RESUMEN
Introduction: social media is increasingly used in medical education, but its real educational effectiveness is unclear. In this study we assess the effectiveness of Twitter threads (TTS) in improving electrocardiogram (ECG) basic reading skills (ECGBRS). Materials and Methods: Seven TTS describing ECGBRS were published from October 28, 2021, to November 24, 2021. Tests were used to assess medical students ECGBRS pre and post intervention. All third and sixth-year medical students were invited to participate. Sixty-three students were enrolled (33 third year and 30 sixth year). Nine (14.3%) participants dropped out. Results: Sixth year medical students had higher ECGBRS at baseline. The number of correct items increased after the Twitter intervention; median correct pre-test items were 20 out of 56, (interquartile range (IQR) 14-23), and median post-test were 29 out of 56, (IQR 21-36) (p < 0.001). The improvement in sixth year students was greater than for third year students; 10 more correct items (IQR 4-14) vs. 7 (IQR 1-14) items (p = 0.045). The more TTS followed, the greater the improvement in ECGBRS (p = 0.004). The QRS axis calculation was the ECG reading skill with the lowest scores. Most medical students were definitely (35%) or very probably (46%) interested in repeating another on-line learning experience and found the TTS extremely (39%) or very (46%) interesting. Conclusions: The use of specifically designed TTS was associated with improvement in medical students' interpretation of ECGs. The effectiveness of the threads was higher in the final years of medical school when basic skills had already been acquired. Supplementary Information: The online version contains supplementary material available at 10.1007/s40670-023-01885-x.