Ivan Co, Wesley Eilbert, Terry Chiganos

The electronic medical record is a relatively new technology that allows quick review of patients' previous medical records, including previous electrocardiograms (ECGs). Previous studies have evaluated ECG patterns predictive of pulmonary embolism (PE) at the time of PE diagnosis, though none have examined ECG changes in these patients when compared with their previous ECGs. Our aim was to identify the most common ECG changes in patients with known PE when their ECGs were compared with their previous ECGs. A retrospective chart review of patients diagnosed with PE in the emergency department was performed. Each patient's presenting ECG was compared with their most recent ECG obtained before diagnosis of PE. A total of 352 cases were reviewed. New T wave inversions, commonly in the inferior leads, were the most common change found, occurring in 34.4% of cases. New T wave flattening, also most commonly in the inferior leads, was the second most common change, occurring in 29.5%. A new sinus tachycardia occurred in 27.3% of cases. In 24.1% of patients, no new ECG changes were noted, with this finding more likely to occur in patients younger than 60 years. The most common ECG changes when compared with previous ECG in the setting of PE are T wave inversion and flattening, most commonly in the inferior leads, and occurring in approximately one-third of cases. Approximately one-quarter of patients will have a new sinus tachycardia, and approximately one-quarter will have no change in their ECG.