arrhythmia

DEFINITION of arrhythmia

An arrhythmia (also known as dysrhythmia) refers to any disturbance in the rate, rhythm, origin, or conduction of the electrical impulses of the heart. It occurs when the electrical signals that coordinate the heart’s beats do not work properly, causing the heart to beat too fast, too slow, or erratically. While some arrhythmias are harmless, others can be life-threatening by disrupting the heart’s ability to pump blood effectively to the body.

3. Related Terms & Synonyms

• Dysrhythmia: Often used interchangeably with arrhythmia (technically “bad rhythm” vs “no rhythm,” but clinically synonymous).
• Tachycardia: Heart rate > 100 beats per minute (resting).
• Bradycardia: Heart rate < 60 beats per minute
• Fibrillation: Rapid, irregular, and unsynchronized contraction of muscle fibers (e.g., Atrial Fibrillation).
• Palpitations: The sensation of the heart racing, pounding, fluttering, or skipping a beat.
• Premature Ventricular Contraction (PVC): Extra, abnormal heartbeats that begin in one of the heart’s two lower pumping chambers (ventricles).

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ETYMOLOGY of arrhythmia

greek

• Origin: Late 19th century.
• Roots: From Greek arrhythmia (“want of rhythm”).
• Breakdown: a- (without, not) + rhythmos (rhythm).
• Historical Context: Originally used to describe any lack of rhythm in verse or music before being adopted into medical terminology to describe the pulse.

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Coding Corner

ICD-10-CM (Diagnosis Codes)

Arrhythmias are classified primarily under Chapter 9: Diseases of the Circulatory System (I00-I99).

Category I48: Atrial fibrillation and flutter

• I48.0: Paroxysmal atrial fibrillation
• I48.2: Chronic atrial fibrillation
• I48.91: Unspecified atrial fibrillation

Category I49: Other cardiac arrhythmias

• I49.01: Ventricular fibrillation
• I49.1: Atrial premature depolarization
• I49.3: Ventricular premature depolarization
• I49.9: Cardiac arrhythmia, unspecified

Symptom Codes (if no definitive diagnosis):

• R00.0: Tachycardia, unspecified
• R00.1: Bradycardia, unspecified
• R00.2: Palpitations

CPT (Procedure Codes)

Diagnostic and treatment codes vary widely.

• 93000: Electrocardiogram (EKG/ECG), routine ECG with at least 12 leads; with interpretation and report.
• 93224: External electrocardiographic recording up to 48 hours (Holter monitor); includes recording, scanning analysis, and report.
• 93653: Comprehensive electrophysiologic evaluation with insertion and repositioning of multiple electrode catheters… includes ablation (treatment for SVT).
• 92960: Cardioversion, elective, electrical conversion of arrhythmia; external.

5. ICD-10 Guidelines: Includes & Excludes

Includes (Category I49):

• Ectopic beats
• Extrasystoles
• Co-occurrences of specific rhythm disorders

Excludes1 (Type 1 Excludes - NEVER code together):

• Bradycardia NOS (R00.1)
• Neonatal dysrhythmia (P29.1)
• Tachycardia NOS (R00.0)

Excludes2 (Type 2 Excludes - Can be coded together if distinct):

• Cardiac arrhythmias complicating abortion, ectopic or molar pregnancy (O00-O07, O08.8)
• Cardiac arrhythmias complicating pregnancy, childbirth and the puerperium (O99.4)

6. Reimbursement & Administrative Data

HCC (Hierarchical Condition Category)

• Atrial Fibrillation (I48.x): Maps to HCC 96 (Specified Heart Arrhythmias). This is a high-value code for risk adjustment due to the chronic management and stroke risk involved.
• Ventricular Fibrillation (I49.01): Maps to HCC 96.
• Unspecified Arrhythmia (I49.9): Generally does NOT map to an HCC. Specificity is required for risk adjustment credit.
• Palpitations (R00.2): Does NOT map to an HCC (Symptom code).

Assistant Surgeon Pay

• Diagnostic (EKG 93000): No. (Technical/professional component only).

• Cardioversion (92960): No. (Minor procedure).

• Ablation/EP Studies (93653): Sometimes.

