Code Acute Myocardial Infarction

Put your diagnosis coding skills to the test with this ED patient encounter.


HISTORY OF PRESENT ILLNESS: The patient is a 40-year-old male with a past medical history significant for hyperlipidemia and coronary artery disease who presents with a chief complaint of chest pain. He states that the chest pain started yesterday evening and it is intermittent; it comes and goes. The most recent episode of pain has lasted one hour. The severity of the pain has progressively increased, and he now ranks it as a seven on a scale of one to 10. He describes the pain as an uncomfortable pressure and squeezing pain that radiates to his neck and left arm. The patient states the pain is worse with walking and typically improves and resolves with rest. Changes in positioning do not affect the pain.

He reports associated shortness of breath and diaphoresis. The patient states that he has been nauseated and has had three episodes of vomiting since last night. He denies any fever or chills.

The patient denies any history of prior heart attack or stroke. He states he has not had recent surgery, trauma, or abnormal bleeding such as blood in urine or stool or nosebleed.

SOCIAL HISTORY: Denies alcohol and drug use. Smokes two packs of cigarettes per day. Works as a banker and admits to being very sedentary.

FAMILY HISTORY: Coronary artery disease (CAD) in father and brother


ALLERGIES: Penicillin

REVIEW OF SYSTEMS: As per HPI. All other systems reviewed and are negative.

PHYSICAL EXAM: Vitals – BP: 152/95, HR: 123, RR: 20, O2 sat: 91% on room air

General: Patient is awake, alert, and oriented to person, place, and circumstance. BMI 37.2. He appears in moderate discomfort but there is no evidence of distress. The patient ambulates without gait abnormality or difficulty.

HEENT: Normocephalic/atraumatic. Pupils are equal, round, and reactive to light bilaterally. Extraocular muscles are intact bilaterally. External auditory canals are clear bilaterally. Tympanic membranes are clear and intact bilaterally. Pharynx is clear, no erythema, exudates, or tonsillar enlargement.

Neck: No JVD. Neck is supple. There is free range of motion and no tenderness, thyromegaly, or lymphadenopathy noted.

Chest: No chest wall tenderness to palpation. Heart – tachy, regular rhythm; no murmurs, gallops, or rubs. Normal PMI. Lungs – clear to auscultation bilaterally.

Abdomen: Soft, non-distended, non-tender. No CVAT.

Skin: Warm, diaphoretic, mucous membranes moist, normal turgor, no rash noted.

Extremities: No gross visible deformity, free range of motion. No edema or cyanosis. No calf/ thigh tenderness or swelling.


The patient’s chest pain improved after sublingual nitroglycerine; nitroglycerine drip started at 30 ug/min.

10:40 p.m.: Cardiologist contacted. She agrees with intravenous nitroglycerin drip and tissue plasminogen activator (tPA) per 90-minute protocol. She is to come see patient in the emergency department.

10:45 p.m.: Risks and benefits of tPA discussed with patient and his family. They agree with administration of tPA and are willing to accept the risks.

10:50 p.m.: tPA started.

DIAGNOSTIC STUDIES: CBC and CMP were wnl; troponin I: 2.5 ng/mL, CK-MB 7.3 ng/mL

CXR: The lungs are clear, with no masses, nodules, consolidation or collapse visible. The heart is not enlarged, and the cardiac and mediastinal contours are normal. Both hemidiaphragms and the costophrenic angles are clearly demarcated. There is no abnormality of the imaged soft tissues or skeleton.

EKG: Sinus rhythm at 132 bpm, acute ischemic changes noted in inferior leads – ST elevation in leads III and aVF.

TREATMENT: Heparin lock x 2. Nasal cannula oxygen 3 liters/minute. Aspirin 325 mg. Nitroglycerin drip at 30 ug/min. Continuous cardiac monitoring. tPA 90-minute protocol. Heparin IV 5000-unit bolus followed by 1000 units/hour.

ASSESSMENT: Acute transmural myocardial infarction of inferior wall in patient with history of nicotine dependence and a family history of CAD.

PLAN: Patient admitted to cardiac care unit under the care of Dr. Jones.

Code the Diagnosis

ICD-10-CM codes:

I21.19   ST elevation (STEMI) myocardial infarction involving other coronary artery of inferior wall  

F17.210 Nicotine dependence, cigarettes, uncomplicated

Z82.49   Family history of ischemic heart disease and other diseases of the circulatory system

Rationale: The ICD-10-CM codes for myocardial infarction (MI) identify the site, temporal parameter (initial or subsequent), and whether the MI is an ST elevation or non-ST elevation infarction. In this example, the documentation states the patient is having an acute transmural myocardial infarction of the inferior wall. This designation is supported by the fact that the patient is presenting within four weeks of onset and has not had a previous MI. According to the EKG, the MI is further identified as an ST elevation MI (STEMI) with acute ischemic changes noted in the inferior leads.

The ICD-10-CM Tabular List instructs you to use an additional code to identify tobacco dependence. The social history indicates that the patient is a current cigarette smoker at two packs per day and tobacco dependence is documented. A family history of coronary artery disease is noted and should also be reported as the patient is diagnosed with an MI.


2021 ICD-10-CM code book

2021 ICD-10-CM Official Guidelines for Coding and Reporting

Latest posts by Stacy Chaplain (see all)
Translate »
%d bloggers like this: