Levels of circulating procoagulant microparticles in nonvalvular atrial fibrillation.

Circulating procoagulant microparticles (MPs) arising from cell activation or fragmentation during apoptosis retain procoagulant properties and are increased in severe thrombotic states. We investigated whether circulating procoagulant MP levels would be increased in nonvalvular atrial fibrillation (AF). Using a hospital case-control study design, circulating procoagulant MP levels were measured in 45 patients with permanent and/or persistent AF who were not receiving anticoagulant therapy and 90 age-matched control subjects (45 with cardiovascular risk factors and 45 without). Annexin V-positive MP levels (expressed as nanomoles per liter of phosphatidylserine equivalent) were higher in patients with AF (median 9.3, interquartile range 6.8 to 17.3 nmol/L) than in control subjects with cardiovascular risk factors (median 4.9, interquartile range 3.7 to 8.4 nmol/L) and control subjects without cardiovascular risk factors (median 3.2, interquantile range 2.3 to 4.6 nmol/L; p<0.001). Platelet-derived MPs (captured with antiglycoprotein Ib) and endothelial-derived MPs (captured with anti-CD31) were similar in patients with AF and control subjects with cardiovascular risk factors but were significantly higher than in control subjects without cardiovascular risk factors. On multiple regression analysis, the presence of AF was a strong predictor of annexin V-positive MP level (p<.001). In conclusion, circulating procoagulant MPs are increased in persistent and/or permanent AF and might reflect a hypercoagulable state that could contribute to atrial thrombosis and thromboembolism.

[Cardiac involvement in hemochromatosis]. / Atteinte cardiaque de l'hémochromatose.

Cardiac involvement in hemochromatosis affects mainly the myocardium: iron overload of the myocytes reduces left ventricular distensibility. Heart failure is the most frequent manifestation of cardiac involvement. Diagnosis of cardiac involvement depends essentially on Doppler echocardiography showing abnormal left ventricular filling and, later, ventricular dilatation with left ventricular systolic dysfunction. Magnetic resonance imaging can quantify intrahepatic and intramyocardial iron levels. Age at onset of symptoms and specific organ involvement in hemochromatosis depend on the type of mutation. The two principal means of treatment by iron depletion are phlebotomy in primary hemochromatosis and excretion of iron by chemical chelation in secondary hemochromatosis. Early diagnosis and iron depletion improve survival by reducing organ iron overload, especially in the liver and the myocardium. Recent guidelines issued by Anaes (national agency for health evaluation) make it possible to identify risk factors for complications early, to determine disease stage, and to provide appropriate management as a function of disease severity.

Comparison of transesophageal echocardiographic identification of embolic risk markers in patients with lone versus non-lone atrial fibrillation.

Although transesophageal echocardiographically derived parameters, notably spontaneous echocardiographic contrast (SEC) in the left atrium or left atrial appendage (LAA), are known predictors of embolism in atrial fibrillation, their value is less well known in patients who have lone atrial fibrillation (LAF). This study describes transesophageal echocardiographic findings and identifies clinical predictors of SEC in the left atrium or LAA in a cohort of patients who had LAF. Eighty-two patients who had LAF and 289 patients who had non-LAF and underwent transesophageal echocardiography were enrolled from July 1998 to March 2002. LAA abnormality was defined as the presence of an LAA area >5 cm(2), emptying or filling LAA velocities <25 cm/s, or the presence of SEC or thrombus in the left atrium or LAA; LAA abnormalities were significantly less frequent in patients who had LAF than in those who had non-LAF. SEC in the left atrium or LAA was significantly less frequent in patients who had LAF than in those who had non-LAF (29.3% vs 49.8%, respectively, p <0.001). In patients who had LAF, SEC in the left atrium or LAA was significantly (p <0.05) less frequent in patients who were 60 years old (39.5%) and in patients who had paroxysmal LAF (5.9%) than in those who had persistent LAF (45.8%). On multivariate analysis, age and persistent LAF were the only clinical variables independently associated with SEC. Thus, transesophageal echocardiography detects thromboembolism risk markers in patients who have LAF. These abnormalities are less frequent in patients who have LAF than in those who are at low risk and have non-LAF; however, in patients who have LAF, older age and persistent atrial fibrillation are associated with these risk markers.

Is the aortic root dilated in obstructive sleep apnoea syndrome?

BACKGROUND: Obstructive sleep apnoea syndrome (OSAS) is associated with an increased risk of arterial hypertension (AH), coronary artery disease, atrial arrhythmias, heart failure, stroke and death. Whether OSAS influences aortic root size has not been fully investigated. The aim of our study was to investigate aortic root diameter and aortic stiffness in OSAS. METHODS: Using transthoracic Doppler echocardiography, we evaluated 76 patients with OSAS (mean age 52.7 +/- 9.5 years, 70 men [92%]) with no overt cardiovascular disease. The following parameters were measured offline: aortic diameter at Valsalva sinuses, aortic regurgitation (AR) grade, left ventricular (LV) mass, LV ejection fraction (LVEF, Simpson rule), systolic pulmonary artery pressure (sPAP). Aortic stiffness (carotid-femoral pulse wave velocity, PWV) was measured non-invasively using SphygmoCor technology. RESULTS: Mean duration of OSAS was four years and 84% of patients were being treated with continuous positive airway pressure. AH was documented in 39 (51%) patients. The mean aortic root diameter was 35.3 +/- 3.8 mm (26.9-44.6 mm) and the prevalence of aortic root dilatation was 3.9% (3 of 76 patients). On univariate analysis, age and sex were significant predictors of aortic root dilatation whereas arterial hypertension was not. CONCLUSIONS: The prevalence of aortic root enlargement was not increased in OSAS. Only age and sex and not arterial hypertension, were associated with aortic dilatation.