Cardiac Biomarkers Flashcards
What is Acute Coronary Syndrome (ACS)?
Acute heart condition due to coronary atherosclerosis complications, including unstable angina, NSTEMI, and STEMI.
What is the difference between ACS and MI?
Myocardial infarction (MI) is a type of ACS characterized by myocardial necrosis. ACS includes both MI and unstable angina.
What are the two types of MI?
NSTEMI (Non-ST Elevation MI) – No Q waves on ECG. STEMI (ST Elevation MI) – Q waves present on ECG.
Why do diabetic patients often not feel pain in an MI?
Due to autonomic neuropathy, which reduces pain sensation.
What are the three main cardiac biomarkers used in acute MI?
Troponin, Myoglobin, NT-proBNP.
When is Troponin (cTn) used?
Gold standard for MI diagnosis. Highly specific for cardiac muscle injury.
When is Myoglobin used?
Early biomarker (1st hour after pain) but low specificity (elevates in muscle injury).
When is NT-proBNP used?
For chronic heart failure (CHF) assessment and severity monitoring
Why is time important in MI diagnosis?
Cardiac muscle does not regenerate, so early intervention is crucial.
What is the main advantage of Myoglobin?
Early detection of MI (first hour).
What is the main disadvantage of Myoglobin?
Low specificity (also elevated in trauma, kidney disease, etc.).
How do Troponin and Myoglobin differ?
Troponin is highly specific for MI, while Myoglobin rises early but lacks specificity.
What is the role of BNP/NT-proBNP in heart failure?
BNP = Chronic heart failure biomarker. Higher BNP = Worse heart failure.
Why is ultra-sensitive Troponin (cTnUs) better than conventional Troponin?
Detects smaller variations, allowing for earlier MI diagnosis.
What is the first step when a patient presents with chest pain?
Interrogation – Ask when the pain started to assess muscle damage.
Why is knowing the time of pain onset important?
The earlier the intervention, the more myocardium can be saved.
What are the two types of Coronary Syndromes based on ECG?
ST-elevated (STEMI) vs Non-ST elevated (NSTEMI).
How do we classify an ST-positive or ST-negative MI in practice?
ST-positive = STEMI ST-negative = NSTEMI or Unstable Angina
What is the function of Troponin I & T in muscle contraction?
They regulate actin-myosin interaction, allowing cardiac muscle contraction.
What is the role of Creatine Kinase-MB (CK-MB)?
Rises in MI but less specific than Troponin.
What is the key marker for assessing necrosis size in MI?
Troponin levels correlate with infarct size.
When should we use BNP/NT-proBNP?
To assess heart failure severity and prognosis.
What is the main role of BNP in heart failure?
BNP is released when the heart is overstretched, promoting diuresis & vasodilation.
What are validated indications for BNP/NT-proBNP?
- Differentiate cardiac vs. pulmonary dyspnea
- Monitor heart failure progression
- Assess risk & treatment efficacy
Why are lower decision values important in troponin testing?
They increase sensitivity, improving early detection of MI.
Why is research on new biomarkers important?
To improve early diagnosis and treatment of cardiovascular diseases.
- A 65-year-old diabetic patient presents with mild fatigue but no chest pain. ECG shows ST elevation. Lab tests:
* Troponin T: 1.5 µg/L (elevated)
* Myoglobin: 80 µg/L (borderline high)
* NT-proBNP: 5000 pg/mL (high)
What is the diagnosis, and what steps should be taken?
Diagnosis: Silent MI (due to diabetes) with underlying heart failure.
Next steps:
* Urgent angiography
* Revascularization (PCI or thrombolysis)
* Monitor BNP for heart failure management
