I21.21
BillableSTEMI involving left circumflex coronary artery
ST elevation (STEMI) myocardial infarction involving left circumflex coronary artery
Coding Notes
Inclusion Terms
Alternative clinical terms for this condition
- ST elevation (STEMI) myocardial infarction involving oblique marginal coronary artery
Includes
Conditions included under this code
- 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
Excludes 2
Conditions not included here, but the patient may have both
- •certain conditions originating in the perinatal periodP04-P96
- •certain infectious and parasitic diseasesA00-B99
- •complications of pregnancy, childbirth and the puerperiumO9A)O00
- •congenital malformations, deformations, and chromosomal abnormalitiesQ00-Q99
- •endocrine, nutritional and metabolic diseasesE00-E88
- •injury, poisoning and certain other consequences of external causesS00-T88
- •neoplasmsC00-D49
- •symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classifiedR00-R94
- •systemic connective tissue disordersM30-M36
- •transient cerebral ischemic attacks and related syndromesG45
- •old myocardial infarctionI25.2
- •postmyocardial infarction syndromeI24.1
- •subsequent type 1 myocardial infarctionI22
Use Additional Code
Additional codes that should follow this code
- code, if applicable, to identify:
- •exposure to environmental tobacco smokeZ77.22
- •history of tobacco dependenceZ87.891
- •occupational exposure to environmental tobacco smokeZ57.31
- •status post administration of tPA (rtPA) in a different facility within the last 24 hours prior to admission to current facilityZ92.82
- •tobacco dependenceF17
- •tobacco useZ72.0
Code Also
A second code may be required; sequencing depends on circumstances
Related Codes(1)
Also Known As / Clinical Terms(40)
SNOMED CT
- Acute myocardial infarction due to occlusion of circumflex branch of left coronary artery896689003
- Acute ST segment elevation myocardial infarction due to occlusion of circumflex branch of left coronary artery896691006
- Acute STEMI (ST elevation myocardial infarction) due to occlusion of circumflex branch of left coronary artery896691006
- Acute ST segment elevation myocardial infarction due to distal left circumflex coronary artery occlusion44811000087108
- Acute ST segment elevation myocardial infarction due to occlusion of distal portion of circumflex branch of left coronary artery44811000087108
- Acute STEMI (ST elevation myocardial infarction) due to distal LCX (left circumflex coronary artery) occlusion44811000087108
- Acute ST segment elevation myocardial infarction due to mid left circumflex coronary artery occlusion44821000087100
- Acute ST segment elevation myocardial infarction due to occlusion of mid portion of circumflex branch of left coronary artery44821000087100
- Acute STEMI (ST elevation myocardial infarction) due to mid LCX (left circumflex coronary artery) occlusion44821000087100
- Acute ST segment elevation myocardial infarction due to obtuse marginal branch of left circumflex coronary artery occlusion44831000087103
- Acute ST segment elevation myocardial infarction due to occlusion of obtuse marginal branch of circumflex branch of left coronary artery44831000087103
- Acute STEMI (ST elevation myocardial infarction) due to OM (obtuse marginal) branch of LCX (left circumflex coronary artery) occlusion44831000087103
- Acute ST segment elevation myocardial infarction due to occlusion of posterior lateral branch of circumflex branch of left coronary artery44841000087109
- Acute ST segment elevation myocardial infarction due to posterolateral branch of left circumflex coronary artery occlusion44841000087109
- Acute STEMI (ST elevation myocardial infarction) due to PL (posterolateral) branch of LCX (left circumflex coronary artery) occlusion44841000087109
- Acute ST segment elevation myocardial infarction due to occlusion of proximal portion of circumflex branch of left coronary artery44851000087107
- Acute ST segment elevation myocardial infarction due to proximal left circumflex coronary artery occlusion44851000087107
- Acute STEMI (ST elevation myocardial infarction) due to proximal LCX (left circumflex coronary artery) occlusion44851000087107
UMLS
Clinical Terms
- Acute ST segment elevation myocardial infarction due to occlusion of obtuse marginal branch of circumflex branch of left coronary artery
- Acute STEMI (ST elevation myocardial infarction) due to OM (obtuse marginal) branch of LCX (left circumflex coronary artery) occlusion
