The use of a dissected bovine heart to teach cardiac sonography

To create and test a dissected bovine heart model (BHM) to facilitate the interpretation of cardiac sonography (CS).

After a pretest and an instructional video on CS, emergency physicians (EPs) were randomized into two groups. Group 1 viewed two-dimensional (2D) anatomic pictures of human hearts. Group 2 examined the BHM and the same anatomic pictures as group 1. The EPs retook the pretest. The differences between the raw pretest and posttest scores of the groups were compared with an unpaired Student's t-test. Multiple linear regression was used to adjust for confounding by variation in education and initial test scores. EPs with previous experience in CS were excluded from the analysis.

Thirty-five participants met the inclusion criteria, 16 in group 1 and 19 in group 2. The groups were well balanced with respect to postgraduate year training. The EPs in group 1 had a higher average pretest score of 11.6 versus 8.1 in group 2. Compared with the pretest scores, the average improvements in group 1 and group 2 were 7.6 and 11.3 points, respectively. Group 2 improved an average of 3.7 points (95% confidence interval [95% CI] = 0.7 to 6.7; p = 0.016) more than group 1. After adjusting for confounding by the difference in initial scores, group 2 improved 1.8 (95% CI = -1.1 to 4.8; p = 0.22) more points on average than group 1.

A dissected bovine heart model did not significantly improve the ability of EPs to label structures on static ultrasounds over inspection of static-labeled anatomic pictures alone.