For a busy clinician in the Emergency Department, the ability to spot a lethal cardiac condition is critical. Fills a gap in ECG training in an easy-to-use, highly visual format. ECG patterns, gathered from patient records and from the files of physicians at the Harvard-affiliated hospitals, represent the range of pathologies that hospitalists, internal medicine physicians, family medicine physicians, and emergency medicine physicians must recognize. The format of is to first show an ECG in its native state to give you the chance to recognize and interpret salient features. The page can then be flipped to look at the same ECG with abnormal patterns enlarged, highlighted in color, and described in brief text. The ECGs are presented with and without annotations so you can test your diagnostic skills.