investigations, the main differential diagnosis, the lupus erythematosus, and the therapeutic management are reviewed, according to the disease severity.

Arterial embolism of extremities results from the obstruction of the artery by a blood clot originating in the heart and travelling through the bloodstream. Rheumatismal causes have been progressively discarded drawing attention to atheromatosis. Apart from cardiac embolism, experience has shown the existence of emboli developing in other arteries and veins called paradoxical emboli. The aetiology of emboli has been supplemented by modern techniques, including the Holter electrocardiogram (ECG), transoesophageal echocardiography (TEE), computed tomography angiography (CTA) and magnetic resonance angiography (MRA). The role of arteriography is to be considered based on the degree of emergency and the condition of artery before blockage. Technology advances have also improved the treatment of emboli, together with the Forgarty's catheter which is still widely used aspiration thrombectomy can be achieved percutaneously. Catheter directed thrombolysis is another useful technique in the treatment of distal ischemia. However, in pathologic arteries, embolism often requires transluminal dilatation or by pass grafting. Nonetheless, the prognosis tends to remain severe due to a high risk of amputation and death related to the aetiology, terrain and other embolic localizations.