Heart or lungs
Shortness of breath is a symptom that can be behind heart failure, lung disease, anemia, and obesity. It can be difficult to distinguish causes clinically, especially in older patients with multiple diseases. NT-proBNP solves this problem: it is produced by the ventricular myocardium during their stretching, and therefore increases specifically in heart failure. The key value is the high negative predictive ability: a normal level practically excludes heart failure as a cause of shortness of breath, and you need to look further in the lungs. The indicator is also used to assess severity and prognosis, to monitor therapy, and in cardio-oncology for early detection of cardiotoxicity of chemotherapy drugs. Levels naturally increase with age and with renal failure, which is taken into account when interpreting.
How to prepare to donate blood
- on an empty stomach 8–12 hours, you can drink water
- Eliminate alcohol and intense exercise per day
- no smoking in an hour
- donate blood before physiotherapy, x-rays and massage
- Take medications in advance by agreeing with your doctor
How to read the result
Reference values depend on the method and equipment of the laboratory, so it is correct to compare results only within the same laboratory. A deviation of a few percent from the normal limit in itself rarely matters - the overall picture and dynamics are important.
The analysis must be interpreted by a doctor: an isolated indicator without a clinical context is often misleading and leads to unnecessary examinations.