Patient characteristics
We identified a total of 5,035 12-lead ECGs for inpatients between November 23rd, 2019 and January 31st, 2020. We excluded ECG orders that were duplicated or canceled, those that were not within the fourteen-day timeframe, those with missing follow-up readings, and those not in sinus rhythm (i.e., atrial fibrillation, atrial flutter, sinus tachycardia, and others). This resulted in a total of 324 12-lead ECGs reviewed for a total of 148 unique patients, as shown in figure 1.