Acute myocardial infarction (I21)

    • ICD-10 Index

      • Diseases of the circulatory system (I00–I99)

        • Ischemic heart diseases (I20-I25)

            • Acute myocardial infarction (I21)
            • I21 - Acute myocardial infarction NON-BILLABLE CODE
            • I21.0 - ST elevation (STEMI) myocardial infarction of anterior wall NON-BILLABLE CODE
            • I21.01 - STEMI involving left main coronary artery BILLABLE CODE
            • I21.02 - STEMI involving left anterior descending coronary artery BILLABLE CODE
            • I21.09 - STEMI involving oth coronary artery of anterior wall BILLABLE CODE
            • I21.1 - ST elevation (STEMI) myocardial infarction of inferior wall NON-BILLABLE CODE
            • I21.11 - STEMI involving right coronary artery BILLABLE CODE
            • I21.19 - STEMI involving oth coronary artery of inferior wall BILLABLE CODE
            • I21.2 - ST elevation (STEMI) myocardial infarction of other sites NON-BILLABLE CODE
            • I21.21 - STEMI involving left circumflex coronary artery BILLABLE CODE
            • I21.29 - STEMI involving oth sites BILLABLE CODE
            • I21.3 - ST elevation (STEMI) myocardial infarction of unsp site BILLABLE CODE
            • I21.4 - Non-ST elevation (NSTEMI) myocardial infarction BILLABLE CODE
            • I21.9 - Acute myocardial infarction, unspecified BILLABLE CODE
            • I21.A - Other type of myocardial infarction NON-BILLABLE CODE
            • I21.A1 - Myocardial infarction type 2 BILLABLE CODE
            • I21.A9 - Other myocardial infarction type BILLABLE CODE

Clinical Information for Acute myocardial infarction (I21)

Anterior Wall Myocardial Infarction - MYOCARDIAL INFARCTION in which the anterior wall of the heart is involved. Anterior wall myocardial infarction is often caused by occlusion of the left anterior descending coronary artery. It can be categorized as anteroseptal or anterolateral wall myocardial infarction.

Inferior Wall Myocardial Infarction - MYOCARDIAL INFARCTION in which the inferior wall of the heart is involved. It is often caused by occlusion of the right coronary artery.

Kounis Syndrome - A disorder of cardiac function secondary to hypersensitivity reactions. It is characterized by coexistence of acute coronary syndromes and cardiac MAST CELL and PLATELET ACTIVATION. It may be induced by exposure to drugs (e.g., antibiotics, anesthetics, contrast media), food, and environmental triggers (e.g., insect bites and stings, poison ivy).

MINOCA - Myocardial infarction in the absence of obstructive coronary artery disease. CORONARY CIRCULATION disruption is due to various other factors such as ATHEROSCLEROTIC PLAQUE and CORONARY VASOSPASM.

Myocardial Infarction - NECROSIS of the MYOCARDIUM caused by an obstruction of the blood supply to the heart (CORONARY CIRCULATION).

Non-ST Elevated Myocardial Infarction - A myocardial infarction that does not produce elevations in the ST segments of the ELECTROCARDIOGRAM. ST segment elevation of the ECG is often used in determining the treatment protocol (see also ST Elevation Myocardial Infarction).

Myocardial Ischemia - A disorder of cardiac function caused by insufficient blood flow to the muscle tissue of the heart. The decreased blood flow may be due to narrowing of the coronary arteries (CORONARY ARTERY DISEASE), to obstruction by a thrombus (CORONARY THROMBOSIS), or less commonly, to diffuse narrowing of arterioles and other small vessels within the heart. Severe interruption of the blood supply to the myocardial tissue may result in necrosis of cardiac muscle (MYOCARDIAL INFARCTION).

Instructional Notations

Includes Includes
This note appears immediately under a three character code title to further define, or give examples of, the content of the category.

  • cardiac infarction
  • coronary (artery) embolism
  • coronary (artery) occlusion
  • coronary (artery) rupture
  • coronary (artery) thrombosis
  • infarction of heart, myocardium, or ventricle
  • myocardial infarction specified as acute or with a stated duration of 4 weeks (28 days) or less from onset

Use Additional Code Use Additional Code
The “use additional code” indicates that a secondary code could be used to further specify the patient’s condition. This note is not mandatory and is only used if enough information is available to assign an additional code.

  • code, if applicable, to identify:
  • exposure to environmental tobacco smoke Z77.22
  • history of tobacco dependence Z87.891
  • occupational exposure to environmental tobacco smoke Z57.31
  • status post administration of tPA rtPA in a different facility within the last 24 hours prior to admission to current facility Z92.82
  • tobacco dependence F17
  • tobacco use Z72.0

Type 2 Excludes Type 2 Excludes
A type 2 excludes note represents "Not included here". An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.

  • old myocardial infarction I25.2
  • postmyocardial infarction syndrome I24.1
  • subsequent type 1 myocardial infarction I22