Decoding Cardiac Diagnosis Codes: Your Comprehensive Guide to ICD-10 for Cardiology

Navigating the complexities of medical coding is crucial in healthcare, particularly in specialized fields like cardiology. Accurate coding ensures proper documentation, billing, and data analysis, all of which are essential for effective patient care and healthcare administration. In cardiology, the International Classification of Diseases, Tenth Revision (ICD-10) system plays a pivotal role. This guide serves as your go-to resource for understanding and utilizing common Cardiac Diagnosis Codes within the ICD-10 framework. Whether you’re a seasoned medical coder, a healthcare professional, or new to the field, this article will enhance your understanding of these vital codes.

Heart Rhythm Abnormalities: ICD-10 Codes Explained

Heart rhythm abnormalities, also known as arrhythmias, encompass a wide range of conditions where the heart beats too fast, too slow, or irregularly. Accurate diagnosis and coding are crucial for managing these conditions effectively. Here are common ICD-10 codes associated with heart rhythm abnormalities:

(ICD-9-CM 427.81, 427.89, 785.0, 785.1, 785.3)
R00.0 – Tachycardia, unspecified (This code is used when the heart rate is abnormally fast, but the specific type of tachycardia is not specified.)
R00.1 – Bradycardia, unspecified (This code is used when the heart rate is abnormally slow, without further specification.)
R00.2 – Palpitations (This code describes the subjective sensation of feeling one’s own heart beat, often described as fluttering or racing.)
R00.8 – Other abnormalities of heart beat (This category includes less common heart rhythm irregularities that don’t fit into the other R00.- categories.)
R00.9* – Unspecified abnormalities of heart beat (Use this code when a heart rhythm abnormality is noted, but not further defined.)

Atrial Fibrillation and Flutter: Essential ICD-10 Diagnosis Codes

Atrial fibrillation (AFib) and atrial flutter are common arrhythmias originating in the atria, the upper chambers of the heart. They are characterized by rapid and irregular heartbeats, increasing the risk of stroke and other complications. Precise coding is essential for tracking and managing these conditions.

(ICD-9-CM 427.31, 427.32)
I48.0 – Paroxysmal atrial fibrillation (This refers to AFib that starts and stops spontaneously, usually within 7 days.)
I48.1 – Persistent atrial fibrillation (Persistent AFib lasts longer than 7 days and may require intervention to restore normal rhythm.)
I48.2 – Chronic atrial fibrillation (Chronic AFib is continuous and long-lasting, often considered permanent.)
I48.3 – Typical atrial flutter (Typical atrial flutter is a more organized rhythm than AFib, often treatable with ablation.)
I48.4 – Atypical atrial flutter (Atypical atrial flutter is less organized and can be more challenging to treat than typical flutter.)
I48.91* – Unspecified atrial fibrillation (Use this code when atrial fibrillation is diagnosed, but the type – paroxysmal, persistent, or chronic – is not specified.)
I48.92* – Unspecified atrial flutter (This code is used when atrial flutter is diagnosed, but whether it’s typical or atypical is not documented.)

Other Cardiac Arrhythmias: A Spectrum of ICD-10 Codes

Beyond atrial fibrillation and flutter, a range of other cardiac arrhythmias require accurate ICD-10 coding. These can involve different parts of the heart and have varying degrees of severity.

