Cardiac Arrhythmia ICD-10-CM Coding

Cardiac Arrhythmia Image

One of the more common cardiac conditions or diagnosis is arrhythmia, referring to an abnormal heartbeat. Cardiac arrhythmias can occur over several years or even be life-long in duration. There are several different types of arrhythmias and they vary in severity. The ICD-10-CM classification captures many different types and severity of arrhythmias. Ensuring ones understanding both clinically and for the classification system can aide in medical coding accuracy.

Cardiac arrhythmia is a fairly common diagnosis (condition) and is reported to be identified in approximately 3 million cases annually in the United States. Arrhythmia is caused by changes in heart tissue and activity or in the electrical signals that controls the heartbeat. These changes can be caused by damage from disease, injury, or genetics. Often there are no symptoms, but some people can feel an irregular heartbeat.

Some of the most common causes of an irregular heartbeats are:

  • Alcohol abuse
  • Drug Abuse
  • Smoking
  • Excessive caffeine consumption
  • Mental stress
  • Certain medications
  • Certain Dietary Supplements
  • Obesity
  • Diabetes
  • High Blood Pressure
  • Chronic Kidney Disease

Heart rate is measured by the number of beats per minute or bpm. While resting the heart rate will be lower than when one exercises. The normal resting heart rate for adults ranges from 60 and 100 beats per minute.  A faster than normal heart rate is called “tachycardia” and a slower than normal heart rate  is called “bradycardia”. In addition to tachycardia and bradycardia, there are other types of arrhythmias which include:

  • Atrial fibrillation: Abnormal electrical impulses in the atria.
  • Atrial flutter: Similar to atrial fibrillation, but the heartbeats are more organized
  • Conduction block: Arrhythmia results when heart’s electrical pathways are blocked.
  • Long QT syndrome: Fast and chaotic heartbeats that can be life-threatening.
  • Premature contraction: An early heartbeat.
  • Supraventricular tachycardia: Includes all arrythmias that start above the ventricles.
  • Sick sinus syndrome: Slowed, disrupted, or blocked electrical impulses from the sinus node.
  • Ventricular tachycardia: tachycardia: Abnormal electrical pulses in the ventricles causing rapid, but regular heart beats.
  • Ventricular Fibrillation: Abnormal electrical pulses in the ventricles lead to reduce blood supply to the body.
  • Wolff-Parkinson-White syndrome: An additional electrical pathway is present between the atria and ventricles at birth.


Individuals with heart disease and/or heart failure can also experience irregular cardiac arrhythmias so it is a best practice to review the clinical documentation and cardiac testing results carefully. These cardiac conditions are often accompanied by a flutter in the heart or chest, chest pain and even shortness of breath in addition to the arrhythmia. In order to properly diagnose the specific type of arrythmia, the healthcare provider will conduct a physical examination and order an electrocardiogram and/or Holter monitor.

With atrial fibrillation, the atria does not contract normally.  Instead, it will ‘quiver’ and blood will not be pushed down into the ventricles as it should be. In atrial fibrillation, the beat is irregular. The biggest risk factor with atrial fibrillation is that the blood, while trapped in the atria will coagulate, or form a clot. This clot then can be pushed through the heart and even become lodged in an artery or travel to the brain causing a stroke.

Within ICD-10-CM you will find that Chapter 9 Circulatory System (I00-I99) contains that codes for cardiac arrythmias in the specific code range for “Other forms of heart disease”, I30-I5A. 

The following lists the ICD-10-CM classification for Atrial fibrillation and flutter, some of the codes have five characters for specificity:

I48 Atrial fibrillation and flutter

I48.0 Paroxysmal atrial fibrillation

I48.1 Persistent atrial fibrillation

Excludes1: Permanent atrial fibrillation (I48.21)

I48.11 Longstanding persistent atrial fibrillation

I48.19 Other persistent atrial fibrillation

Chronic persistent atrial fibrillation

Persistent atrial fibrillation, NOS

I48.2 Chronic atrial fibrillation

I48.20 Chronic atrial fibrillation, unspecified

Excludes1: Chronic persistent atrial fibrillation (I48.19)

I48.21 Permanent atrial fibrillation

I48.3 Typical atrial flutter

Type I atrial flutter

I48.4 Atypical atrial flutter

Type II atrial flutter

I48.9 Unspecified atrial fibrillation and atrial flutter

I48.91 Unspecified atrial fibrillation

I48.92 Unspecified atrial flutter

As you can see from the above, there are many specific codes, so we are needing to have specific documentation in the health record. There will be times when the medical coding and/or CDI professional will need to query the healthcare provider, always following the AHIMA/ACDIS 2022 Query Practice Brief for your query wording and for when and when not to query.

Always be sure to conduct a complete and thorough review of the health record in order to obtain accurate clinical coding.

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