Mastering cardiac murmurs: the power of repetition.

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.