Which cardiac enzyme is involved in diagnosing myocardial infarction?

When diagnosing a myocardial infarction (MI), multiple cardiac enzymes can be involved in the process, each serving a specific role. Creatine Kinase (CK), Lactate Dehydrogenase (LDH), and Myoglobin are all substances that can increase in the blood following cardiac injury.

Creatine Kinase, particularly the CK-MB isoenzyme, is a well-established marker for heart muscle damage. Its levels rise within a few hours after the onset of chest pain in an MI and can remain elevated for up to three days, making it useful for diagnosing recent myocardial infarctions.

Lactate Dehydrogenase is another enzyme that can be used in assessing MI, although it's more commonly associated with tissue damage in general. Its elevation can indicate myocardial injury, though it is less specific to cardiac tissue than CK-MB.

Myoglobin, a protein released from injured muscle, including cardiac muscle, can also be an early marker for myocardial infarction. Myoglobin rises very quickly after tissue injury, often within the first few hours, but it is not specific to cardiac tissue, which limits its diagnostic utility in isolation.

Given that all three of these biomarkers can be utilized in the diagnosis of myocardial infarction, indicating different aspects and timing of tissue injury