An ECG analysis system is responsive to patient ECG data for performing an analysis of the ECG data to determine whether acute MI is present. The system first analyzes the ECG data by standard ECG analysis to determine whether acute MI is present. This analysis is followed in a first mode of operation by ACI-TIPI analysis to estimate the probability of acute MI from patient characteristics and the ECG data. In a second mode, when the standard ECG analysis is definitive as to the presence of acute MI the ACI-TIPI analysis is not run and the user is presented with only the results of the standard interpretation. If the standard ECG analysis is indeterminate as to the presence of acute MI, then the ACI-TIPI analysis is run and the results of the ACI-TIPI analysis are presented to the user.