Repetition helps med students master heart sounds
Repetition appears to be key in improving medical students’ woeful lack of stethoscope skills, a handicap that often continues into patient practice. A new study in the January issue of the American Journal of Medicine shows that when medical students listened to heart sounds up to 500 times, they significantly honed their ability to identify specific problems such as a heart murmur or heart failure.
Long bothered by this lack of proficiency with the stethoscope, lead author Michael Barrett, clinical associate professor of medicine and cardiologist at the School of Medicine and Temple University Hospital, said such skills are critical to identifying dangerous heart conditions and minimizing dependence on expensive medical tests.
“It’s important to know when to order a costly echocardiogram or stress test. Managed care will not continue to tolerate this scattershot approach,” Barrett said. “Plus, internists are now tested on this skill for board recertification. Requirements for residents and other specialists are sure to follow.”
In previous studies, the rate of accurate heart sound identification ranged from 20 percent of medical students to fewer than 40 percent of internists. Traditional teaching methods for stethoscope skills — classroom lectures — have proven inadequate.
Photo by Kelly & Massa
Michael Barrett (left) and cardiology fellow,Behnam Bozorgnia operate an electronic stethoscope, which simulates patients’ heart sounds. “For your brain to recognize a sound, you need to listen to it hundreds of times. Thereafter, the sound is locked in as a template,” Barrett explained.
“We hypothesized that cardiac auscultation is more of a technical skill and thus could be mastered through the use of intensive repetition,” Barrett said.
For the study, 80 third-year medical students listened to an average of 500 repetitions each of six abnormal heart sounds (aortic stenosis, aortic regurgitation, mitral regurgitation, mitral stenosis and S3 and S4 gallops) that mimicked heart conditions, such as narrowing of the heart valves and heart failure. The researchers gave CDs to the students, who typically converted the sounds to MP3 files so they could listen on their iPods.
With repetition, proficiency improved from approximately 39 percent to 89 percent. Students in the control group, who did not undergo the repetition, showed no improvement.
Currently, Barrett is studying the impact of electronic stethoscopes as patient simulators on residents’ abilities to accurately identify specific heart sounds. He will report his preliminary findings at the American College of Cardiology meeting in Atlanta in March.
Barrett, director of the Fellows Cardiac Clinic at Temple University Hospital, has published more than 40 articles on cardiac auscultation and echocardiography.