  • Complex Electrophysiology (EP) studies often require a second pair of hands, but policies vary by payer.

• Pacemaker Implantation (33206-33208): No. (Generally considered a single-surgeon procedure unless complications arise or it is a distinct complex scenario).

• MAZE Procedure (Surgical Ablation 33254): Yes. (Open heart surgery for arrhythmia usually allows for assistant surgeon billing).

7. Clinical Details

Pathophysiology

The heart’s rhythm is controlled by the sinoatrial (SA) node (the natural pacemaker).

1. SA Node Failure: The pacemaker fails to fire or fires irregularly.
2. Conduction Block: The electrical signal is blocked at the AV node or bundle branches.
3. Ectopic Foci: Other parts of the heart (atria or ventricles) start firing their own electrical signals, overriding the SA node.
4. Re-entry: An electrical impulse travels in a circle within the heart, causing a rapid rhythm.

Common Types

• Atrial Fibrillation (AFib): The upper chambers beat chaotically. Risk of stroke due to blood clots.
• Supraventricular Tachycardia (SVT): Rapid heartbeat beginning above the ventricles.
• Ventricular Tachycardia (V-tach): Rapid heartbeat beginning in the lower chambers; can be fatal if sustained.
• Heart Block: Electrical signals are slowed or blocked.

Symptoms

• Fluttering in the chest.
• Racing heartbeat (tachycardia) or slow heartbeat (bradycardia).
• Chest pain.
• Shortness of breath.
• Lightheadedness or dizziness.
• Syncope (fainting).

Treatment

• Medication: Anti-arrhythmics (e.g., Amiodarone, Beta-blockers, Calcium channel blockers) and Anticoagulants (blood thinners for AFib).
• Cardioversion: Using electricity or drugs to reset the heart rhythm.
• Catheter Ablation: Destroying the small area of heart tissue causing the abnormal signals.
• Device Therapy:
  • Pacemaker: For bradycardia.
  • ICD (Implantable Cardioverter Defibrillator): For life-threatening ventricular arrhythmias.

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A Word from MedlinePlus

An arrhythmia is a disorder of the heart rate (pulse) or heart rhythm. The heart can beat too fast (tachycardia), too slow (bradycardia), or irregularly.

An arrhythmia can be harmless, a sign of other heart problems, or an immediate danger to your health.

Causes

Normally, your heart works as a pump that brings blood to the lungs and the rest of the body.

To help this happen, your heart has an electrical system that makes sure it contracts (squeezes) in an orderly way.

• The electrical impulse that signals your heart to contract begins in an area of the heart called the sinoatrial node (also called the sinus node or SA node). This is your heart’s natural pacemaker.
• The signal leaves the SA node and travels through the heart along a set electrical pathway.
• Different nerve messages signal your heart to beat slower or faster.

Arrhythmias are caused by problems with the heart’s electrical conduction system.

• Abnormal extra signals may occur.
• Electrical signals may be blocked or slowed.
• Electrical signals travel in new or different pathways through the heart.

Some common causes of abnormal heartbeats are:

• Abnormal levels of potassium, magnesium, or other substances in the body
• Heart attack, or a damaged heart muscle from a past heart attack
• Heart disease that is present at birth (congenital)
• Heart failure or an enlarged heart
• Overactive thyroid gland

Watch this video about:Arrhythmias

Arrhythmias may also be caused by some substances or drugs, including:

• Alcohol or stimulant drugs
• Certain medicines
• Cigarette smoking (nicotine)

Some of the more common abnormal heart rhythms are:

• Atrial fibrillation or flutter
• Atrioventricular nodal reentry tachycardia (AVNRT)
• Heart block or atrioventricular block
• Multifocal atrial tachycardia
• Paroxysmal supraventricular tachycardia
• Sick sinus syndrome
• Ventricular fibrillation or ventricular tachycardia
• Wolff-Parkinson-White syndrome

Symptoms

When you have an arrhythmia, your heartbeat may be:

• Too slow (bradycardia)
• Too quick (tachycardia)
• Irregular, uneven, possibly with extra or skipped beats

An arrhythmia may be present all of the time or it may come and go. You may or may not feel symptoms when the arrhythmia is present. Or, you may only notice symptoms when you are more active.

