Archives des maladies du coeur et des vaisseaux
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In general, there are two types of right heart thrombi diagnosed by echocardiography: mobile and non-mobile thrombi, more often located in the atrium than in the ventricle and a potential source of pulmonary embolism. However, they differ in several points: clinical context, clinical and echocardiographic presentations, embolic potential, prognosis and treatment. The result of peripheral venous thrombosis, mobile thrombus it is usually diagnosed during echocardiographic investigation of pulmonary embolism. ⋯ It decreases or disappears with anticoagulant therapy and the outcome is usually good. The differential diagnosis between a mobile thrombus and a Chiari network, or between an adherent thrombus and a vegetation on a intracardiac pacing wire may be difficult and requires transoesophageal echocardiography. The investigation of pulmonary embolism requires systematic echocardiography, one of the objectives of which is to search for right sided thrombi.
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Transthoracic echocardiography rarely confirms a diagnosis of pulmonary embolism by visualizing a thrombus in the pulmonary artery or right heart chambers. However, easily observed morphological and Doppler abnormalities may result from acute pulmonary hypertension: dilatation of the right heart chambers, a very sensitive and reliable sign of severe pulmonary embolism when the ratio of the right/left ventricular dimension > 0.6: abnormal interventricular septal contraction, a very specific sign of massive pulmonary embolism, and increased systolic pulmonary artery pressure. ⋯ The investigation is rapid and can be carried out at the bedside, allowing confirmation of the diagnosis in two thirds of cases and the institution of thrombolytic or surgical therapy without the need for pulmonary angiography. Doppler echocardiography is also useful for following up the haemodynamic changes and the regression of acute cor pulmonale after thrombolysis.
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The prognosis of thromboembolic disease depends, to a large degree, on the deep venous thrombosis. It is located in the legs in nearly 80% of cases and proximal to the popliteal vein in one out of two patients. It is the cause of recurrence and at longer term, of post-thrombotic disease, the frequency of which contrasts with the rarity of chronic post-embolic cor pulmonale. ⋯ Conversely, distal deep vein thrombosis only requires heparin therapy. Interruption of the inferior vena cava is essential when embolism complicates well-treated deep vein thrombosis or when the thrombosis becomes more extensive despite effective treatment. It is also advisable when pulmonary sequellae are severe, long-term anticoagulant therapy is contra-indicated or when the aetiology of the thromboembolism cannot be determined.
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Arch Mal Coeur Vaiss · Aug 1995
Comparative Study[Hormonal contribution to short-term variability of blood pressure in a renovascular hypertension model].
Spectral analysis was recently chosen to characterize the fast oscillations depending on the autonomic nervous system. Humoral stimuli could impinge on low frequency (LF) domain of blood pressure (BP) since the time lag to humoral systems activation is larger. This study was designed to analyse LF components of short-term variability of BP of conscious rats in conditions where humoral systems were activated. ⋯ After the combined blockade, the LF component of SBP of the hypertensive rats was equivalent to that of the sham rats. Thus, an increase in the LF component of BP variability was observed in a model of hypertension where the BP is dependent upon humoral factors. The contribution of the renin-angiotensin and kallikrein-kinin systems in the slow fluctuations of BP was demonstrated using two specific antagonists losartan and Hoe 140.