Other conduction disorders (I45) ICD-10-CM
The I45 code range covers other conduction disorders with 14 ICD-10-CM diagnosis codes. 11 of them are billable and valid for claim submission in fiscal year 2026, and the category headers group them but cannot themselves be billed.
Codes in the I45 Range 14 codes · 11 billable
- I45 Other conduction disordersNon-billable
- I45.0 Right fascicular block
- I45.1 Other and unspecified right bundle-branch blockNon-billable
- I45.10 Unspecified right bundle-branch block
- I45.19 Other right bundle-branch block
- I45.2 Bifascicular block
- I45.3 Trifascicular block
- I45.4 Nonspecific intraventricular block
- I45.5 Other specified heart block
- I45.6 Pre-excitation syndrome
- I45.8 Other specified conduction disordersNon-billable
- I45.81 Long QT syndrome
- I45.89 Other specified conduction disorders
- I45.9 Conduction disorder, unspecified
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the I45 range.
Andersen Syndrome
A form of inherited long QT syndrome (or LQT7) that is characterized by a triad of potassium-sensitive periodic paralysis, VENTRICULAR ECTOPIC BEATS, and abnormal features such as short stature, low-set ears, and SCOLIOSIS. It results from mutations of KCNJ2 gene which encodes a channel protein (INWARD RECTIFIER POTASSIUM CHANNELS) that regulates resting membrane potential.
Heart Block
Impaired conduction of cardiac impulse that can occur anywhere along the conduction pathway, such as between the SINOATRIAL NODE and the right atrium (SA block) or between atria and ventricles (AV block). Heart blocks can be classified by the duration, frequency, or completeness of conduction block. Reversibility depends on the degree of structural or functional defects.
Long QT Syndrome
A condition that is characterized by episodes of fainting (SYNCOPE) and varying degree of ventricular arrhythmia as indicated by the prolonged QT interval. The inherited forms are caused by mutation of genes encoding cardiac ion channel proteins. The two major forms are ROMANO-WARD SYNDROME and JERVELL-LANGE NIELSEN SYNDROME.
Romano-Ward Syndrome
A form of long QT syndrome that is without congenital deafness. It is caused by mutation of the KCNQ1 gene which encodes a protein in the VOLTAGE-GATED POTASSIUM CHANNEL.
Sinoatrial Block
Disturbance in the atrial activation that is caused by transient failure of impulse conduction from the SINOATRIAL NODE to the HEART ATRIA. It is characterized by a delayed in heartbeat and pauses between P waves in an ELECTROCARDIOGRAM.
About the I45 Code Range
The ICD-10 code section I45 covers various "Other conduction disorders" of the heart, including blocks and syndromes affecting the heart's electrical pathways. These codes identify specific types of conduction abnormalities such as right fascicular block (I45.0), bifascicular block (I45.2), and nonspecific intraventricular block (I45.4), among others.
This section is used to classify heart rhythm and conduction conditions that do not fall within the common bundle branch blocks or AV blocks. For example, I45.10 represents the unspecified right bundle-branch block and includes synonyms like "Brugada electrocardiograph pattern" and "EKG: right bundle branch block," assisting coders in linking various medical terms to the correct code. Codes like I45.6 cover pre-excitation syndromes, such as Wolff-Parkinson-White syndrome, reflecting abnormal electrical conduction pathways that can cause rapid heart rhythms. The code I45.81 denotes Long QT syndrome, which has multiple subtypes and is known by names including "Romano-Ward syndrome" and "Jervell and Lange-Nielsen syndrome." Detailed coding within this section helps pinpoint the precise conduction disorder for accurate diagnosis and treatment documentation.
Questions About This Page
How many billable codes are in the I45 range?
Of the 14 codes in this range, 11 are billable and valid for claim submission from October 1, 2025 through September 30, 2026. Category header codes group them but cannot be reported on claims.
What does the I45 range classify?
The range classifies other conduction disorders. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.
