Abstract: A system for interpreting electrocardiograms receives a first electrocardiogram waveform, and identifies a feature in the first electrocardiogram waveform. The system retrieves one or more second electrocardiogram waveforms recorded at a point in time prior to the first electrocardiogram waveform. The system extracts the feature from the one or more second electrocardiogram waveforms, and generates one or more interpretive statements based on a comparison of the feature identified in the first electrocardiogram and the feature extracted from the one or more second electrocardiogram waveforms.