Mastering cardiac murmurs: The power of repetition

Abstract

Background: The ability of medical students to recognize heart murmurs is poor (20%), and does not improve with subsequent years of training. A teaching method to improve this skill would be useful. Study objectives: To determine whether intensive repetition of four basic cardiac murmurs improves auscultatory proficiency in medical students. Design: Controlled intervention study. Subjects: Fifty-one second-year medical students in an east coast medical school. Interventions: Subjects were classified into three groups: (1) a monitored group, who listened to 500 repetitions of each murmur in a monitored setting, (2) an unmonitored group, who listened to 500 repetitions of each murmur in an unmonitored setting, and (3) a control group. All three groups were tested using a pretest and posttest methodology. Measurements and results: The 20 subjects in the monitored group improved from 13.5 ± 9.8 to 85 ± 17.6% following the intervention (mean ± SD). Similarly, 21 students in the unmonitored group improved from 20.9 ± 10.9 to 86.1 ± 15.6%. Ten control students showed no significant improvement (24 ± 21.7 to 32 ± 22.5%). The differences between the two intervention groups and the control subjects was significant at p < 0.001 by analysis of variance. Conclusion: Five hundred repetitions of four basic cardiac murmurs significantly improved auscultatory proficiency in recognizing basic cardiac murmurs by medical students. These results suggest that cardiac auscultation is, in part, a technical skill.