Assessment of acute myocardial infarction: current status and recommendations from the North American society for cardiovascular imaging and the European society of cardiac radiology

There are a number of imaging tests that are used in the setting of acute myocardial infarction and acute coronary syndrome. Each has their strengths and limitations. Experts from the European Society of Cardiac Radiology and the North American Society for Cardiovascular Imaging together with other prominent imagers reviewed the literature. It is clear that there is a definite role for imaging in these patients. While comparative accuracy, convenience and cost have largely guided test decisions in the past, the introduction of newer tests is being held to a higher standard which compares patient outcomes. Multicenter randomized comparative effectiveness trials with outcome measures are required

Physiologic Influences of Transepithelial K+ Secretion

Cellular ionic balance relies on ion channels and coupled transporters to maintain and use the transmembrane electrochemical gradients of the cations Na+ and K+. High intracellular K+ concentration provides a ready reserve within the body allowing epithelia to secrete K+into the fluid covering the apical membrane in the service of numerous physiologic activities. A major role for transepithelial K+ secretion concerns the balance of total body K+ such that excretion of excess K+ in the diet safeguards against disturbances to cellular balance. Accomplishing this transepithelial flow involves two archetypical cellular mechanisms, Na+ absorption and Clr secretion. Ion channels for K+, Na+, and Clr , as well as cotransporters, exchangers, and pumps contribute to produce transepithelial flow by coupling electrochemical gradients such that K+ flow enters across the basolateral membrane and exits through the apical membrane. Beyond excretion, transepithelial K+ secretion serves to create the high K+ concentration of endolymph in the inner ear that supports sensation of sound and body orientation. For several epithelia such as those in airways and gastric mucosa, the elevated K+ concentration of apical fluid may occur largely as a consequence of supporting the secretion of other ions such as Clr or H+. Less well-appreciated consequences of K+ secretion may result as in saliva and colonic luminal fluid where a high K+ concentration likely influences interactions with the resident microbiome. Independent control of K+ secretion also allows for specific adjustments in rate that serve the physiology of organs large and small