2024 ICD-10-CM Diagnosis Code I48.91

Unspecified atrial fibrillation

ICD-10-CM Code:
I48.91
ICD-10 Code for:
Unspecified atrial fibrillation
Is Billable?
Yes - Valid for Submission
Chronic Condition Indicator: [1]
Chronic
Code Navigator:

Code Classification

  • Diseases of the circulatory system
    (I00–I99)
    • Other forms of heart disease
      (I30-I5A)
      • Atrial fibrillation and flutter
        (I48)

I48.91 is a billable diagnosis code used to specify a medical diagnosis of unspecified atrial fibrillation. The code is valid during the current fiscal year for the submission of HIPAA-covered transactions from October 01, 2023 through September 30, 2024.

The code is commonly used in family practice, internal medicine , cardiology medical specialties to specify clinical concepts such as other forms of heart disease.

Unspecified diagnosis codes like I48.91 are acceptable when clinical information is unknown or not available about a particular condition. Although a more specific code is preferable, unspecified codes should be used when such codes most accurately reflect what is known about a patient's condition. Specific diagnosis codes should not be used if not supported by the patient's medical record.

Approximate Synonyms

The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:

  • Accelerated atrioventricular conduction
  • Atrial fibrillation
  • Atrial fibrillation and flutter
  • Atrial fibrillation with rapid ventricular response
  • Atrial flutter
  • Controlled atrial fibrillation
  • Familial atrial fibrillation
  • Hypercoagulability state
  • Hypercoagulable state due to atrial fibrillation
  • Lone atrial fibrillation
  • Preexcited atrial fibrillation
  • Rapid atrial fibrillation
  • Transient cerebral ischemia due to atrial fibrillation

Clinical Classification

Clinical Information

  • Atrial Fibrillation

    abnormal cardiac rhythm that is characterized by rapid, uncoordinated firing of electrical impulses in the upper chambers of the heart (heart atria). in such case, blood cannot be effectively pumped into the lower chambers of the heart (heart ventricles). it is caused by abnormal impulse generation.
  • Atrial Flutter

    rapid, irregular atrial contractions caused by a block of electrical impulse conduction in the right atrium and a reentrant wave front traveling up the inter-atrial septum and down the right atrial free wall or vice versa. unlike atrial fibrillation which is caused by abnormal impulse generation, typical atrial flutter is caused by abnormal impulse conduction. as in atrial fibrillation, patients with atrial flutter cannot effectively pump blood into the lower chambers of the heart (heart ventricles).

Index to Diseases and Injuries References

The following annotation back-references for this diagnosis code are found in the injuries and diseases index. The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10-CM code(s).

Convert I48.91 to ICD-9-CM

  • ICD-9-CM Code: 427.31 - Atrial fibrillation
    Approximate Flag - The approximate mapping means there is not an exact match between the ICD-10 and ICD-9 codes and the mapped code is not a precise representation of the original code.

Patient Education


Atrial Fibrillation

What is atrial fibrillation (AFib)?

Atrial fibrillation, also known as AFib or AF, is one of the most common types of arrhythmias. Arrhythmias are problems with the rate or rhythm of your heartbeat. They can cause your heart to beat too slowly, too fast, or in an irregular way.

If you have AFib, your heart beats irregularly and sometimes much faster than normal. Also, your heart's upper and lower chambers do not work together as they should. When this happens, the lower chambers do not fill completely or pump enough blood to your lungs and body. This can cause symptoms such as dizziness, fatigue, and a pounding heartbeat.

AFib may happen in brief episodes, or it may be a permanent condition. It's very important to treat it, since AFib can put you at risk for stroke and other heart conditions.

What causes atrial fibrillation (AFib)?

AFib is most often caused by changes to the heart's tissue or the electrical signaling that helps the heartbeat. These changes can happen due to different conditions and factors, such as high blood pressure, coronary artery disease, congenital heart defects, infections, and aging. Sometimes the cause is unknown.

Who is more likely to develop atrial fibrillation (AFib)?

