1. Apparatus for graphical representation of a train of ECG complexes, said ECG complexes comprising an R wave and a T-P interval and having variable isoelectric baselines, the apparatus comprising: an isoelectric alignment unit for aligning said complexes by obtaining a baseline based on irregular sampling of said baseline, thereby to provide a graphical representation of said train of ECG complexes; and a temporal alignment unit for aligning said complexes temporally using a predetermined point of respective complexes.