The Heart Sounds &
Murmurs Laboratory Lab Director: James M. Wilson, MD
The following videos were recorded as part of Dr. Wilson's lectures. We strongly recommend that you
use headphones for listening to recorded heart sounds rather than through loudspeakers. If you don't
have access to headphones, however, Dr. Michael Nihill, a pediatric Cardiologist at Texas Children's
Hospital, suggests that you use your stethoscope pressed against a loudspeaker as an alternative.
Another recommendation is repetition. Studies have shown that in order to improve auscultatory skills,
repetition is the key. So listen to the sounds over and over again (read abstract below).
We must seek out normal and abnormal sounds and murmurs rather than waiting for them to announce themselves. Perhaps the most difficult skill to
acquire is separating distinct sounds and describing their timing and character. A loud systolic murmur may be easy to identify. By habit, we almost
automatically place all action in systole, but to describe when in systole the murmur occurs requires a bit of practice. You must listen to the murmur and
only the murmur in several locations. You then listen to the distinct and separate normal or expected sounds to determine the timing as midsystolic or
holosystolic. Perhaps it is continuous and not really just a systolic murmur. You must seek out additional sounds that may be hiding within the murmur, for
example, an ejection sound of a bicuspid aortic valve. Without this effort to listen for distinct sounds and their timing, a correct diagnosis from the
physical examination will be elusive.
When you examine a sound or murmur, ask four (4) questions to help you determine theri origin.
Ask when, where, with whom, and what pitch?
1). When do you hear the sound? During systole, diastole, early, mid, or late?
2). Where can you hear the sound or murmur most easily?
3). With whom is perhaps the most important question. Where else (at what other locations) can you hear the sound or murmur (radiation)? What other
sounds or murmurs are also present? Many times a diagnosis rests not on the character of a particular sound but on the company it keeps. For example,
you may notice a similarity between the widely radiating pericardial knock and an opening snap of mild mitral stenosis. When you encounter the extra
sound, careful examination in the left lateral decubitus position will expose the murmur of mitral stenosis. Meanwhile, close inspection of the precordium
and neck veins may uncover the company kept by a pericardial knock.
4). The fourth question is about pitch; murmurs or sounds in the high frequency range such as valve closure sounds, clicks, or the murmur of mitral
regurgitation are heard best with the diaphragm. Conversely, low frequency sounds or murmurs such as the S3 or the murmur of mitral stenosis are more
easily heard with the bell.