BACKGROUND Between-assay comparability of 99th percentiles for cardiac troponin concentrations has not been assessed systematically in a single population for a large number of assays. METHODS We determined 99th percentiles for 19 cardiac troponin assays in heparin plasma samples from a population of 272 and 252 presumably healthy males and females, respectively. The assays evaluated included...

Background In reperfused ST-segment elevation myocardial infarction (STEMI), CMR late gadolinium enhancement (LGE) is the gold-standard for quantifying myocardial infarct (MI) size. Serum cardiac biomarker area-under-the-curve (AUC) is also used (CK-MB, Troponin T and I) and is more widely available than CMR. However, whether acute MI size measured by the 5 generation high-sensitivity Troponin ...

BACKGROUND Critically ill adults admitted for noncardiac conditions are at risk for acute myocardial ischemia. OBJECTIVES To detect myocardial ischemia and injury in patients admitted for noncardiac conditions and to examine the relationship of myocardial ischemia, injury, and acuity to cardiac events. METHODS Transient myocardial ischemia, acuity, elevations in serum troponin I, and in-hos...

to improve the specificity of biochemical markers of myocardial infarction (mi) a method to measure cardiac troponin-i (ctn-i) was developed. ctn-i is a protein unique to cardiac muscle and is released after mi. consecutive 150 patients admitted to the coronary care unit was studied. value of ctn-i was determined in all samples. ctn-i concentration in the mi patients group was increased compare...

background: the cardioprotective effect of ischemic preconditioning has been known for many years. since the temporary ischemia in the heart may cause lethal cardiac effects, the idea of creating ischemia in organs far from the heart such as limbs was raised as remote ischemic preconditioning (ripc). we hypothesized that the extension of ripc has more cardioprotective effect in patients undergo...

A 49-year-old female was referred to our hospital due to high serum creatine kinase (CK) (2,605 IU/L) and serum cardiac troponin T (cTnT) (0.342 ng/mL) levels. She had no other complaints and further examinations suggested no signs of cardiac disease. Additionally, the serum cardiac troponin I (cTnI) levels were normal. She reported having gradually felt difficulty in walking upstairs. A biopsy...

Conformational exchange has been demonstrated within the regulatory domain of calcium-saturated cardiac troponin C when bound to the NH2-terminal domain of cardiac troponin I-(1-80), and cardiac troponin I-(1-80)DD, having serine residues 23 and 24 mutated to aspartate to mimic the phosphorylated form of the protein. Binding of cardiac troponin I-(1-80) decreases conformational exchange for res...

OBJECTIVES Exercise leads to an increase in cardiac troponin I in healthy, asymptomatic athletes after a marathon. Previous studies revealed single factors to relate to post-race cardiac troponin I levels. Integrating these factors into our study, we aimed to identify independent predictors for the exercise-induced cardiac troponin I release. DESIGN Observational study. METHODS Ninety-two p...

BACKGROUND Cardiac troponin provides diagnostic and prognostic information in acute coronary syndromes, but its role in acute decompensated heart failure is unclear. The purpose of our study was to describe the association between elevated cardiac troponin levels and adverse events in hospitalized patients with acute decompensated heart failure. METHODS We analyzed hospitalizations for acute ...

The cardiac isoform of troponin I (cTnI) has a unique 31-residue N-terminal region that binds cardiac troponin C (cTnC) to increase the calcium sensitivity of the sarcomere. The interaction can be abolished by cTnI phosphorylation at Ser22 and Ser23, an important mechanism for regulating cardiac contractility. cTnC contains two EF-hand domains (the N and C domain of cTnC, cNTnC and cCTnC) conne...