(ICD-9-CM 427.41, 427.42, 427.60, 427.61, 427.69, 427.81, 427.89, 427.9)
I49.01 – Ventricular fibrillation (VFib) (A life-threatening arrhythmia where the ventricles quiver instead of pumping effectively, requiring immediate intervention.)
I49.02 – Ventricular flutter (Ventricular flutter is a very rapid, but more organized ventricular rhythm than VFib, also a serious condition.)
I49.1 – Atrial premature depolarization (APC) (Also known as premature atrial contractions, these are extra heartbeats originating in the atria.)
I49.2 – Junctional premature depolarization (JPC) (Premature beats originating from the AV junction, the area between the atria and ventricles.)
I49.3 – Ventricular premature depolarization (VPC) (Also known as premature ventricular contractions or PVCs, these are extra beats originating in the ventricles.)
I49.40 – Unspecified premature depolarization (Use this code when premature depolarizations are noted, but the origin – atrial, junctional, or ventricular – is not specified.)
I49.49 – Other premature depolarization (This category covers less common types of premature beats that are specified but don’t fit I49.1, I49.2, or I49.3.)
I49.5 – Sick sinus syndrome (SSS) (A condition where the sinus node, the heart’s natural pacemaker, malfunctions, leading to slow heart rates or alternating slow and fast rates.)
I49.8 – Other specified cardiac arrhythmias (This code is for specific cardiac arrhythmias not classified elsewhere, ensure to specify the arrhythmia.)
I49.9* – Cardiac arrhythmia, unspecified (Use this code when a cardiac arrhythmia is diagnosed, but the specific type is not documented.)

Chest Pain: ICD-10 Codes for Angina and Related Conditions

Chest pain is a common symptom in cardiology, and it can stem from various underlying conditions, ranging from angina to non-cardiac issues. Accurate ICD-10 coding helps differentiate cardiac chest pain from other causes.

(ICD-9-CM 411.1, 413.1, 413.9, 786.50 to 786.59 Range)
I20.0 – Unstable angina (Unstable angina is chest pain that is new, worsening, or occurs at rest, indicating a high risk of myocardial infarction.)
I20.1 – Angina pectoris with documented spasm (This refers to angina caused by coronary artery spasm, also known as Prinzmetal’s angina or variant angina.)
I20.8 – Other forms of angina pectoris (This category includes other types of angina not classified as unstable or with spasm, specify the type if known.)
I20.9 – Angina pectoris, unspecified (Use this code when angina pectoris is diagnosed, but the specific type is not documented.)
R07.1 – Chest pain on breathing (This code is for chest pain that is specifically related to respiratory movements.)
R07.2 – Precordial pain (Precordial pain refers to pain in the front of the chest, often used when the exact cause is unclear.)
R07.81 – Pleurodynia (Pain in the muscles between the ribs, often associated with viral infections.)
R07.82 – Intercostal pain (Pain originating from the intercostal nerves or muscles between the ribs.)
R07.89 – Other chest pain (This category covers other specified types of chest pain not listed above, specify the type if known.)
R07.9* – Chest pain, unspecified (Use this code when chest pain is present, but the specific nature or cause is not determined.)

Heart Failure: ICD-10 Codes Based on Type and Chronicity

Heart failure is a complex syndrome where the heart cannot pump enough blood to meet the body’s needs. ICD-10 provides detailed codes to classify heart failure based on the type (systolic, diastolic, combined) and chronicity (acute, chronic, acute on chronic).

(ICD-9-CM 428.0, 428.1, 428.20 to 428.23 Range, 428.30 TO 428.33 Range, 428.40 TO 428.43 Range, 428.9)
I50.1 – Left ventricular failure (Heart failure primarily affecting the left ventricle, the main pumping chamber of the heart.)
I50.20* – Unspecified systolic (congestive) heart failure (Systolic heart failure is characterized by reduced ejection fraction, the heart’s inability to pump blood out effectively. Use this unspecified code when details are lacking.)
I50.21 – Acute systolic (congestive) heart failure (New onset or sudden worsening of systolic heart failure.)
I50.22 – Chronic systolic (congestive) heart failure (Long-term systolic heart failure.)
I50.23 – Acute on chronic systolic (congestive) heart failure (Acute exacerbation of pre-existing chronic systolic heart failure.)
I50.30* – Unspecified diastolic (congestive) heart failure (Diastolic heart failure occurs when the heart muscle is stiff and cannot relax properly to fill with blood. Use this unspecified code when details are lacking.)
I50.31 – Acute diastolic (congestive) heart failure (New onset or sudden worsening of diastolic heart failure.)
I50.32 – Chronic diastolic (congestive) heart failure (Long-term diastolic heart failure.)
I50.33 – Acute on chronic diastolic (congestive) heart failure (Acute exacerbation of pre-existing chronic diastolic heart failure.)
I50.40* – Unspecified combined systolic (congestive) and diastolic (congestive) heart failure (Heart failure with features of both systolic and diastolic dysfunction, unspecified chronicity.)
I50.41 – Acute combined systolic (congestive) and diastolic (congestive) heart failure (New onset or sudden worsening of combined heart failure.)
I50.42 – Chronic combined systolic (congestive) and diastolic (congestive) heart failure (Long-term combined heart failure.)
I50.43 – Acute on chronic combined systolic (congestive) and diastolic (congestive) heart failure (Acute exacerbation of pre-existing chronic combined heart failure.)
I50.9* – Heart failure, unspecified (Use this code when heart failure is diagnosed, but the type and chronicity are not specified.)

