A medical signal processing system for processing medical signal data obtained from a human or animal heart, and displaying a graphical representation of the processed data for providing an alert, the system including: a medical signal data input for inputting one or more ECG signals a graphical display and a signal processor coupled to said data input and to said display and wherein said signal processor is configured to: input medical signal data associated with a spatial position in or on said organ perform at least one measurement relating to said organ using said medical signal data to provide measurement data determine from said measurement data whether said measurement is normal or abnormal and display, on a graphical representation of said heart, a graphical indication of an abnormality at said spatial position on a wall of said heart with which said signal data is associated responsive an abnormal to said determination.
