On 5/25, M6221 was dispatched on an upgrade as the 2nd ALS unit for a cardiac arrest in Leesburg. Co 13 arrived on scene to find a working code. M6221 arrived shortly thereafter and immediately proceeded into the house to find a 91 year old female unconscious & in full cardiac arrest. M6221 set up the Lucas device, established an IV, intubated the patient and pushed medications. After ventilating the patient for several minutes, and after the medications had been administered, the crew of M6221 noticed that the patient was again breathing on her own. The patient was delivered to the ER with a palpable pulse and breathing on her own. Great job by all crew members of M6221!