Atrioventricular block, first degree

First-degree atrioventricular (AV) block is a benign cardiac conduction abnormality characterized by a prolonged PR interval on an electrocardiogram (ECG). This indicates a delay in electrical impulse conduction from the atria to the ventricles, but all atrial impulses are still conducted. It typically does not cause symptoms and is often an incidental finding.

This code is appropriate when ECG findings demonstrate a consistent PR interval greater than 0.20 seconds, with every P wave followed by a QRS complex. It is commonly identified during routine physical examinations, pre-operative assessments, or workups for other cardiac conditions. Documentation should explicitly state "first-degree AV block" or describe the characteristic ECG findings.

• Do not confuse this with higher degrees of AV block (e.g., second-degree or third-degree), which have distinct clinical implications and different codes.
• This code is often a secondary diagnosis, as it is usually asymptomatic and discovered during evaluation for other conditions.
• Ensure the medical record clearly documents the ECG interpretation supporting the diagnosis of first-degree AV block.