2026 ICD-10-CM Diagnosis Code I21.9Acute myocardial infarction, unspecified

AHRQ’s CCSR groups this code into broader clinical categories.

• 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).

• Acute Myocardial Infarction by ECG Finding|ACUTE MYOCARDIAL INFARCTION|Acute Myocardial Infarction|Acute Myocardial Infarction by EKG Finding

  an electrocardiographic finding showing a current injury of the myocardium.

• Acute Myocardial Infarction

  necrosis of the myocardium, as a result of interruption of the blood supply to the area. it is characterized by a severe and rapid onset of symptoms that may include chest pain, often radiating to the left arm and left side of the neck, dyspnea, sweating, and palpitations.

• Acute Myocardial Infarction by ECG Finding|ACUTE MYOCARDIAL INFARCTION|Acute Myocardial Infarction|Acute Myocardial Infarction by EKG Finding

  an electrocardiographic finding showing a current of injury with st elevation. no specification is provided for localization. (cdisc)

• Acute Myocardial Infarction From PCI Complication Type|PCI Acute Angiographic Complication|PCI Acute Angiographic Complication|PCI Acute Angiographic Complication|PCIAAC|PCIAAC

  a description of the complications from a percutaneous coronary intervention procedure that lead to an acute myocardial ischemic event.

• Acute Myocardial Infarction Type|ACMITYPE|ACMITYPE

  a classification or description of the acute myocardial infarction.

• Death due to Acute Myocardial Infarction Related to COVID-19|Death due to acute MI

  death by any cardiovascular mechanism (e.g., arrhythmia, sudden death, heart failure (hf), stroke, pulmonary embolus, peripheral arterial disease) less than or equal to 30 days after a myocardial infarction (mi), related to the immediate consequences of the mi, such as progressive hf or recalcitrant arrhythmia in a patient with probable or confirmed acute covid-19.

• Coronary Artery Perforation

  a dissection that extends through the full thickness of the coronary arterial wall. (acc)

Heart Attack

Each year almost 800,000 Americans have a heart attack. A heart attack happens when blood flow to the heart suddenly becomes blocked. Without the blood coming in, the heart can't get oxygen. If not treated quickly, the heart muscle begins to die.

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