Symptoms can be very mild, or they may be severe or even life threatening.

Common symptoms that may occur when the arrhythmia is present could include:

• Chest pain
• Fainting
• Lightheadedness, dizziness
• Paleness
• Palpitations (feeling your heart beat fast or irregularly)
• Shortness of breath
• Sweating

Exams and Tests

The health care provider will listen to your heart with a stethoscope and feel your pulse. Your blood pressure may be low or normal or even high as a result of being uncomfortable.

An electrocardiogram (ECG) will be the first test done.

Heart monitoring devices are often used to identify the rhythm problem, such as a:

• Holter monitor (where you wear a device that records and stores your heart rhythm for 24 or more hours)
• Event monitor or loop recorder (worn for 2 weeks or longer, where you record your heart rhythm when you feel an abnormal rhythm)
• Other long-term monitoring options

An echocardiogram is sometimes ordered to examine the size or structure of your heart.

In selected cases, coronary angiography may be performed to see how blood flows through the arteries in your heart.

A special test, called an electrophysiology study (EPS), is sometimes done to take a closer look at the heart’s electrical system.

Treatment

When an arrhythmia is serious, you may need urgent treatment to restore a normal rhythm. This may include:

• Electrical therapy (defibrillation or cardioversion)
• Implanting a short-term heart pacemaker
• Medicines given through a vein or by mouth

Sometimes, better treatment for your angina or heart failure will lower your chance of having an arrhythmia.

Medicines called anti-arrhythmic drugs may be used:

• To prevent an arrhythmia from happening again
• To keep your heart rate from becoming too fast or too slow

Some of these medicines can have side effects. Take them as prescribed by your provider. Do not stop taking the medicine or change the dose without first talking to your provider.

Other treatments to prevent or treat abnormal heart rhythms include:

• Cardiac ablation, used to target areas in your heart that may be causing your heart rhythm problems
• An implantable cardioverter defibrillator, placed in people who are at high risk of sudden cardiac death
• Permanent pacemaker, a device that senses when your heart is beating too slowly. It sends a signal to your heart that makes your heart beat at the correct pace.

Outlook (Prognosis)

The outcome depends on several factors:

• The kind of arrhythmia you have.
• Whether you have coronary artery disease, heart failure, or valvular heart disease.

When to Contact a Medical Professional

Contact your provider if:

• You develop any of the symptoms of a possible arrhythmia.
• You have been diagnosed with an arrhythmia and your symptoms worsen or do not improve with treatment.

Prevention

Taking steps to prevent coronary artery disease may reduce your chance of developing an arrhythmia.

Alternative Names

Abnormal heart rhythms; Bradycardia; Tachycardia; Fibrillation

References

Al-Khatib SM, Stevenson WG, Ackerman MJ, et al. 2017 AHA/ACC/HRS guideline for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death: Executive summary: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society. Heart Rhythm. 2018;15(10):e190-e252. PMID: 29097320 pubmed.ncbi.nlm.nih.gov/29097320/.

Nattel S, Tomaselli GF. Mechanisms of cardiac arrhythmias. In: Libby P, Bonow RO, Mann DL, Tomaselli GF, Bhatt DL, Solomon SD, eds. Braunwald’s Heart Disease: A Textbook of Cardiovascular Medicine. 12th ed. Philadelphia, PA: Elsevier; 2022:chap 62.

Olgin JE. Approach to the patient with suspected arrhythmia. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 49.

Tracy CM, Epstein AE, Darbar D, et al. 2012 ACCF/AHA/HRS focused update of the 2008 guidelines for device-based therapy of cardiac rhythm abnormalities: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol. 2012;60(14):1297-1313. PMID: 22975230 pubmed.ncbi.nlm.nih.gov/22975230/.

Review Date 5/27/2024

Updated by: Michael A. Chen, MD, PhD, Associate Professor of Medicine, Division of Cardiology, Harborview Medical Center, University of Washington Medical School, Seattle, WA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

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DERIVATIONS of arrhythmia

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Med roots Appendix A Prefixes Appendix B Combining Forms Appendix C Suffixes Appendix D Suffix forms