Cardiac Biomarkers and ACS Overview

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Questions and Answers

Which cardiac biomarker is generally released first during a coronary event due to its smaller size?

Adenosine (correct)

Troponin I

BNP

CK-MB

What is a key feature of an ideal cardiac biomarker regarding its specificity?

Present in high amounts in all tissues

Levels rise uniformly in all medical conditions

High myocardium/serum ratio, not present in non-cardiac tissue (correct)

Detectable many hours after injury

Which characteristic of a cardiac biomarker allows for early detection of a cardiac event?

High sensitivity and early release after injury (correct)

Prolonged diagnostic time window

Low accuracy in various scenarios

Invasiveness during detection

Which biomarker is primarily associated with necrosis in myocardial tissue?

CK-MB Signup and view all the answers

What role does a cardiac biomarker play in risk stratification?

It helps in decision making for care level and interventions Signup and view all the answers

Which of the following statements regarding biochemical cardiac markers is correct?

Markers generally increase in a predictable pattern post-injury. Signup and view all the answers

What is a crucial requirement for the robustness of a cardiac biomarker?

Simple, rapid, and accurate detection that is inexpensive Signup and view all the answers

During which phase is the cardiac biomarker release first seen?

Some ischemia, some necrosis Signup and view all the answers

What best describes the utility of biomarkers during a chest pain assessment?

Assist in determining the appropriate level of care and management Signup and view all the answers

In the context of detection methods evolution for cardiac markers, which of the following was NOT previously used?

Procalcitonin assay Signup and view all the answers

What is the primary role of AST in the context of myocardial injury?

It reflects the extent of cardiac damage. Signup and view all the answers

Which statement about the timeline of AST levels after myocardial infarction (MI) is correct?

AST levels rise 6-8 hours after chest pain onset. Signup and view all the answers

Which of the following biomarkers is NOT primarily associated with myocardial injury?

BNP Signup and view all the answers

How long does it typically take for AST activities to fall back to normal range after an MI?

4 to 5 days Signup and view all the answers

What does a peak value of AST typically indicate after myocardial injury?

Severe cardiac damage. Signup and view all the answers

Which of these conditions can cause elevated AST levels aside from myocardial injury?

Liver disease Signup and view all the answers

What is the significance of small elevations in AST levels after myocardial injury?

They indicate a favorable prognosis. Signup and view all the answers

Which biomarker is known for its acute response as a sign of myocardial injury among the options?

cTn Signup and view all the answers

Which biomarker is primarily used for the diagnosis of recent cardiac muscle damage?

Cardiac troponin (cTn) Signup and view all the answers

What does the measurement of B-type natriuretic peptide (BNP) indicate?

The presence and severity of heart failure Signup and view all the answers

Which statement is correct regarding C-reactive protein (CRP)?

It assesses the risk of atherosclerotic cardiovascular disease (ASCVD). Signup and view all the answers

Which biomarker is associated with the risk assessment of atherosclerotic cardiovascular disease (ASCVD)?

Homocysteine (Hcy) Signup and view all the answers

Which of the following biomarkers provides information about damage to cardiac myocytes?

Cardiac troponin (cTn) Signup and view all the answers

Which statement about natriuretic peptides is true?

They reflect the severity of heart failure. Signup and view all the answers

What is one limitation of catheterization and angiography in diagnosing heart disease?

They do not assess the biology of plaque lesions. Signup and view all the answers

How do lesser amounts of myocardial damage affect ECG findings?

They may cause minimal or no ECG changes. Signup and view all the answers

Study Notes

Ideal Cardiac Biomarker

Should be specific to cardiac tissue and should be able to differentiate between the various types of cardiac pathologies
Should be sensitive enough to detect early and reversible cardiac events
Should be predictive of future cardiac events
Should be robust in terms of detection, diagnostic time window, and accessibility

Cardiac Biomarker Functions

Assist in diagnosis and determining level of care for patients with chest pain, suspected ACS, and acute heart failure exacerbations
Facilitate risk stratification

Metabolic Changes During a Coronary Event

Cardiac biomarker release occurs only after irreversible damage due to enzyme leakage

Release of Myocardial Cell Constituents

Metabolites leak first due to their smaller size, followed by enzymes

ACS Sequence and Timing

Plaque rupture initiates ACS
Ischemia markers rise during the initial phase of ACS, up to 12 hours
Necrosis markers rise in the later phase, between 12 and 24 hours
Cardiac dysfunction markers indicate the extent of damage and can be used for long-term monitoring

Evolution of Biochemical Cardiac Markers

The field of cardiac biomarker testing has evolved significantly, beginning with the use of AST in the 1950s
Newer tests, like troponin assays and BNP measurements, provide more sensitive and specific information
Electrocardiogram (ECG), catheterization and angiography, and imaging are used to diagnose heart disease, but they have limitations

Laboratory Diagnosis of Heart Disease

Cardiac biomarkers, like troponin, are measured to assess recent cardiac muscle damage
Different biomarkers are used to assess various aspects of heart disease:
- ASCVD Risk Assessment: Lipids, Homocysteine, and CRP
- Heart Failure Severity: BNP and NT-pro-BNP

Biomarkers of Myocardial Injury

Biomarkers are categorized based on the type of myocardial injury they reflect, ranging from reversible mild injury to necrosis

Transaminases

AST and ALT, also known as SGOT and SGPT, are transaminases found in various tissues, including the heart
While they can indicate myocardial injury, they have poor sensitivity and specificity due to their presence in other tissues
Transaminase levels rise sharply after an MI and peak 18-24 hours post-onset
Peak levels reflect the extent of cardiac damage, with higher increases associated with more severe infarcts

Transaminase Activities in Tissues

Transaminase activities are significantly higher in liver, smooth muscle, and skeletal muscle compared to serum
Transaminase levels return to normal within 4-5 days if there is no new infarct

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Description

This quiz covers the essential properties and functions of ideal cardiac biomarkers, focusing on their role in diagnosing acute coronary syndrome (ACS) and stratifying patient risk. It also delves into the metabolic changes and timing of biomarker release during cardiac events. Test your knowledge on these crucial cardiac health indicators.