Hypertension: ICD-10 Code for Primary Hypertension

Hypertension, or high blood pressure, is a major risk factor for heart disease. The most common type is essential (primary) hypertension, which has its own specific ICD-10 code.

(ICD-9-CM 401.9)
I10 – Essential (primary) hypertension (This code is for high blood pressure with no identifiable secondary cause, which constitutes the vast majority of hypertension cases.)

Nonrheumatic Valve Disorders: ICD-10 Codes for Aortic and Mitral Valve Issues

Nonrheumatic valve disorders affect the heart valves, disrupting normal blood flow. ICD-10 provides specific codes for disorders of the aortic and mitral valves, the most commonly affected valves.

Aortic Valve Disorders

(ICD-9-CM 424.1)
I35.0 – Nonrheumatic aortic (valve) stenosis (Narrowing of the aortic valve, obstructing blood flow from the left ventricle to the aorta.)
I35.1 – Nonrheumatic aortic (valve) insufficiency (Also known as aortic regurgitation, where the aortic valve doesn’t close properly, allowing blood to leak back into the left ventricle.)
I35.2 – Nonrheumatic aortic (valve) stenosis with insufficiency (A combination of both stenosis and insufficiency of the aortic valve.)
I35.8 – Other nonrheumatic aortic valve disorders (This category includes less common nonrheumatic aortic valve disorders, specify the disorder.)
I35.9* – Nonrheumatic aortic valve disorder, unspecified (Use this code when a nonrheumatic aortic valve disorder is diagnosed, but the specific type is not specified.)

Mitral Valve Disorders

(ICD-9-CM 424.0)
I34.0 – Nonrheumatic mitral (valve) insufficiency (Also known as mitral regurgitation, where the mitral valve doesn’t close properly, allowing blood to leak back into the left atrium.)
I34.1 – Nonrheumatic mitral (valve) prolapse (A condition where the mitral valve leaflets bulge back into the left atrium during systole, sometimes causing regurgitation.)
I34.2 – Nonrheumatic mitral (valve) stenosis (Narrowing of the mitral valve, obstructing blood flow from the left atrium to the left ventricle.)
I34.8 – Other nonrheumatic mitral valve disorders (This category includes less common nonrheumatic mitral valve disorders, specify the disorder.)
I34.9* – Nonrheumatic mitral valve disorder, unspecified (Use this code when a nonrheumatic mitral valve disorder is diagnosed, but the specific type is not specified.)

Atherosclerosis, Ischemia, and Infarction: Key ICD-10 Codes for Coronary Artery Disease

Coronary artery disease (CAD), encompassing atherosclerosis, ischemia, and myocardial infarction (heart attack), is a leading cause of morbidity and mortality worldwide. ICD-10 provides a detailed classification for different types and stages of CAD.

