ICD-10 Code I45.4 – Nonspecific intraventricular block (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I45.4 – Nonspecific intraventricular block
What it is
Nonspecific intraventricular block is a conduction delay within the heart’s ventricles that does not fit a more specific bundle branch block pattern. It means the QRS is widened or abnormal on ECG, but the exact pathway is not clearly defined.
Clinical signs
Clinical features vary; refer to documentation. It is usually identified on electrocardiogram, sometimes with a widened QRS complex and abnormal ventricular conduction pattern, without criteria for a specific bundle branch block.
When to use this code
Use I45.4 when the provider documents nonspecific intraventricular block, intraventricular conduction delay, or a similar non-specific ventricular conduction abnormality. Code it when the ECG finding is confirmed and no more specific conduction disorder is documented. Check documentation if the record also mentions bundle branch block or other rhythm diagnoses.
Do not use for
Do not use this code for left bundle branch block, right bundle branch block, or other specifically named conduction defects. If the documentation is unclear or conflicting, check documentation before assigning a code.
Coding tip
Assign the most specific conduction diagnosis documented; if the ECG wording is vague, query the provider rather than assuming I45.4.