Right atrial thromboemboli: Clinical, echocardiography and pathophysiologic manifestations

In six patients with clinically unsuspected right atrial thromboemboli the diagnosis was made with two-dimensional echocardiography. Five patients had pulmonary emboli, and one had systemic embolization. Three patients had congestive cardiomyopathy, two with tricuspid regurgitation; of the remaining three, one had cor pulmonale complicated by tricuspid regurgitation, one had thrombophlebitis and one had no discernible cardiac illness. Four patients had dizziness or syncope, four had dyspnea, three had chest pain, three had hypotension and two had cyanosis. Five patients were treated with thrombolytic or anticoagulant therapy, or a combination of the two. In three patients, surgical removal of the thrombus was undertaken because of recurrent pulmonary emboli or tricuspid regurgitation, or both, and progressive right heart failure. The thromboemboli were removed in all three, but one patient died.On two-dimensional echocardiography, four of the six patients' thromboemboli were snake-like, unattached to the right atrium and prolapsed freely across the tricuspid valve into the right ventricle in diastole and back into the right atrium in systole. The other two patients' thromboemboli were attached to the right atrium and did not prolapse across the tricuspid valve.Our cases, together with a review of other reports, suggest that right atrial thromboemboli: 1) can be accurately diagnosed by two-dimensional echocardiography; and 2) result from two different pathophysiologic mechanisms developing a) in situ, either on a foreign body or secondary to reduced cardiac output, or b) as a result of an embolus from systemic vein thromboses

The youngest massive protostars in the Large Magellanic Cloud

We demonstrate the unique capabilities of Herschel to study very young luminous extragalactic young stellar objects (YSOs) by analyzing a central strip of the Large Magellanic Cloud obtained through the HERITAGE Science Demonstration Program. We combine PACS 100 and 160, and SPIRE 250, 350, and 500 microns photometry with 2MASS (1.25-2.17 microns) and Spitzer IRAC and MIPS (3.6-70 microns) to construct complete spectral energy distributions (SEDs) of compact sources. From these, we identify 207 candidate embedded YSOs in the observed region, ~40% never-before identified. We discuss their position in far-infrared color-magnitude space, comparing with previously studied, spectroscopically confirmed YSOs and maser emission. All have red colors indicating massive cool envelopes and great youth. We analyze four example YSOs, determining their physical properties by fitting their SEDs with radiative transfer models. Fitting full SEDs including the Herschel data requires us to increase the size and mass of envelopes included in the models. This implies higher accretion rates (greater than or equal to 0.0001 M_sun/yr), in agreement with previous outflow studies of high-mass protostars. Our results show that Herschel provides reliable longwave SEDs of large samples of high-mass YSOs; discovers the youngest YSOs whose SEDs peak in Herschel bands; and constrains the physical properties and evolutionary stages of YSOs more precisely than was previously possible.Comment: Main text: 4 pages, 3 figures, 1 table; Online material: 3 figures, 1 table; to appear in the A&A Herschel Special Issu