Diagnosis of myocardial infarction

12 Lead EKG ST Elevation tracing color coded

Ha1

MI with contraction bands very high mag

Error creating thumbnail:

Gross pathology of a one week old myocardial infarction with focal rupture

Gross pathology of old myocardial infarction

Error creating thumbnail:

Histopathology of myofiber waviness in myocardial infarction

Diagnosis of myocardial infarction

The diagnosis of myocardial infarction (MI), commonly known as a heart attack, involves a combination of clinical evaluation, electrocardiogram (ECG) findings, and biomarker measurements. Myocardial infarction occurs when blood flow to a part of the heart is blocked for a long enough time that part of the heart muscle is damaged or dies.

Clinical Evaluation

The clinical evaluation begins with a thorough medical history and physical examination. Patients often present with chest pain or discomfort, which may radiate to the shoulder, arm, back, neck, or jaw. Other symptoms can include shortness of breath, nausea, vomiting, sweating, and lightheadedness.

Electrocardiogram (ECG)

An electrocardiogram is a critical tool in the diagnosis of myocardial infarction. It records the electrical activity of the heart and can show abnormalities that indicate an MI. The presence of ST-segment elevation, T-wave inversion, or pathological Q waves on the ECG can suggest myocardial infarction.

Biomarkers

Measurement of cardiac biomarkers in the blood is essential for confirming the diagnosis. The most commonly used biomarkers are troponin I and T, which are proteins released when the heart muscle is damaged. Elevated levels of these biomarkers are indicative of myocardial infarction. Other biomarkers that may be measured include creatine kinase-MB (CK-MB) and myoglobin.

Imaging

In some cases, additional imaging studies such as echocardiography, cardiac MRI, or coronary angiography may be used to assess the extent of heart damage and to identify blockages in the coronary arteries.

Differential Diagnosis

It is important to differentiate myocardial infarction from other conditions that can cause similar symptoms, such as angina, pericarditis, pulmonary embolism, and aortic dissection.

Related Pages

• Myocardial infarction
• Electrocardiogram
• Cardiac biomarkers
• Coronary artery disease
• Echocardiography
• Cardiac MRI
• Coronary angiography