ICD-10-CM Code I21.9

Acute myocardial infarction, unspecified

Version 2020 Billable Code

Valid for Submission

I21.9 is a billable code used to specify a medical diagnosis of acute myocardial infarction, unspecified. The code is valid for the year 2020 for the submission of HIPAA-covered transactions. The ICD-10-CM code I21.9 might also be used to specify conditions or terms like acute infarction of papillary muscle, acute myocardial infarction, acute myocardial infarction due to left coronary artery occlusion, acute myocardial infarction during procedure, acute myocardial infarction with rupture of ventricle, acute q wave myocardial infarction, etc

ICD-10:I21.9
Short Description:Acute myocardial infarction, unspecified
Long Description:Acute myocardial infarction, unspecified

Tabular List of Diseases and Injuries

The Tabular List of Diseases and Injuries is a list of ICD-10 codes, organized "head to toe" into chapters and sections with guidance for inclusions, exclusions, descriptions and more. The following references are applicable to the code I21.9:

Inclusion Terms

Inclusion Terms
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
  • Myocardial infarction (acute) NOS

Index to Diseases and Injuries

The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10 code(s). The following references for the code I21.9 are found in the index:


Synonyms

The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:

  • Acute infarction of papillary muscle
  • Acute myocardial infarction
  • Acute myocardial infarction due to left coronary artery occlusion
  • Acute myocardial infarction during procedure
  • Acute myocardial infarction with rupture of ventricle
  • Acute Q wave myocardial infarction
  • Aneurysm of coronary vessels
  • Aneurysm of coronary vessels
  • Coronary artery embolism
  • Coronary artery perforation
  • Coronary artery rupture
  • Drug-related myocardial necrosis syndrome
  • EKG: myocardial infarction
  • First myocardial infarction
  • Mitral valve regurgitation due to acute myocardial infarction with papillary muscle and chordal rupture
  • Mitral valve regurgitation due to acute myocardial infarction without papillary muscle and chordal rupture
  • Mitral valve regurgitation due to and following acute myocardial infarction
  • Mitral valve regurgitation due to and following acute myocardial infarction
  • Mixed myocardial ischemia and infarction
  • Mural thrombus of heart
  • Mural thrombus of right atrium
  • Myocardial infarction
  • Myocardial infarction in recovery phase
  • Myocardial infarction with complication
  • Myocardial ischemia
  • Myocardial necrosis
  • New myocardial infarction compared to prior study
  • Perforation of coronary artery co-occurrent and due to aneurysm of coronary artery
  • Pericarditis secondary to acute myocardial infarction
  • Pulmonary embolism due to and following acute myocardial infarction
  • Rupture of coronary artery co-occurrent and due to aneurysm of coronary artery
  • Thrombus of right atrium

Diagnostic Related Groups

The ICD-10 code I21.9 is grouped in the following groups for version MS-DRG V37.0 What are Diagnostic Related Groups?
The Diagnostic Related Groups (DRGs) are a patient classification scheme which provides a means of relating the type of patients a hospital treats. The DRGs divides all possible principal diagnoses into mutually exclusive principal diagnosis areas referred to as Major Diagnostic Categories (MDC).
applicable from 10/01/2020 through 09/30/2020.

  • 222 - CARDIAC DEFIBRILLATOR IMPLANT WITH CARDIAC CATHETERIZATION WITH AMI/HF/SHOCK WITH MCC
  • 223 - CARDIAC DEFIBRILLATOR IMPLANT WITH CARDIAC CATHETERIZATION WITH AMI/HF/SHOCK WITHOUT MCC

Replacement Code

I219 replaces the following previously assigned ICD-10 code(s):

  • I21.3 - ST elevation (STEMI) myocardial infarction of unsp site

Convert I21.9 to ICD-9

  • 410.90 - AMI NOS, unspecified (Approximate Flag)
  • 410.91 - AMI NOS, initial (Approximate Flag)
  • 410.92 - AMI NOS, subsequent (Approximate Flag)

Code Classification

  • Diseases of the circulatory system (I00–I99)
    • Ischemic heart diseases (I20-I25)
      • Acute myocardial infarction (I21)

Code History

  • FY 2018 - Code Added, effective from 10/1/2017 through 9/30/2018
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020

Information for Patients


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. But if you do get quick treatment, you may be able to prevent or limit damage to the heart muscle. That's why it's important to know the symptoms of a heart attack and call 911 if you or someone else is having them. You should call, even if you are not sure that it is a heart attack.

The most common symptoms in men and women are

  • Chest discomfort. It is often in center or left side of the chest. It usually lasts more than a few minutes. It may go away and come back. It can feel like pressure, squeezing, fullness, or pain. It also can feel like heartburn or indigestion.
  • Shortness of breath. Sometimes this is your only symptom. You may get it before or during the chest discomfort. It can happen when you are resting or doing a little bit of physical activity.
  • Discomfort in the upper body. You may feel pain or discomfort in one or both arms, the back, shoulders, neck, jaw, or upper part of the stomach.

You may also have other symptoms, such as nausea, vomiting, dizziness, and lightheadedness. You may break out in a cold sweat. Sometimes women will have different symptoms then men. For example, they are more likely to feel tired for no reason.

The most common cause of heart attacks is coronary artery disease (CAD). With CAD, there is a buildup of cholesterol and other material, called plaque, on their inner walls or the arteries. This is atherosclerosis. It can build up for years. Eventually an area of plaque can rupture (break open). A blood clot can form around the plaque and block the artery.

A less common cause of heart attack is a severe spasm (tightening) of a coronary artery. The spasm cuts off blood flow through the artery.

At the hospital, health care providers make a diagnosis based on your symptoms, blood tests, and different heart health tests. Treatments may include medicines and medical procedures such as coronary angioplasty. After a heart attack, cardiac rehabilitation and lifestyle changes can help you recover.

NIH: National Heart, Lung, and Blood Institute


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