The purpose of this study was to assess the usefulness of the time-axis variable function of the digital stethoscope in teaching cardiac auscultation. The subjects were 61 fifth-year medical students. The effectiveness of the time-axis variable function of the digital stethoscope for cardiac auscultation was assessed with five representative heart sounds or murmurs. The students reported that auscultatory findings were clearer at half speed than at normal speed for the following sounds, in decreasing order of frequency: systolic murmur following a systolic click, splitting of the second heart sound, systolic ejection murmur, and the third heart sound. In contrast, students frequently reported that auscultatory findings were clearer at normal speed for systolic regurgitation murmur. We suggest that the time-axis variable function is useful for improving auscultatory ability and would be particularly effective for helping students identify and understand the temporal relation of sequential heart sounds or of multicomponent murmurs.

OBJECTIVE: The purposes of this study were to assess the clinical features of cardiac auscultatory events in outpatients in general internal medicine, and to make teaching suggestions for education on cardiac auscultatory skills in primary care medicine.
METHODS: The subjects included 104 consecutive outpatients with chest symptoms, and cardiac auscultatory findings were assessed prospectively.
RESULTS: Cardiac auscultatory events were found in 32 (30.8%) among the 104 subjects. The subjects with cardiac auscultatory events were significantly older than those without cardiac auscultatory events (p<0.05) . The cardiac auscultatory events of the 32 subjects were as follows; splitting of the first heart sound in 2 subjects, mid-systolic click in 2 subjects, fourth heart sound in 3 subjects, systolic murmur in 24 subjects (including one subject with both systolic and diastolic murmurs), and diastolic murmur in 2 subjects. Aortic stenosis was diagnosed in 2 subjects, and mitral regurgitation was diagnosed in one subject of the 24 subjects with a systolic murmur. One subject with both systolic and diastolic murmurs was considered to have a relative systolic murmur with aortic regurgitation. The other 20 subjects with a systolic murmur were considered to have innocent murmurs. The 2 subjects with a diastolic murmur were diagnosed as having aortic regurgitation.
CONCLUSIONS: We suggest that the following cardiac ausculatory events should be given educational priority in primary care; 1) Fourth heart sounds as an extra heart sound. 2) Innocent murmurs: characteristics of innocent murmurs and discrimination from systolic murmurs caused by organic heart disease. 3) Systolic murmurs caused by aortic stenosis or mitral regurgitation. 4) Diastolic high-pitched murmurs caused by aortic regurgitation.