Question: The cardiologist documented a typical atrial flutter. Which ICD-10 code should we report? Nebraska Subscriber Answer: For a typical atrial flutter, you should report I48.3 (Typical atrial flutter). Don’t miss: If the cardiologist had documented an atypical atrial flutter, you should instead report I48.4 (Atypical atrial flutter). And if the type of flutter was unspecified, then you should report I48.92 (Unspecified atrial flutter). Atrial flutter defined: When a patient has an atrial flutter, rapidly fired signals make the muscles in the atria contract quickly, which leads to a fast, steady heartbeat. Tip: Physicians should always document the atrial flutter as either typical or atypical. Also, make sure the physician specified atrial flutter instead of fibrillation.