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  3. I00–I99
  4. I20-I25
  5. Angina pectoris (I20)

Angina pectoris (I20)

ICD-10 codes I20 through I20.9 are specifically used to classify various types of angina pectoris, a condition characterized by chest pain due to reduced blood flow to the heart muscle.

The code I20 refers broadly to angina pectoris, while subcodes detail distinct clinical presentations. For example, I20.0 denotes unstable angina, often described with terms like impending infarction and refractory angina, which signals worsening chest pain needing urgent care. I20.1 covers angina with documented coronary artery spasms, also known as Prinzmetal angina or vasospasm. I20.81 is used for angina linked to microvascular dysfunction, frequently called cardiac syndrome X, affecting small heart vessels. Other subcodes, such as I20.89, describe stable or atypical angina types including exercise-induced or nocturnal angina. The I20.9 code is reserved for unspecified angina pectoris and includes synonyms like typical angina and ischemic chest pain. These codes help both medical professionals and coders accurately capture the specific angina condition for diagnosis and billing.

Instructional Notations

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 to identify:
  • exposure to environmental tobacco smoke Z77.22
  • history of tobacco dependence Z87.891
  • occupational exposure to environmental tobacco smoke Z57.31
  • tobacco dependence F17
  • tobacco use Z72.0

Type 1 Excludes

A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.

  • angina pectoris with atherosclerotic heart disease of native coronary arteries I25.1
  • atherosclerosis of coronary artery bypass grafts and coronary artery of transplanted heart with angina pectoris I25.7
  • postinfarction angina I23.7

Clinical Terms

The following clinical terms provide additional context, helping users better understand the clinical background and common associations for each diagnosis listed in this section. Including related terms alongside ICD-10-CM codes supports coders, billers, and healthcare professionals in improving accuracy, enhancing documentation, and facilitating research or patient education.

Angina Pectoris

The symptom of paroxysmal pain consequent to MYOCARDIAL ISCHEMIA usually of distinctive character, location and radiation. It is thought to be provoked by a transient stressful situation during which the oxygen requirements of the MYOCARDIUM exceed that supplied by the CORONARY CIRCULATION.

Angina Pectoris, Variant

A clinical syndrome characterized by the development of CHEST PAIN at rest with concomitant transient ST segment elevation in the ELECTROCARDIOGRAM, but with preserved exercise capacity.

Angina, Stable

Persistent and reproducible chest discomfort usually precipitated by a physical exertion that dissipates upon cessation of such an activity. The symptoms are manifestations of MYOCARDIAL ISCHEMIA.

Angina, Unstable

Precordial pain at rest, which may precede a MYOCARDIAL INFARCTION.

Microvascular Angina

ANGINA PECTORIS or angina-like chest pain with a normal coronary arteriogram and positive EXERCISE TEST. The cause of the syndrome is unknown. While its recognition is of clinical importance, its prognosis is excellent. (Braunwald, Heart Disease, 4th ed, p1346; Jablonski Dictionary of Syndromes & Eponymic Diseases, 2d ed). It is different from METABOLIC SYNDROME X, a syndrome characterized by INSULIN RESISTANCE and HYPERINSULINEMIA, that has increased risk for cardiovascular disease.

Myocardial Infarction

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

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).