Academic emergency medicine : official journal of the Society for Academic Emergency Medicine
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Comparative Study
Early diagnostic efficiency of cardiac troponin I and Troponin T for acute myocardial infarction.
To compare the early diagnostic efficiency of the cardiac troponin I (cTn-I) level with that of the cardiac troponin T (cTn-T) level, as well as the creatine kinase (CK), CK-MB, and myoglobin levels, for acute myocardial infarction (AMI) in patients without an initially diagnostic ECG presenting to the ED within 24 hours of the onset of their symptoms. ⋯ cTn-I, CK-MB, and myoglobin are significantly more specific for AMI than are CK and cTn-T. Myoglobin is the biochemical marker having the highest combination of sensitivity, specificity, and negative predictive value for AMI within 2 hours of ED presentation. Neither cTn-I nor cTn-T offers significant advantages over myoglobin and CK-MB in the early (< or = 2 hours) initial screening for AMI. The cardiac troponins are of benefit in identifying AMI > or = 6 hours after presentation.
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To determine the value of tumor necrosis factor alpha (TNF) and interleukin 1 beta (IL1) levels in predicting Streptococcus pneumoniae bacteremia in nontoxic-appearing, febrile children who do not have a bacterial source for their fever on physical examination. ⋯ Like the WBC count, TNF and IL1 are good negative but poor positive predictors of Streptococcus pneumoniae bacteremia in nontoxic-appearing, febrile children. At present, the addition of plasma TNF or IL1 levels would add little to emergency physicians' ability to predict Streptococcus pneumoniae bacteremia. However, as the quantification of these cytokines becomes more rapid, available, and standardized, and more knowledge of TNF and IL1 levels during various illnesses is gained, their utility in the clinical setting for ruling out bacteremia should be further assessed.
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Case Reports
Left bundle branch block pattern complicating the electrocardiographic evaluation of acute myocardial infarction.
The ECG diagnosis of ischemic heart disease is made more difficult in the setting of left bundle branch block (LBBB). The ECG diagnosis of prior or remote myocardial infarction (MI) is extremely difficult in this setting. ⋯ Several strategies are available to the emergency physician (EP) to assist in the correct interpretation of this ECG pattern, including: a knowledge of the anticipated ST-segment--T-wave changes of LBBB and, consequently, the ability to recognize ischemic morphologies; the performance of serial ECGs demonstrating dynamic changes encountered in ischemic patients; and a comparison with previous ECGs. Three cases are reported in which an analysis of the 12-lead ECG in the setting of LBBB assisted the EP in establishing the correct diagnosis of acute MI and applying timely, appropriate therapy.