(ICD-9-CM 410.00 to 410.92 Range, 411.1, 412, 413.0, 413.1, 413.9, 414.00 to 414.07 Range, 414.10, 414.11, 414.12, 414.19, 414.2, 414.3, 414.4, 414.8, 414.9, 429.2, 429.5, 429.6, 429.71, 429.79)
I21.01 – ST elevation (STEMI) myocardial infarction involving left main coronary artery (STEMI heart attack due to blockage of the left main coronary artery.)
I21.02 – ST elevation (STEMI) myocardial infarction involving left anterior descending coronary artery (STEMI heart attack due to blockage of the left anterior descending artery, often called the “widow maker”.)
I21.09 – ST elevation (STEMI) myocardial infarction involving other coronary artery of anterior wall (STEMI heart attack in other anterior wall arteries.)
I21.11 – ST elevation (STEMI) myocardial infarction involving right coronary artery (STEMI heart attack due to blockage of the right coronary artery.)
I21.19 – ST elevation (STEMI) myocardial infarction involving other coronary artery of inferior wall (STEMI heart attack in other inferior wall arteries.)
I21.21 – ST elevation (STEMI) myocardial infarction involving left circumflex coronary artery (STEMI heart attack due to blockage of the left circumflex artery.)
I21.29 – ST elevation (STEMI) myocardial infarction involving other sites (STEMI heart attack in locations not specifically listed above.)
I21.3 – ST elevation (STEMI) myocardial infarction of unspecified site (STEMI heart attack, but the affected coronary artery is not specified.)
I21.4 – Non-ST elevation (NSTEMI) myocardial infarction (NSTEMI heart attack, another type of acute myocardial infarction.)
I22.0 – Subsequent ST elevation (STEMI) myocardial infarction of anterior wall (A new STEMI heart attack in the anterior wall, occurring after a previous myocardial infarction.)
I22.1 – Subsequent ST elevation (STEMI) myocardial infarction of inferior wall (A new STEMI heart attack in the inferior wall, after a previous MI.)
I22.2 – Subsequent non-ST elevation (NSTEMI) myocardial infarction (A new NSTEMI heart attack after a previous MI.)
I22.8 – Subsequent ST elevation (STEMI) myocardial infarction of other sites (A new STEMI heart attack in other sites, after a previous MI.)
I22.9 – Subsequent ST elevation (STEMI) myocardial infarction of unspecified site (A new STEMI heart attack of unspecified site, after a previous MI.)
I23.0 – Hemopericardium as current complication following acute myocardial infarction (Bleeding into the pericardial sac around the heart as a complication of a recent heart attack.)
I23.1 – Atrial septal defect as current complication following acute myocardial infarction (Development of an atrial septal defect as a complication of a recent heart attack.)
I23.2 – Ventricular septal defect as current complication following acute myocardial infarction (Development of a ventricular septal defect as a complication of a recent heart attack.)
I23.3 – Rupture of cardiac wall without hemopericardium as current complication following acute myocardial infarction (Rupture of the heart wall (not involving the pericardium) as a complication of a recent heart attack.)
I23.4 – Rupture of chordae tendineae as current complication following acute myocardial infarction (Rupture of the chordae tendineae, supporting structures of the heart valves, as a complication of a recent heart attack.)
I23.5 – Rupture of papillary muscle as current complication following acute myocardial infarction (Rupture of the papillary muscles, also involved in valve function, as a complication of a recent heart attack.)
I23.6 – Thrombosis of atrium, auricular appendage, and ventricle as current complications following acute myocardial infarction (Blood clots forming in the heart chambers as a complication of a recent heart attack.)
I23.7 – Postinfarction angina (Angina occurring after a myocardial infarction.)
I23.8 – Other current complications following acute myocardial infarction (Other specified complications occurring after a recent heart attack.)
I25.10 – Atherosclerotic heart disease of native coronary artery without angina pectoris (CAD without chest pain.)
I25.110 – Atherosclerotic heart disease of native coronary artery with unstable angina pectoris (CAD with unstable angina.)
