This retrospective, cross-sectional cohort study was conducted to investigate the novice practitioners' learning curve of visual estimation of LV ejection fraction (%) through a echocardiographic video files at the academic emergency department (ED) in tertiary urban hospital.

Eight EM residents who have no experience of echocardiography prior to the study were recruited as analysis of the echocardiographic image file. They received echocardiography interpretation skill training which included one hour of lecture. Twenty echocardiography videos files were provided during training session, they were instructed how to estimate EF by looking at the LV contractility without taking any measurement.

This procedure took less than 2 minutes in each case. An evaluation form was completed by each EP. EF is estimated qualitatively (Normal / Global hypokinesia), RWMA and quantitatively (%) by EP with echocardiographic certification(cardiologist). An each echocardiography has been performed with M7R® model ultrasound machine was reported by experienced echocardiographers as using MSM. The echocardiography results were reported blinded to our study.

A participant estimated the EF based on a complete assessment of LV wall motion including parasternal long-axis, short-axis, and apical four chamber view except for MSM.

And, participants wrote down EF(%) and a region of WMA as visual assessment and checked Normal wall motion or Global hypokinesia in EF reporting paper.

Inclusion Criteria:

• EM residents who have no experience of echocardiography

Exclusion Criteria:

• They do not want to participate this study

Eight EM residents who have no experience of echocardiography prior to the study were recruited as analysis of the echocardiographic image file.