- Acute STEMI (ST elevation myocardial infarction) due to mid LCX (left circumflex coronary artery) occlusion
- Acute ST segment elevation myocardial infarction due to proximal left circumflex coronary artery occlusion
- Acute STEMI (ST elevation myocardial infarction) due to distal LCX (left circumflex coronary artery) occlusion
- Acute ST segment elevation myocardial infarction due to occlusion of posterior lateral branch of circumflex branch of left coronary artery
- Acute ST segment elevation myocardial infarction due to occlusion of mid portion of circumflex branch of left coronary artery
- Acute STEMI (ST elevation myocardial infarction) due to PL (posterolateral) branch of LCX (left circumflex coronary artery) occlusion
- ST elevation (STEMI) myocardial infarction involving oblique marginal coronary artery
- Acute STEMI (ST elevation myocardial infarction) due to occlusion of circumflex branch of left coronary artery
- Acute ST segment elevation myocardial infarction due to distal left circumflex coronary artery occlusion
- Acute ST segment elevation myocardial infarction due to occlusion of distal portion of circumflex branch of left coronary artery
- Acute myocardial infarction due to occlusion of circumflex branch of left coronary artery
- Acute ST segment elevation myocardial infarction due to occlusion of proximal portion of circumflex branch of left coronary artery
- Acute ST segment elevation myocardial infarction due to posterolateral branch of left circumflex coronary artery occlusion
- Acute ST segment elevation myocardial infarction due to occlusion of circumflex branch of left coronary artery
- Acute ST segment elevation myocardial infarction due to mid left circumflex coronary artery occlusion
- Acute ST segment elevation myocardial infarction due to obtuse marginal branch of left circumflex coronary artery occlusion
- Acute STEMI (ST elevation myocardial infarction) due to proximal LCX (left circumflex coronary artery) occlusion
Frequently Asked Questions
What is the ICD-10 code for stemi involving left circumflex coronary artery?
The ICD-10-CM code for stemi involving left circumflex coronary artery is I21.21. The full clinical description is "ST elevation (STEMI) myocardial infarction involving left circumflex coronary artery". I21.21 is a billable/specific code that can be used on insurance claims and medical billing.
What does ICD-10 code I21.21 mean?
ICD-10-CM code I21.21 represents “ST elevation (STEMI) myocardial infarction involving left circumflex coronary artery”. It is classified under Chapter 9: Diseases of the Circulatory System and is a billable/specific code that can be used on a claim.
Is I21.21 a billable code?
Yes, I21.21 is a billable/specific ICD-10-CM code and can be used to indicate a diagnosis on a medical claim.
What chapter is I21.21 in?
I21.21 is in Chapter 9: Diseases of the Circulatory System (codes I00-I99).
Are additional codes required with I21.21?
Yes, when using I21.21, also report: 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).
What SNOMED CT codes does I21.21 map to?
I21.21 maps to 7 SNOMED CT concepts: 44811000087108, 44821000087100, 44831000087103, 896691006, 44841000087109, and 2 more. SNOMED CT is a clinical terminology used in electronic health records.
What are the UMLS CUIs for I21.21?
I21.21 is linked to 2 UMLS Concept Unique Identifiers: C2882108, C2882107. The UMLS (Unified Medical Language System) integrates multiple biomedical vocabularies maintained by the U.S. National Library of Medicine.
How does I21.21 relate to ICF functioning codes?
ICF (International Classification of Functioning, Disability and Health) codes describe how conditions like stemi involving left circumflex coronary artery affect a person's functioning — body functions, activities, participation, and environmental factors. AutoICD provides ICF Core Sets for 12+ conditions and can map clinical text to ICF categories automatically. Browse the ICF directory to explore functioning codes.
What is the ICD-11 equivalent of I21.21?
There is no direct ICD-11 mapping available for I21.21 in the WHO crosswalk tables. This may mean the concept is classified differently in ICD-11. Use the ICD-10 to ICD-11 converter to search for related codes.
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Includes SNOMED Clinical Terms® (SNOMED CT®) used by permission of SNOMED International. Includes content from the UMLS Metathesaurus, courtesy of the U.S. National Library of Medicine.