Cardiac markers

Diagnostika IM
The most serious type of ischemic injury is acute myocardial infarction. Transient and fully reversible myocardial ischemia is called angina pectoris. Clinical manifestations:
 * Pain in the chest
 * Changes on ECG
 * Changes in biochemical markers

New tests in the diagnosis of IM



 * Myoglobin
 * cytoplasmic protein, source of O2 in the anaerobic phase of contraction
 * in the blood 0.5-2 h after MI (sensitivity 4-5 h)
 * small molecule (Mr = 17,100), rapidly lost from the blood through the glomeruli
 * Standard
 * M < 92 µg/l
 * F < 76 µg/l


 * Izoenzyme CK-MB mass (antigen determination)
 * Concentration is given in mass units (µg/l) !!!
 * degraded molecules also react to the antigen (higher sensitivity)
 * standard: < 5 µg/l

Recommended procedure for biochemical examination in suspected AMI

 * First recruitment on admission - STATIM
 * Basic parameters for broader DD: Na, K, Cl, urea, creatinine, Ca, uric acid, cholesterol, TAG, total bilirubin, ALT, AST, ALP, GMT, LD, CRP
 * Cardiac markers:
 * CK, CK-MB
 * Myoglobin – difficulty lasting 2-12 hours, normal renal function
 * Troponin T:
 * a) within 8 hours to exclude AMI
 * b) after 12 hrs to diagnose microinfarcts


 * Further recruitment
 * 2. Recruitment in 6 ± 2 hours (CK, CK-MB, troponin T, Myoglobin)
 * 3. Recruitment in 12 ± 2 h (CK, CK-MB if the diagnosis or extent of involvement is not clear)
 * 4. Recruitment in 24 ± 2 h - exceptionally

Myoglobin

 * < 30 µg/l
 * normal in healthy subjects, between 6-10 h secreted by AMI


 * 30–70 µg/l
 * if concentration rises to less than 40 µg/l within 1 h, IM can be excluded


 * > 70 µg/l
 * if skeletal muscle damage is excluded, IM

Troponin T

 * < 0.05 µg/l - IM can be excluded, repeat in 10-12 h
 * 0.05-0.1 µg/l - repeat testing in 1 hour is recommended
 * 0.1-3 µg/l - myocardial damage
 * > 3 µg/l - massive myocardial damage

Troponin I

 * <0.1 µg/l - IM can be excluded
 * 0.6-1.5 µg/l - according to the WHO this is evidence of IM

Natriuretic peptides

 * Hormones synthesized in cardiomyocytes of the cardiac atria and ventricles
 * Maintain electrolyte and volume homeostasis
 * ANP, BNP - produced by cardiomyocytes
 * CNP - produced by endothelial cells of blood vessels and renal epithelium

Related articles

 * Cardiac markers
 * Cardiac markers in AMI