The ICD medical abbreviation has two main meanings: in cardiology it names an implantable cardioverter defibrillator, a battery device implanted in the chest that tracks the heartbeat and can deliver a shock to reset a dangerous rhythm, and in medical records and billing it is the International Classification of Diseases, the code system used for diagnoses.
Which one a document means is usually obvious from the setting. A heart note, a device check or a discharge summary for heart failure points to the device. A claim, a coding course or a problem list with letters and numbers such as I10 points to the code set. This page covers both, plus two less common clinical meanings.
At a glance
Stands for (cardiology)
Implantable cardioverter defibrillatorStands for (coding)
International Classification of Diseases, kept by the World Health OrganizationOther meanings
Intercostal drain (a chest tube, UK and Australia); irritant contact dermatitisRelated device terms
US code version
ICD-10-CM for diagnoses, ICD-10-PCS for inpatient proceduresWhere you see it
Cardiology notes, device clinics, claims, problem lists
ICD medical abbreviation cardiology meaning
The generator is a sealed metal case a little smaller than a deck of cards, usually set beneath the skin under the left collarbone. Insulated leads travel from it along a vein and end inside the heart chambers. The device listens to every heartbeat. If it detects a dangerously fast rhythm from the lower chambers, such as ventricular tachycardia or ventricular fibrillation, it can pace the heart quickly to break the rhythm or deliver a shock.
ICDs are placed for people who have survived sudden cardiac arrest, and to prevent it in people at high risk, for example those with a weak heart pump from heart failure or certain inherited heart conditions. Most ICDs also work as pacemakers when the heart beats too slowly.
Device shorthand around an ICD
Device notes use many related terms. This table sorts the common ones.
| Term | Meaning | Can it shock? |
|---|---|---|
| ICD | Implantable cardioverter defibrillator | Yes |
| AICD | Automatic implantable cardioverter defibrillator, an older name for the same device | Yes |
| S-ICD | Subcutaneous ICD with a lead under the skin, not inside the heart | Yes |
| CRT-D | Cardiac resynchronization therapy with a defibrillator | Yes |
| PPM | Permanent pacemaker | No, it only paces |
Device clinic note: "Dual chamber ICD interrogated. Battery 6 yrs. 1 episode VT terminated by ATP, no shocks." The device was checked, the battery has years left, and it stopped one fast rhythm with rapid pacing instead of a shock.
Living with an implanted defibrillator
People with an ICD usually have regular device checks in clinic and remote monitoring from home through a bedside or phone based transmitter. Teams often give advice about keeping strong magnets and some electrical equipment away from the device, and about telling security staff and other clinicians about it. An MRI may be possible only with certain systems and special settings.
A shock feels like a sudden hard thump in the chest. Clinics give each patient written steps about when to call after a shock and when to call emergency services, such as several shocks in a row or a shock with chest pain or fainting. Driving rules after a shock or implant also vary and are explained by the care team.
ICD codes in records and billing
In health information work, ICD means the International Classification of Diseases, a worldwide system that gives every diagnosis, symptom and injury a code. The World Health Organization maintains it. In the United States, the clinical version ICD-10-CM is used for diagnosis codes on claims and records, and ICD-10-PCS is used for procedures done during inpatient stays. A newer edition, ICD-11, has been adopted by the World Health Organization and is in use in some countries.
| Code | Diagnosis |
|---|---|
| I10 | Essential (primary) hypertension |
| E11.9 | Type 2 diabetes without complications |
| J18.9 | Pneumonia, organism not specified |
Outpatient procedures and visits are billed with a different set, CPT codes, while hospital payment groups are called DRGs.
Less common clinical meanings of ICD
In the UK, Australia and some other countries, ICD often means intercostal drain, the tube placed between the ribs to drain air or fluid from around the lung. US notes usually call this a chest tube. In dermatology, ICD can mean irritant contact dermatitis, a skin rash caused by direct damage from soaps, solvents or frequent hand washing, as opposed to allergic contact dermatitis.
A note about the lungs or a collapsed lung that says "ICD in situ" is talking about a drain, not a heart device. When the setting does not settle it, the author of the note can clarify.
ICD abbreviation medical tips for students
Coding and scribe students meet ICD as a code set on day one, while nursing students meet it as a device on telemetry floors. A quick test is to look for numbers: a code like I50.22 is a diagnosis code, while words such as interrogation, leads, shocks or generator point to the device.
Find more device and procedure shorthand on the surgery and procedures hub.
Device settings, driving advice and the meaning of any code on your own records are best explained by your cardiology team or the billing office that issued them.
Frequently asked questions
What does ICD mean in cardiology?
It means implantable cardioverter defibrillator, a device placed under the skin that monitors the heart and can shock or pace it out of a dangerous fast rhythm.
Is an ICD the same as a pacemaker?
Not exactly. A pacemaker treats slow heartbeats by pacing, while an ICD can also shock dangerous fast rhythms. Most ICDs include pacemaker functions as well.
Is AICD the same as ICD?
Yes, in practice. AICD, automatic implantable cardioverter defibrillator, is an older name for the same kind of device, and many charts still use it.
What is an ICD code?
It is a code from the International Classification of Diseases that stands for a specific diagnosis or condition. Codes appear on claims, problem lists and visit summaries.
What does ICD mean on a chest x-ray report?
In UK and Australian reports it often means intercostal drain, a chest tube between the ribs. In US reports, ICD is more likely to mean a defibrillator seen on the image.