infarction

DEFINITION of infarction

Infarction is the process by which a localized area of tissue undergoes irreversible necrosis (cell death) as a direct result of ischemia — the sustained deprivation of oxygenated blood supply sufficient to maintain cellular metabolism. It is distinguished from transient ischemia, in which blood flow is temporarily reduced but restored before permanent injury occurs, and from necrosis broadly, which may result from many causes beyond vascular occlusion. The underlying mechanism involves arterial or venous occlusion (thrombotic, embolic, vasospastic, or compressive), leading to ATP depletion, failure of ion pumps, cellular swelling, membrane rupture, and ultimately coagulative necrosis — the characteristic histologic pattern seen in most solid organ infarcts. Infarction may be physiological only in rare perinatal or involutional contexts (e.g., placental cotyledon infarcts); the vast majority of clinical infarcts are pathological. Clinically relevant subtypes include myocardial infarction (I21.9), cerebral infarction (I63.9), pulmonary infarction (I26.99), renal infarction (N28.0), intestinal infarction (K55.069), and splenic infarction (D73.5). It is commonly confused with ischemia (reversible oxygen deprivation without necrosis) and infarct (which refers to the resulting necrotic tissue zone itself, rather than the causative process).

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ETYMOLOGY of infarction

latin

Component	Origin	Meaning
in-	Latin in (in)	“into,” “within” — directional/intensifying prefix
farc-	Latin farcire (FAR-kee-reh), “to stuff, to cram"	"to stuff,” “to pack,” “to fill”
-tion	Latin -tio, -tionis (TEE-oh)	Noun-forming suffix — “act or process of”

The word entered English in the 1650s as infarction (noun), from Medieval Latin infarcire — literally “a stuffing into.” The term originally described tissue that appeared engorged or stuffed with blood (as in hemorrhagic infarcts), before the modern pathological meaning of ischemic necrosis became dominant. The root farcire (“to stuff”) connects infarction to the -farc- root family: infarct (in- + farc- → stuffed in, the necrotic tissue zone), farce (farcire → to stuff, originally a culinary/theatrical term for filling), and refection (re- + facere → to restore by filling). The directional prefix in- is highly productive in medical terminology: infarct, infiltrate, inflammation, incarceration, intussusception.

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🔀 ALIASES / ALTERNATE TERMS

• Infarcted (adjective form — appears in collocations such as “infarcted myocardium,” “infarcted bowel segment,” “infarcted renal cortex”)
• Infarct (the necrotic tissue zone produced by infarction; the noun referring to the lesion itself rather than the process — e.g., “a pale infarct of the spleen”)
• Ischemic necrosis (clinical synonym emphasizing the mechanism; used broadly across specialties; coded under site-specific categories)
• Coagulative necrosis (histopathologic synonym; the microscopic pattern characteristic of most solid-organ infarcts; distinguished from liquefactive necrosis seen in CNS infarcts)
• Pale infarct (anemic or white infarct; occurs in solid organs with end-arterial supply — heart, kidney, spleen; no collateral hemorrhage into necrotic zone)
• Red (hemorrhagic) infarct (occurs in organs with dual blood supply or loose tissue — lung, intestine, brain; blood re-enters necrotic zone from collaterals)
• Lacunar infarct (small deep cerebral infarct from lipohyalinosis of perforating arteries; coded under I63.81 or site-specific I63 subcategories)
• Watershed infarct (border-zone cerebral infarct between major arterial territories; typically from hypoperfusion rather than embolism)
• Embolic infarct (caused by thromboembolus, air embolus, fat embolus, or tumor embolus lodging in a vessel; etiologic subtype important for sequencing)
• Thrombotic infarct (caused by in-situ thrombus formation on atherosclerotic plaque; most common mechanism in MI and ischemic stroke)
• Venous infarct (caused by venous outflow obstruction rather than arterial occlusion; examples include mesenteric venous thrombosis K55.019 and cerebral venous sinus thrombosis I63.6)
• Septic infarct (infarct seeded with infectious organisms, as in endocarditis emboli; requires additional coding for the infectious etiology)