I25.111 – Atherosclerotic heart disease of native coronary artery with angina pectoris with documented spasm (CAD with angina due to coronary artery spasm.)
I25.118 – Atherosclerotic heart disease of native coronary artery with other forms of angina pectoris (CAD with other specified types of angina.)
I25.119* – Atherosclerotic heart disease of native coronary artery with unspecified angina pectoris (CAD with angina, type unspecified.)
I25.2 – Old myocardial infarction (History of a past heart attack.)
I25.3 – Aneurysm of heart (Weakening and bulging of a part of the heart wall.)
I25.41 – Coronary artery aneurysm (Aneurysm of a coronary artery.)
I25.42 – Coronary artery dissection (Tear in the wall of a coronary artery.)
I25.5 – Ischemic cardiomyopathy (Heart muscle damage due to chronic ischemia from CAD.)
I25.6 – Silent myocardial ischemia (Myocardial ischemia without typical chest pain symptoms.)
I25.700* – Atherosclerosis of coronary artery bypass graft(s), unspecified, with unstable angina pectoris (Atherosclerosis in bypass grafts, unspecified type, with unstable angina.)
I25.701* – Atherosclerosis of coronary artery bypass graft(s), unspecified, with angina pectoris with documented spasm (Atherosclerosis in bypass grafts, unspecified type, with angina due to spasm.)
I25.708* – Atherosclerosis of coronary artery bypass graft(s), unspecified, with other forms of angina pectoris (Atherosclerosis in bypass grafts, unspecified type, with other angina types.)
I25.709* – Atherosclerosis of coronary artery bypass graft(s), unspecified, with unspecified angina pectoris (Atherosclerosis in bypass grafts, unspecified type, with angina, type unspecified.)
I25.710 – Atherosclerosis of autologous vein coronary artery bypass graft(s) with unstable angina pectoris (Atherosclerosis in vein bypass grafts with unstable angina.)
I25.711 – Atherosclerosis of autologous vein coronary artery bypass graft(s) with angina pectoris with documented spasm (Atherosclerosis in vein bypass grafts with angina due to spasm.)
I25.718 – Atherosclerosis of autologous vein coronary artery bypass graft(s) with other forms of angina pectoris (Atherosclerosis in vein bypass grafts with other angina types.)
I25.719* – Atherosclerosis of autologous vein coronary artery bypass graft(s) with unspecified angina pectoris (Atherosclerosis in vein bypass grafts with angina, type unspecified.)
I25.720 – Atherosclerosis of autologous artery coronary artery bypass graft(s) with unstable angina pectoris (Atherosclerosis in artery bypass grafts with unstable angina.)
I25.721 – Atherosclerosis of autologous artery coronary artery bypass graft(s) with angina pectoris with documented spasm (Atherosclerosis in artery bypass grafts with angina due to spasm.)
I25.728 – Atherosclerosis of autologous artery coronary artery bypass graft(s) with other forms of angina pectoris (Atherosclerosis in artery bypass grafts with other angina types.)
I25.729* – Atherosclerosis of autologous artery coronary artery bypass graft(s) with unspecified angina pectoris (Atherosclerosis in artery bypass grafts with angina, type unspecified.)
I25.730 – Atherosclerosis of nonautologous biological coronary artery bypass graft(s) with unstable angina pectoris (Atherosclerosis in non-biological bypass grafts with unstable angina.)
I25.731 – Atherosclerosis of nonautologous biological coronary artery bypass graft(s) with angina pectoris with documented spasm (Atherosclerosis in non-biological bypass grafts with angina due to spasm.)
I25.738 – Atherosclerosis of nonautologous biological coronary artery bypass graft(s) with other forms of angina pectoris (Atherosclerosis in non-biological bypass grafts with other angina types.)
I25.739* – Atherosclerosis of nonautologous biological coronary artery bypass graft(s) with unspecified angina pectoris (Atherosclerosis in non-biological bypass grafts with angina, type unspecified.)
I25.750 – Atherosclerosis of native coronary artery of transplanted heart with unstable angina (Atherosclerosis in the original arteries of a transplanted heart with unstable angina.)
