2022 ICD-10-CM Code I46.9
Cardiac arrest, cause unspecified

Version 2022
ICD-10:I46.9
Short Description:Cardiac arrest, cause unspecified
Long Description:Cardiac arrest, cause unspecified
Status: Valid for Submission

Code Classification

  • Diseases of the circulatory system (I00–I99)
    • Other forms of heart disease (I30-I5A)
      • Cardiac arrest (I46)

I46.9 is a billable diagnosis code used to specify a medical diagnosis of cardiac arrest, cause unspecified. The code I46.9 is valid during the fiscal year 2022 from October 01, 2021 through September 30, 2022 for the submission of HIPAA-covered transactions.

The ICD-10-CM code I46.9 might also be used to specify conditions or terms like asystole, atrial standstill, cardiac arrest, cardiac arrest after obstetrical surgery and/or other procedure including delivery, cardiac arrest and/or failure following anesthesia and/or sedation in labor and/or delivery , cardiac arrest with successful resuscitation, etc.

Unspecified diagnosis codes like I46.9 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.

Entries in the Index to Diseases and Injuries with references to I46.9

The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10 code(s). The following references for the code I46.9 are found in the index:

Approximate Synonyms

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

Convert I46.9 to ICD-9 Code

The General Equivalency Mapping (GEM) crosswalk indicates an approximate mapping between the ICD-10 code I46.9 its ICD-9 equivalent. The approximate mapping means there is not an exact match between the ICD-10 code and the ICD-9 code and the mapped code is not a precise representation of the original code.

Information for Patients


Sudden Cardiac Arrest

What is sudden cardiac arrest (SCA)?

Sudden cardiac arrest (SCA) is a condition in which the heart suddenly stops beating. When that happens, blood stops flowing to the brain and other vital organs. If it is not treated, SCA usually causes death within minutes. But quick treatment with a defibrillator may be lifesaving.

How is sudden cardiac arrest (SCA) different from a heart attack?

A heart attack is different from an SCA. A heart attack happens when blood flow to the heart is blocked. During a heart attack, the heart usually doesn't suddenly stop beating. With an SCA, the heart stops beating.

Sometimes an SCA can happen after or during recovery from a heart attack.

What causes sudden cardiac arrest (SCA)?

Your heart has an electrical system that controls the rate and rhythm of your heartbeat. An SCA can happen when the heart's electrical system is not working right and causes irregular heartbeats. Irregular heartbeats are called arrhythmias. There are different types. They may cause the heart to beat too fast, too slow, or with an irregular rhythm. Some can cause the heart to stop pumping blood to the body; this is the type that causes SCA.

Certain diseases and conditions can cause the electrical problems that lead to SCA. They include

Who is at risk for sudden cardiac arrest (SCA)?

You are at higher risk for SCA if you

What are the symptoms of sudden cardiac arrest (SCA)?

Usually, the first sign of SCA is loss of consciousness (fainting). This happens when the heart stops beating.

Some people may have a racing heartbeat or feel dizzy or light-headed just before they faint. And sometimes people have chest pain, shortness of breath, nausea, or vomiting in the hour before they have an SCA.

How is sudden cardiac arrest (SCA) diagnosed?

SCA happens without warning and requires emergency treatment. Health care providers rarely diagnose SCA with medical tests as it's happening. Instead, it is usually diagnosed after it happens. Providers do this by ruling out other causes of a person's sudden collapse.

If you are at high risk for SCA, your provider may refer you to a cardiologist, a doctor who specializes in heart diseases. The cardiologist may ask you to get various heart health tests to see how well you heart is working. He or she will work with you to decide whether you need treatment to prevent SCA.

What are the treatments for sudden cardiac arrest (SCA)?

SCA is an emergency. A person having SCA needs to be treated with a defibrillator right away. A defibrillator is a device sends an electric shock to the heart. The electric shock can restore a normal rhythm to a heart that's stopped beating. To work well, it needs to be done within minutes of the SCA.

Most police officers, emergency medical technicians, and other first responders are trained and equipped to use a defibrillator. Call 9-1-1 right away if someone has signs or symptoms of SCA. The sooner you call for help, the sooner lifesaving treatment can begin.

What should I do if I think that someone has had an SCA?

Many public places such as schools, businesses, and airports have automated external defibrillators (AEDs). AEDs are special defibrillators that untrained people can use if they think that someone has had SCA. AEDS are programmed to give an electric shock if they detect a dangerous arrhythmia. This prevents giving a shock to someone who may have fainted but isn't having SCA.

If you see someone who you think has had SCA, you should give cardiopulmonary resuscitation (CPR) until defibrillation can be done.

People who are at risk for SCA may want to consider having an AED at home. Ask your cardiologist to help you decide whether having an AED in your home might help you.

What are the treatments after surviving sudden cardiac arrest (SCA)?

If you survive SCA, you'll likely be admitted to a hospital for ongoing care and treatment. In the hospital, your medical team will closely watch your heart. They may give you medicines to try to reduce the risk of another SCA.

They will also try to find out what caused your SCA. If you're diagnosed with coronary artery disease, you may have an angioplasty or coronary artery bypass surgery. These procedures help restore blood flow through narrowed or blocked coronary arteries.

Often, people who have had SCA get a device called an implantable cardioverter defibrillator (ICD). This small device is surgically placed under the skin in your chest or abdomen. An ICD uses electric pulses or shocks to help control dangerous arrhythmias.

Can sudden cardiac arrest (SCA) be prevented?

You may be able to lower your risk of SCA by following a heart-healthy lifestyle. If you have coronary artery disease or another heart disease, treating that disease can also lower your risk of SCA. If you have had an SCA, getting an implantable cardioverter defibrillator (ICD) can lower your chance of having another SCA.

NIH: National Heart, Lung, and Blood Institute


[Learn More in MedlinePlus]

Code History

  • 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 (First year ICD-10-CM implemented into the HIPAA code set)