In this prospective multicenter trial of chest pain patients without known CAD, 64-multidetector row CCTA possesses high diagnostic accuracy for detection of obstructive coronary stenosis at both thresholds of 50% and 70% stenosis. Importantly, the 99% negative predictive value at the patient and vessel level establishes CCTA as an effective noninvasive alternative to ICA to rule out obstructive coronary artery stenosis. (A Study of Computed Tomography [CT] for Evaluation of Coronary Artery Blockages in Typical or Atypical Chest Pain; NCT00348569).

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We hypothesized that visual acuity in fishes and thus reactive distance should increase with fish size; visual acuity depends on eye lens diameter and cone density in the retina, and eye lens diameter increases with fish size. Though cone density declines in larger fish, we expected this effect to be relatively small. We tested this hypothesis for a behavioral measure of visual acuity, the reactive distance of bluegill (Lepomis macrochirus) sunfish to zooplankton prey, in aquaria (375 L) for fish from 27 to 162 mm standard length. Reactive distance increased nonlinearly with fish size; the rate of increase in reactive distance slows in larger fish. For fish of a given size, reactive distance was dependent on prey size, but visual angle measured from the fish eye was nearly constant. Whereas lens diameter and visual acuity increase with fish size in bluegills, the acuity of larger fish is less than expected from eye lens diameter alone. This is probably a result of cone density decreasing with fish size, as has been found for other fishes. The observed fish-size-dependent differences in reactive distance imply very large differences in visual volumes and encounter rates with prey among size-classes of bluegills. Habitat segregation among bluegill size-classes may prevent the intense intraspecific competition for prey that would be expected, in part, from the superior visual acuity of larger fish.Key words: foraging, reactive distance, size-class interactions, bluegill, Lepomis macrochirus; predation, visual acuity, zooplankton

The quality of acute chest pain related to cocaine use is indistinguishable from that experienced in acute myocardial ischemia. Abnormal or normal variant electrocardiographic findings are common in patients with chest pain related to cocaine use, but nevertheless the incidence of acute myocardial infarction is low. The ST-segment and T-wave changes can mimic acute myocardial injury and are most likely normal findings in young black men that can be readily recognized in the emergency department. Most of these patients do not require admission to an intensive care unit.

Perfusion imaging with Tc-99m-sestamibi can identify post-MI patients at hospital discharge in whom LV function is discordant with the measured infarct size. Patients with stunning have late increases in LVEF; patients with hyperkinesia have late decreases. This methodology, performed at discharge, is predictive of late changes in LV function.