I25.751 – Atherosclerosis of native coronary artery of transplanted heart with angina pectoris with documented spasm (Atherosclerosis in original arteries of a transplanted heart with angina due to spasm.)
I25.758 – Atherosclerosis of native coronary artery of transplanted heart with other forms of angina pectoris (Atherosclerosis in original arteries of a transplanted heart with other angina types.)
I25.759* – Atherosclerosis of native coronary artery of transplanted heart with unspecified angina pectoris (Atherosclerosis in original arteries of a transplanted heart with angina, type unspecified.)
I25.760 – Atherosclerosis of bypass graft of coronary artery of transplanted heart with unstable angina (Atherosclerosis in bypass grafts of a transplanted heart with unstable angina.)
I25.761 – Atherosclerosis of bypass graft of coronary artery of transplanted heart with angina pectoris with documented spasm (Atherosclerosis in bypass grafts of a transplanted heart with angina due to spasm.)
I25.768 – Atherosclerosis of bypass graft of coronary artery of transplanted heart with other forms of angina pectoris (Atherosclerosis in bypass grafts of a transplanted heart with other angina types.)
I25.769* – Atherosclerosis of bypass graft of coronary artery of transplanted heart with unspecified angina pectoris (Atherosclerosis in bypass grafts of a transplanted heart with angina, type unspecified.)
I25.790 – Atherosclerosis of other coronary artery bypass graft(s) with unstable angina pectoris (Atherosclerosis in other types of bypass grafts with unstable angina.)
I25.791 – Atherosclerosis of other coronary artery bypass graft(s) with angina pectoris with documented spasm (Atherosclerosis in other bypass graft types with angina due to spasm.)
I25.798 – Atherosclerosis of other coronary artery bypass graft(s) with other forms of angina pectoris (Atherosclerosis in other bypass graft types with other angina types.)
I25.799* – Atherosclerosis of other coronary artery bypass graft(s) with unspecified angina pectoris (Atherosclerosis in other bypass graft types with angina, type unspecified.)
I25.810 – Atherosclerosis of coronary artery bypass graft(s) without angina pectoris (Atherosclerosis in bypass grafts without angina.)
I25.811 – Atherosclerosis of native coronary artery of transplanted heart without angina pectoris (Atherosclerosis in original arteries of a transplanted heart without angina.)
I25.812 – Atherosclerosis of bypass graft of coronary artery of transplanted heart without angina pectoris (Atherosclerosis in bypass grafts of a transplanted heart without angina.)
I25.82 – Chronic total occlusion of coronary artery (Complete blockage of a coronary artery lasting for a prolonged period.)
I25.83 – Coronary atherosclerosis due to lipid rich plaque (CAD specifically caused by lipid-rich plaque buildup.)
I25.84 – Coronary atherosclerosis due to calcified coronary lesion (CAD specifically caused by calcified plaque.)
I25.89 – Other forms of chronic ischemic heart disease (Other specified forms of long-term heart ischemia due to CAD.)
I25.9* – Chronic ischemic heart disease, unspecified (Long-term heart ischemia due to CAD, unspecified type.)

Syncope and Collapse: ICD-10 Code for Loss of Consciousness

Syncope, or fainting, and collapse can sometimes be related to cardiac issues, particularly arrhythmias. While not always cardiac in origin, it’s important to consider cardiac causes and utilize the appropriate ICD-10 code when relevant.

(ICD-9-CM 780.2)
R55 – Syncope and collapse (This code is used for transient loss of consciousness due to reduced blood flow to the brain. It is a symptom code and further investigation is needed to determine the underlying cause, which could be cardiac or non-cardiac.)

Disclaimer: This guide provides a general overview of common cardiac diagnosis codes in ICD-10. It is intended for informational purposes only and should not be considered a substitute for professional medical coding advice or comprehensive ICD-10 training materials. Always consult official ICD-10 coding guidelines and resources for accurate and up-to-date coding practices.