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 2027, 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.
Bifascicular Block by ECG Finding
An electrocardiographic finding comprising right bundle branch block and left anterior fascicular block, or right bundle branch block and left posterior fascicular block. Defects occurring in two of the three divisions of the conduction system of the heart are considered bifascicular blocks. Technically left bundle branch block may be considered a bifascicular block.
Cardiac Conduction Disorder
A disorder affecting the conduction system that sends electrical signals in the myocardium.
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.
Pre-Excitation Syndromes
A group of conditions in which HEART VENTRICLE activation by the atrial impulse is faster than the normal impulse conduction from the SINOATRIAL NODE. In these pre-excitation syndromes, atrial impulses often bypass the ATRIOVENTRICULAR NODE delay and travel via ACCESSORY CONDUCTING PATHWAYS connecting the atrium directly to the BUNDLE OF HIS.
About the I45 Code Range
Heart conduction disorders include forms of heart block, pre-excitation syndrome, and long QT syndrome.
The subdivisions distinguish right fascicular block (I45.0) from right bundle-branch block (I45.1), which splits into unspecified and other types. Separate codes identify bifascicular block (I45.2), trifascicular block (I45.3), nonspecific intraventricular block (I45.4), and other specified heart block (I45.5).
Pre-excitation syndrome has its own code, I45.6. Other specified conduction disorders (I45.8) split into long QT syndrome and other specified disorders. I45.9 identifies an unspecified conduction disorder.
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, 2026 through September 30, 2027. 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 2027 ICD-10-CM Tabular List and order file, effective October 1, 2026 through September 30, 2027.
