Abstract: A method of processing of electrocardiogram includes the steps of providing an electrocardiogram comprising signals in at least two channels; selecting at least two frequency ranges of the signal in each of the said at least two channels; calculating an envelope for the signal in each frequency range in each channel; dividing the calculated envelope of the signal in each frequency range in each channel into QRS complex segment envelopes; and computing an average or median envelope as an average or mean of QRS complex segment envelopes for each frequency range in each channel.