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🔗 RELATED TERMS

• Ischemia — the reversible precursor to infarction; defined as insufficient blood flow to meet tissue metabolic demands without yet causing irreversible cell death; distinguished from infarction by the absence of necrosis
• necrosis — shares the concept of cell death; infarction produces a specific subtype (coagulative necrosis in most solid organs; liquefactive in CNS); necrosis may arise from non-ischemic causes (toxins, infections, trauma)
• Thrombosis — the in-situ formation of a blood clot within a vessel; the most common proximate cause of myocardial and cerebral infarction; coded separately as the underlying condition when documented
• Embolism — migration of a thrombus, fat globule, air bubble, or tumor fragment that occludes a distal vessel; the dominant mechanism in pulmonary and many cerebral infarcts; requires coding for both the embolism and resultant infarct
• Atherosclerosis — the chronic plaque-forming disease of arterial walls that predisposes to thrombotic occlusion and infarction; underlying condition sequenced first when causal relationship is documented
• Reperfusion injury — paradoxical tissue damage that occurs when blood flow is restored to an ischemic zone; relevant in post-thrombolysis MI and stroke coding as a complication
• Apoptosis — programmed, regulated cell death; distinguished from the uncontrolled necrosis of infarction; relevant in understanding peri-infarct penumbra zone in cerebral infarction
• Myocardial infarction (MI) — infarction of cardiac muscle; the prototypical clinical form; STEMI (I21.0-I21.2x) vs. NSTEMI (I21.4) distinction critical for DRG assignment (MS-DRG 280-282)
• Cerebral infarction — infarction of brain parenchyma from arterial or venous occlusion or hypoperfusion; coded under I63.9 and subcategories; dominant diagnosis in stroke rehabilitation IRF admissions
• Pulmonary infarction — hemorrhagic infarction of lung tissue from pulmonary embolism; coded under I26.99 (PE without acute cor pulmonale) or I26.09 (with acute cor pulmonale)
• Renal infarction — ischemic necrosis of renal parenchyma from arterial embolism or thrombosis; coded under N28.0
• Echocardiography (TTE/TEE) — primary imaging modality for evaluating wall-motion abnormalities, ejection fraction, and mechanical complications of myocardial infarction

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CODING CORNER

🏥 ICD-10-CM CODES

Myocardial Infarction — STEMI (I21.0x-I21.2x | Site Required)

Code	Description
I21.01	ST elevation MI of anterior wall — left anterior descending
I21.02	ST elevation MI of anterior wall — other coronary artery
I21.09	ST elevation MI of anterior wall — unspecified
I21.11	ST elevation MI of inferior wall — right coronary artery
I21.19	ST elevation MI of inferior wall — other/unspecified
I21.21	ST elevation MI — left circumflex coronary artery
I21.29	ST elevation MI — other site
I21.3	ST elevation MI — unspecified site

Myocardial Infarction — NSTEMI / Subsequent / Complications

Code	Description
I21.4	Non-ST elevation myocardial infarction (NSTEMI)
I21.9	Acute myocardial infarction, unspecified
I21.A1	Myocardial infarction type 2
I21.A9	Other myocardial infarction type
I22.0	Subsequent STEMI of anterior wall
I22.1	Subsequent STEMI of inferior wall
I22.2	Subsequent non-ST elevation MI
I22.8	Subsequent STEMI of other site
I22.9	Subsequent STEMI, unspecified
I23.0	Hemopericardium as current complication of acute MI
I23.1	Atrial septal defect as current complication of acute MI
I23.2	Ventricular septal defect as current complication of acute MI
I23.3	Rupture of cardiac wall without hemopericardium
I23.4	Rupture of chordae tendineae as current complication
I23.5	Rupture of papillary muscle as current complication
I23.6	Thrombosis of atrium/ventricle as current complication
I23.7	Postinfarction angina
I23.8	Other current complications following acute MI

Cerebral Infarction (I63.x | Mechanism and Vessel Required)

Code	Description
I63.00	Cerebral infarction due to thrombosis of precerebral artery, unspecified
I63.011	Thrombosis of right vertebral artery
I63.012	Thrombosis of left vertebral artery
I63.019	Thrombosis of unspecified vertebral artery
I63.031	Thrombosis of right carotid artery
I63.032	Thrombosis of left carotid artery
I63.10	Cerebral infarction due to embolism of precerebral artery, unspecified
I63.111	Embolism of right vertebral artery
I63.112	Embolism of left vertebral artery
I63.131	Embolism of right carotid artery
I63.132	Embolism of left carotid artery
I63.20	Cerebral infarction due to unspecified occlusion of precerebral artery
I63.30	Cerebral infarction due to thrombosis of cerebral artery, unspecified
I63.311	Thrombosis of right middle cerebral artery
I63.312	Thrombosis of left middle cerebral artery
I63.321	Thrombosis of right anterior cerebral artery
I63.331	Thrombosis of right posterior cerebral artery
I63.40	Cerebral infarction due to embolism of cerebral artery, unspecified
I63.411	Embolism of right middle cerebral artery
I63.412	Embolism of left middle cerebral artery
I63.50	Cerebral infarction due to unspecified occlusion/stenosis of cerebral artery
I63.6	Cerebral infarction due to cerebral venous thrombosis
I63.81	Other cerebral infarction with right non-dominant side
I63.89	Other cerebral infarction
I63.9	Cerebral infarction, unspecified