Anyone can develop AFib, but there are certain things that raise your risk for it:

  • Aging. The risk of atrial fibrillation increases as you get older, especially when you are over age 65.
  • Family history and genetics. AFib can run in families. So can heart disease, which raises your risk of AFib.
  • Some lifestyle choices. Your risk is higher if you drink a lot of alcohol, use certain illegal drugs such as cocaine and methamphetamines, or smoke.
  • Having certain health conditions, such as:
    • High blood pressure
    • Diabetes
    • Heart failure
    • Heart valve diseases
    • Obesity
    • Hyperthyroidism
    • Chronic kidney disease
    • COPD and other lung diseases
    • Sleep apnea
  • Race. AFib is more common in people with European ancestry.
  • Recent surgery. You may be at risk of atrial fibrillation in the early days and weeks after surgery on your heart, lungs, or esophagus.

What are the symptoms of atrial fibrillation (AFib)?

Some people who have AFib don't have any symptoms and don't know they have it. If you do have symptoms, you may only notice them once in a while. Or you may have symptoms that are more frequent. And in some cases, the symptoms might be severe. If you have heart disease, you are more likely to notice your symptoms. And those symptoms could get worse if your heart disease gets worse.

The symptoms of AFib can include:

  • Extreme fatigue, which is the most common symptom
  • Heart palpitations (the feeling that your heart is skipping a beat, fluttering, pounding, or beating too hard or too fast)
  • Trouble breathing, especially when lying down or when exercising
  • Chest pain
  • Dizziness or fainting
  • Low blood pressure

What other problems can AFib cause?

If AFib is not treated, it can lead to serious health problems (complications) such as:

  • Stroke
  • Heart failure
  • Blood clots
  • Sudden cardiac arrest (SCA)
  • Cognitive impairment and dementia

To help prevent these problems, it's important to contact your health care provider if you are having symptoms. If you do have AFib, the sooner you are diagnosed and treated, the better.

How is atrial fibrillation (AFib) diagnosed?

To find out if you have AFib, your provider:

  • Will ask about your medical history, including your symptoms, lifestyle, and any other health conditions you may have
  • Will ask about your family history, to find out if you have relatives who have or had AFib
  • Will do a physical exam
  • May order blood tests
  • Will likely order heart tests, such as an electrocardiogram (also called an EKG or ECG) and echocardiogram
  • May ask you to wear a heart monitor device that records your heart's electrical activity

What are the treatments for atrial fibrillation (AFib)?

The treatments for AFib may include:

  • Blood thinner medicines that help prevent blood clots from forming.
  • Medicines to control your heart's rhythm and rate.
  • Following heart-healthy lifestyle changes, such as:
    • Following a heart-healthy eating plan that limits saturated fats, salt, and cholesterol. An example is the DASH eating plan.
    • Limiting or avoiding alcohol, because it can increase your heart rate.
    • Aiming for a healthy weight.
    • Getting regular physical activity.
    • Managing stress.
    • Quitting smoking.
  • Procedures such as:
    • Electrical cardioversion, which restores your heart rhythm using low-energy shocks to your heart.
    • Catheter ablation, which scars the tissue that is causing the arrhythmia. The scar tissue blocks the abnormal heart signals.
  • Surgeries such as:
    • Surgery to put in a pacemaker to help control the arrhythmia.
    • A Maze procedure, which creates scar tissue in a maze-like pattern in certain parts of the heart.
    • Left atrial appendage closure, a surgery on a small sac in the muscle wall of your left atrium (the upper left chamber of your heart). It helps prevent blood clots and can reduce your risk of stroke. This surgery is for people who are not able to take blood thinners.

Can atrial fibrillation (AFib) be prevented?

There are steps you can take to help lower your risk of atrial fibrillation, such as:

  • Making heart-healthy lifestyle changes:
    • Following a heart-healthy eating plan
    • Limiting or avoiding alcohol
    • Aiming for a healthy weight
    • Getting regular physical activity
    • Managing stress
    • Not smoking
  • Avoiding illegal drugs, such as cocaine and methamphetamines
  • Taking antiarrhythmic medicine (medicine to treat arrhythmia) if you are having heart surgery
  • Treating any health conditions that could raise your risk of AFib

NIH: National Heart, Lung, and Blood Institute


[Learn More in MedlinePlus]

Code History

  • FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
  • FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
  • FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.