ICD-10 Primer for Cardiology

cardiology icd 10 codes: afib, chf, and moreContinuing our series on ICD-10 basics we are offering high-level primers to illustrate the differences on specific documentation requirements for various specialties. We will also give some samples of how ICD-9-CM codes common for those specialties compare to ICD-10-CM codes. Again, much of the material in these speciality-specific blog posts is based on guidelines and material published by CMS in their Road to 10 Series. There is a lot of questionable information and advice out there and we want to help improve the consistency and reduce the uncertainty by going to the source of regulations. We will summarize and consolidate to enhance readability and brevity. The application of ICD-10 documentation requirements and the common ICD-10 Cardiology codes is the focus of this post. In ICD-10-CM, there are three main categories of changes:

  1. Definition Changes
  2. Terminology differences
  3. Increased specificity

For Cardiology, the focus of ICD-10 is generally on the focus is increased specificity and documenting the downstream effects of the patient’s condition. AMI Definition Change When documenting an AMI in ICD-10, keep the following in mind:

  • Timeframe An AMI will now be considered “acute” for 4 weeks from the time of the incident, a revised timeframe from the current ICD-9 period of 8 weeks.
  • Episode of care ICD-10 does not capture episode of care (e.g. initial, subsequent, sequelae).
  • Subsequent AMI ICD-10 allows coding of a new MI that occurs during the 4 week “acute period” of the original AMI.

ICD-10 Code Examples for AMI

I21.02 ST elevation (STEMI) myocardial infarction involving left anterior descending coronary artery
I21.4 Non-ST elevation (NSTEMI) myocardial infarction
I22.1 Subsequent ST elevation (STEMI) myocardial infarction of inferior wall

HYPERTENSION Definition Change In ICD-10, hypertension is defined as essential (primary). The concept of “benign or malignant” as it relates to hypertension no longer exists. When documenting hypertension, include the following:

  • Type E.g. Essential, secondary, etc.
  • Causal relationship E.g. Renal, pulmonary, etc.

ICD-10 Code Examples for Hypertension

I10 Essential (primary) hypertension
I11.9 Hypertensive heart disease without heart failure
I15.0 Renovascular hypertension

CONGESTIVE HEART FAILURE Terminology Differences & Increased Specificity The terminology used in ICD-10 exactly matches the types of CHF. If you document “decompensation” or “exacerbation,” the CHF type will be coded as “acute on chronic.” When documenting CHF, include the following:

  • Acuity e.g. Acute, chronic
  • Type e.g. Systolic, diastolic

Examples of ICD-10 Codes for CHF Exacerbation or Decompensation

I50.23 Acute on chronic systolic (congestive) heart failure
I50.33 Acute on chronic diastolic (congestive) heart failure
I50.43 Acute on chronic combined systolic (congestive) and diastolic (congestive) heart failure

UNDERDOSING Terminology Difference Underdosing is an important new concept and term in ICD-10. It allows you to identify when a patient is taking less of a medication than is prescribed. When documenting underdosing, include the following:

  • Intentional, Unintentional, Non-compliance Is the underdosing deliberate? (e.g., patient refusal)
  • Reason Why is the patient not taking the medication? (e.g. financial hardship, age-related debility)

ICD-10 Code Examples for Underdosing

Z91.120 Patient’s intentional underdosing of medication regimen due to financial hardship
T36.4x6A Underdosing of tetracyclines, initial encounter
T45.526D Underdosing of antithrombotic drugs, subsequent encounter

ATHEROCLEROTIC HEART DISEASE WITH ANGINA PECTORIS Terminology Difference When documenting atherosclerotic heart disease with angina pectoris, include the following:

  • Cause Assumed to be atherosclerosis; notate if there is another cause
  • Stability e.g. Stable angina pectoris, unstable angina pectoris
  • Vessel Note which artery (if known) is involved and whether the artery is native or autologous
  • Graft involvement -  If appropriate, whether a bypass graft was involved in the angina pectoris diagnosis; also note the original location of the graft and whether it is autologous or biologic

ICD-10 Code Examples for Atheroclerotic Heart Disease with Angina Petoris

I25.110 Atherosclerotic heart disease of a native coronary artery with unstable angina pectoris
I25.710 Atherosclerosis of autologous vein coronary artery bypass graft(s) with unstable angina pectoris

ARRYTHMIAS/DYSRHYTHMIA Increased Specificity When documenting arrhythmias, include the following:

  • Location e.g. Atrial, ventricular, supraventricular, etc.
  • Rhythm name e.g. Flutter, fibrillation, type 1 atrial flutter, long QT syndrome, sick sinus syndrome, etc.
  • Acuity e.g. Acute, chronic, etc.
  • Cause e.g., Hyperkalemia, hypertension, alcohol consumption, digoxin, amiodarone, verapamil HCl

ICD-10 Code Examples for Arrythmias/Dysrhythmia

I48.2 Chronic atrial fibrillation (afib)
I49.01 Ventricular fibrillation

Comparison of ICD-9-CM Codes to ICD-10-CM Codes for Atrial Fibrillation and Flutter: ICD-9-CM Codes

427.31 Atrial Fibrillation
427.32 Atrial Flutter

ICD-10-CM Codes

I48.0 Paroxysmal atrial fibrillation
I48.1 Persistent atrial fibrillation
I48.2 Chronic atrial fibrillation
I48.3 Typical atrial flutter
I48.4 Atypical atrial flutter
I48.91* Unspecified atrial fibrillation
I48.92* Unspecified atrial flutter

*Codes with a greater degree of specificity should be considered first. For a comprehensive list of ICD-10 diagnosis codes you can download the following files by clicking on the appropriate links:

Join Our Newsletter

Get Updates Direct to Your Inbox. Gain access to a rich library of articles, white papers, webinars, podcasts and more. Register today to receive eMDs Insights newsletter.

Specialty *
State *