Methods and devices are provided that collect intra-cardiac electrogram (EGM) signals over first and second sensing channels (channel-1 and channel-2 EGM signals, respectively) associated with an event of interest that includes a right ventricle (RV) and a left ventricle (LV), determine first, second and third global characteristics (GC) from the channel-1 and channel-2 EGM signals, and define a QRS start time within at least one of the EGM signals； and determine a threshold crossing. The methods and systems compare at least one of the first, second and third GC to the threshold crossing, select one of the first, second and third GC based on the comparing； defining a QRS end time, within at least one of the channel-1 and channel-2 EGM signals based on the one of the first, second and third GC selected, and calculate a QRS duration based on the QRS start time and QRS end time.