Pulmonary, Renal, Intestinal, and Splenic Infarction

Code	Description
I26.01	Saddle embolus of pulmonary artery with acute cor pulmonale
I26.02	Saddle embolus of pulmonary artery without acute cor pulmonale
I26.09	Other PE with acute cor pulmonale
I26.90	PE without acute cor pulmonale, unspecified
I26.93	Single subsegmental PE without acute cor pulmonale
I26.94	Multiple subsegmental PE without acute cor pulmonale
I26.99	Other PE without acute cor pulmonale
N28.0	Infarction of kidney
K55.011	Focal acute infarction of small intestine
K55.012	Diffuse acute infarction of small intestine
K55.019	Acute infarction of small intestine, unspecified
K55.021	Focal acute infarction of large intestine
K55.022	Diffuse acute infarction of large intestine
K55.029	Acute infarction of large intestine, unspecified
K55.031	Focal acute infarction of small and large intestine
K55.039	Acute infarction of small and large intestine, unspecified
D73.5	Infarction of spleen

Old / Healed Myocardial Infarction and Chronic Forms

Code	Description
I25.2	Old myocardial infarction (healed MI; no current symptoms)
I25.5	Ischemic cardiomyopathy
I25.6	Silent myocardial ischemia
I25.700	Atherosclerosis of coronary artery bypass graft, unspecified

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🔧 COMMON CPT CODES (Infarction-Related Diagnosis & Treatment)

CPT Code	Description
93010	Electrocardiogram, interpretation and report only — primary screening tool for STEMI/NSTEMI identification
93000	Electrocardiogram with interpretation and report — routine/outpatient ECG
93306	Echocardiography, transthoracic (TTE), real-time with image documentation; complete; with spectral and color Doppler — primary modality for wall-motion assessment post-MI
93307	TTE, real-time with image documentation; complete; without Doppler
93308	TTE, follow-up or limited study
93312	Echocardiography, transesophageal (TEE), real-time with image documentation; including probe placement, image acquisition, interpretation
93454	Coronary angiography, catheter placement, imaging, supervision, interpretation; without left heart catheterization
93458	Left heart catheterization including coronary angiography
92928	Percutaneous transcatheter placement of intracoronary stent(s); single vessel
92929	Percutaneous transcatheter placement of intracoronary stent(s); each additional vessel
92941	Percutaneous transluminal revascularization of acute total/subtotal occlusion during acute MI — primary PCI
97110	Therapeutic exercises, 15 min — used in cardiac rehabilitation post-MI for strength and endurance
97530	Therapeutic activities, 15 min — functional activity restoration during cardiac rehab
93797	Physician services for outpatient cardiac rehabilitation without continuous ECG monitoring, per session
93798	Physician services for outpatient cardiac rehabilitation with continuous ECG monitoring, per session

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⚠️ Coding Note: When coding myocardial infarction, the STEMI vs. NSTEMI distinction (I21.0x-I21.3 vs. I21.4) is mandatory for both correct code assignment and accurate DRG assignment to MS-DRG 280, 281, or 282 — query the attending if only “acute MI” is documented without type specification. For cerebral infarction, the I63.x subcategory requires documentation of the underlying mechanism (thrombosis, embolism, unspecified occlusion, or venous) and the specific vessel affected; I63.9 is a common undercoding default — when imaging reports identify a specific vessel, that level of specificity should be reflected in the code. A high-value undercoding alert: I23.x complication codes (ventricular septal defect, papillary muscle rupture, hemopericardium) are frequently missed as additional diagnoses on acute MI admissions — review echo reports and cardiology notes for mechanical complications documentation. For inpatient sequencing, when a patient is admitted with an MI and undergoes PCI (92941), the MI code remains the principal diagnosis; subsequent MI (I22.x) codes within 28 days of a prior MI must be distinguished from a new acute event and coded accordingly. Payer-specific: UnitedHealthcare and Aetna replacement plans frequently require documentation of ejection fraction and Killip class for MI authorization and DRG validation on post-acute transfers.

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DERIVATIONS of infarction

TABLE definition AS Definition
FROM #medterm
WHERE length(filter(roots, (word) => econtains([[infarction]].roots, word))) > 0 AND file.name != [[infarction]].file.name
SORT file.name ASC

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Query functionality

TABLE definition AS Definition
FROM #medterm
WHERE length(filter(definition, (word) => econtains([[infarction]].definition, word))) > 0 AND file.name != [[infarction]].file.name

Med roots dictionary Appendix A Prefixes Appendix B Combining Forms Appendix C Suffixes Appendix D Suffix forms