A method of operating a hearing system comprising a first hearing device and an accessory device is dislosed, the method comprising: obtaining sensor data, the sensor data comprising first sensor data indicative of a first sensor signal from the first hearing device arranged at a first ear of a user; detecting an atrial fibrillation condition of the user based on the first sensor data; and in accordance with detecting the atrial fibrillation condition, outputting a first output signal indicative of the atrial fibrillation condition.