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The widespread use of cardiac computed tomography and cardiac magnetic resonance imaging in patients undergoing echocardiography presents an opportunity to correlate the images side by side. Accordingly, the aim of this report is to review aspects of the standard echocardiographic examination alongside similarly oriented images from the two tomographic imaging modalities. It is hoped that this exercise will enhance understanding of the structures depicted by echocardiography as they relate to other structures in the thorax. In addition to reviewing basic cardiac anatomy, the authors take advantage of these correlations with computed tomography and cardiac magnetic resonance imaging to better understand the issue of foreshortening, a common pitfall in transthoracic echocardiography. The authors also highlight an important role that three-dimensional echocardiography can potentially play in the future, especially as advances in image processing permit higher fidelity multiplanar reconstruction images.

In a fair, infinite lottery, it is possible to conclude that drawing a number divisible by four is strictly less likely than drawing an even number; and, with apparently equal cogency, that drawing a number divisible by four is equally as likely as drawing an even number.

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.amjmed.2010.06.018 Byline: Matthew W. Parker, Murray A. Mittleman, Carol A. Waksmonski, Greg Sanders, Marilyn F. Riley, Pamela S. Douglas, Warren J. Manning Keywords: Aortic regurgitation; Echocardiography; Mitral regurgitation; Pulmonary artery hypertension; Survival Abstract: Outcomes data in patients with aortic regurgitation or mitral regurgitation have been limited to small series with generally Author Affiliation: Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Mass Article Note: (footnote) Funding: None., Conflict of Interest: None of the authors has any conflict of interest associated with the work presented in this manuscript., Authorship: All authors had access to the data and played a role in writing this manuscript.

Binding of proteins to heparan sulfate is driven predominantly by electrostatic interactions between positively charged amino acid residues in the protein and negatively charged sulfate groups located at various positions along the polysaccharide chain. Although many heparin/heparan-sulfate-binding proteins have been described, few exhibit preferential binding for heparan sulfates containing relatively rare 3-O-sulfated glucosamine residues. To expand the “3-O-sulfate proteome,” affinity matrices were created from Chinese hamster ovary (CHO) cell heparan sulfate engineered in vitrowith and without 3-O-sulfate groups. Fractionation of different animal sera yielded several proteins that bound specifically to columns containing 3-O-sulfated heparan sulfate modified by two members of the heparan sulfate 3-O-sulfotransferase superfamily, Hs3st1 and Hs3st2. Neuropilin-1 was analyzed in detail because it has been implicated in angiogenesis and axon guidance. We show that 3-O-sulfation enhanced the binding of neuropilin-1 to heparan sulfate immobilized on plastic plates and to heparan sulfate present on cultured cells. Chemoenzymatically synthesized 3-O-sulfated heparan sulfate dodecamers protected neuropilin-1 from thermal denaturation and inhibited neuropilin-1-dependent, semaphorin-3a-induced growth cone collapse of neurons derived from murine dorsal root ganglia. The effect of 3-O-sulfation was cell autonomous and specific to Hs3st2 based on collapse assays of neurons derived from Hs3st1- and Hs3st2-deficient mice. Finally, 3-O-sulfated heparan sulfate enhanced the inhibition of endothelial cell sprouting by exogenous heparan sulfate. These findings demonstrate a reliable method to identify members of the 3-O-sulfate proteome and that 3-O-sulfation of heparan sulfate can modulate axonal growth cone collapse and endothelial cell sprouting.

Stress-first approaches to myocardial perfusion imaging provide diagnostically and prognostically accurate perfusion data equivalent to a full rest-stress study, save time in the imaging laboratory, and reduce the radiation exposure to patients and laboratory staff. Converting a nuclear cardiology laboratory from a conventional rest-stress strategy to a stress-first approach involves challenges such as the need for attenuation correction, triage of patients to an appropriate protocol, real-time review of stress images, and consideration of differential reimbursement.

Anaphylaxis rarely manifests as a vasospastic acute coronary syndrome with or without the presence of underlying coronary artery disease. The variability in the underlying pathogenesis produces a wide clinical spectrum of this syndrome. We present three cases of anaphylactic acute coronary syndrome that display different clinical variants of this phenomenon. The main pathophysiological mechanism of the allergic anginal syndromes is the inflammatory mediators released during a hypersensitivity reaction triggered by food, insect bites, or drugs. It is important to appropriately recognize and treat Kounis syndrome in patients with exposure to a documented allergen.

BACKGROUND: Studies suggest outpatient treatment or early discharge of patients with acute pulmonary embolism (aPE) is reasonable for those deemed to be at low risk of early mortality. We sought to determine clinical prediction rule accuracy for identifying patients with aPE at low risk for mortality.

Positron emission tomography (PET) myocardial perfusion imaging (MPI) offers technical benefits compared with single photon emission computed tomography (SPECT) MPI, but there has been no systematic comparison of their diagnostic accuracy for coronary artery disease. We performed a bivariate meta-analysis of the published literature to compare the sensitivity and specificity of PET versus SPECT stress MPI for ≥50 stenosis of any epicardial coronary artery in patients with known or suspected coronary artery disease.

A probability distribution is regularif it does not assign probability zero to any possible event. Williamson (Analysis, 67, 173–180, 2007) argued that we should not require probabilities to be regular, for if we do, certain “isomorphic” physical events (infinite sequences of coin flip outcomes) must have different probabilities, which is implausible. His remarks suggest an assumption that chances are determined by intrinsic, qualitative circumstances. Weintraub (Analysis, 68, 247–250, 2008) responds that Williamson’s coin flip events differ in their inclusion relations to each other, or the inclusion relations between their times, and this can account for their differences in probability. Haverkamp and Schulz (Erkenntnis, 76, 395–402, 2012) rebut Weintraub, but their rebuttal fails because the events in their example are even less symmetric than Williamson’s. However, Weintraub’s argument also fails, for it ignores the distinction between intrinsic, qualitative differences and relations of time and bare identity. Weintraub could rescue her argument by claiming that the events differ in duration, under a non-standard and problematic conception of duration. However, we can modify Williamson’s example with Special Relativity so that there is no absolute inclusion relation between the times, and neither event has longer duration except relative to certain reference frames. Hence, Weintraub’s responses do not apply unless chance is observer-relative, which is also problematic. Finally, another symmetry argument defeats even the appeal to frame-dependent durations, for there the events have the same finite duration and are entirely disjoint, as are their respective times and places.

Doppler echocardiography, including the ratio of transmitral E to tissue Doppler e′ velocities (E/e′), is widely used to estimate mean left atrial pressure (mLAP). This method, however, has not been validated in patients with acute coronary syndromes.

Background:Little has been published on the practice of echocardiography (echo) in the United States. We used the Intersocietal Accreditation Commission-Echocardiography (IAC-Echo) applications database to describe the personnel in echo laboratories seeking accreditation.