ED Coding and Reimbursement Alert

Question: I am stumped on diagnosis coding for the following  encounter. Notes indicate that the ED physician treated a patient suffering from an -AV block.- What is an AV block, and what is the proper ICD-9 code for the patient's condition?


California Subscriber

Answer: When the electrical signal does not transmit correctly from the atria to the ventricles via the atrioventricular (AV) node, the condition is called an AV block. 

You will choose the diagnosis code based on the patient's level of impairment:

First-degree AV blocks occur when the electrical signal still passes through the AV node--just more slowly than normal, meaning a PR (the distance between the P wave and the R wave) interval greater than 0.2 seconds on an electrocardiogram (ECG). For most first-degree AV blocks, report 426.11 (First-degree atrioventricular block).

If, however, the ED physician identifies a partial or incomplete AV block but does not specify the degree, report 426.10 (Atrioventricular block, unspecified).

Second-degree AV blocks happen when some electrical signals get through the AV node and others don-t, which results in -dropped beats.- There are two types of second-degree blocks--Mobitz type II, which you-ll code with 426.12 (Mobitz [type] II atrioventricular block); and Mobitz type I, which you-ll represent with 426.13 (Other second-degree atrioventricular block).

Also use 426.13 if the notes indicate a second-degree AV block not otherwise specified (NOS). 

Third-degree AV blocks are also known as complete blocks. These occur when the signal doesn't pass at all from the atria to the ventricles. This shows up on an ECG as the lack of a normal relationship between the P (atrial) and QRS (ventricular) waves. The ICD-9 code for this block is 426.0 (Atrioventricular block, complete).