An arrhythmia monitoring device includes a plurality of pairs of ECG sensing electrodes disposed in a garment configured to be worn about a torso of a patient, and signal acquisition circuit configured to be electrically coupled to the plurality pairs of ECG sensing electrodes. The device includes a processor in communication with the signal acquisition circuit configured to execute a selection process comprising identifying a quality of each of a plurality of ECG signals, ranking the signals based on the identified quality, and selecting at least two ECG signals to monitor having highest quality. The processor is configured to re-execute the selection process following an event including at least one of the garment shifting on the torso, the garment being repositioned on the torso, and the garment being removed and returned to the torso of the patient, and monitor the selected at least two ECG signals for a cardiac arrhythmia.