Cardiac Biomarkers
These are the blood tests used when the question is whether the heart muscle has been injured, or whether breathlessness is coming from the heart. They are hospital tests, and they are interpreted alongside the ECG and the story — never alone.
This is an educational reading aid, not a diagnosis and not medical advice. Reference ranges differ between laboratories — always read the range printed on your own report. Nothing here can see you, your history or your medicines. Do not start, stop or change any treatment on the strength of this page: take your report to a qualified doctor.
Reference ranges reviewed by Dr. Mohan Gayenlast reviewed
Your values
Fill in only the ones on your report. Anything you leave blank is simply skipped.
Released by a stretched, strained heart. Used mainly to rule heart failure OUT.
The other half of the same molecule, and the more commonly measured of the two.
The heart fraction of creatine kinase. Largely superseded by troponin.
Enter one or more values and your reading will appear here.
What this panel is easy to get wrong
- CHEST PAIN IS AN EMERGENCY, NOT A LOOK-IT-UP. If you have chest pain, pressure or tightness — especially with breathlessness, sweating, nausea, or pain spreading to the arm, neck or jaw — call emergency services now. Do not wait for a blood test and do not drive yourself.
- TROPONIN VALUES CANNOT BE COMPARED BETWEEN LABORATORIES. High-sensitivity assays report in ng/L and ordinary assays in ng/mL — a thousand-fold difference in units. Always read the range printed on your own report.
- A raised troponin means heart muscle injury, NOT necessarily a heart attack. Kidney failure, sepsis, heart failure, fast rhythms and pulmonary embolism all raise it.
- It is the CHANGE across two samples a few hours apart, more than any single value, that a doctor uses to decide.
Where these ranges come from: Troponin thresholds are ASSAY-SPECIFIC: every laboratory publishes its own 99th-percentile upper reference limit. The bands below are indicative only. Natriuretic peptide cut-offs follow widely used heart-failure rule-out values.
Where this is written from: This site is written from Indian clinical practice. Drug availability and brand names, vaccination schedules, national health programmes and some reference cut-offs differ between countries — a schedule or a threshold that is standard here may not be standard where you are. If you are reading outside India, check anything on this page against your own country’s guidance before you act on it.
Share this page
Troponin, CK-MB and the natriuretic peptides.