Question: What’s our ICD-10 coding option if the cardiologist documents a bifascicular block? New Hampshire Subscriber Answer: To report bifascicular block you should look to I45.2 (Bifascicular block). Bifascicular block defined: After the heart’s electrical impulse passes through the AV node (between the atria and ventricles), the impulse passes along the bundle of His, which divides into a right bundle and a left bundle. The left bundle branches into a left posterior fascicle and a left anterior fascicle. Bifascicular block means the heart shows impaired conduction in two fascicles of the right and left bundles. Documentation: The physician needs to indicate that the block is bifascicular, as that is the key indicator for code I45.2.