INSERTABLE CARDIAC MONITORING DEVICE DESIGNED FOR THE MRI ENVIRONMENT

An apparatus comprises a magnetic field detection circuit, a cardiac signal sensing circuit, a memory circuit, a control circuit, and an arrhythmia detection circuit. The cardiac signal sensing circuit generates a cardiac signal representative of cardiac activity of a subject when coupled to sensing electrodes. The control circuit is operatively coupled to the magnetic field detection circuit; the cardiac signal sensing circuit, and the memory circuit. The control circuit stores cardiac signal data determined using the sensed cardiac signal, receives an indication of magnetic field detection by the magnetic field detection circuit, stores data obtained using the sensed cardiac signal during the magnetic field detection, and stores an identifier indicating the magnetic field detection in association with the data. The arrhythmia detection circuit processes the cardiac signal data to detect a cardiac arrhythmia event and confirm the cardiac arrhythmia event according to the magnetic field indication.