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Appendix D Recording Techniques
1. The room should be quiet. Most of the problems with recording heart sounds result from not
having the room quiet and from lack of practice. Before attempting to record a patient, do several
test recordings until proficiency is obtained.
2. The patient should be relaxed as much as possible.
3. For a thorough examination, the patient should be in a sitting, lying and left lateral recumbent
position. For an adequate examination, the recumbent position alone can be used, but listening to
the heart with the patient only in a sitting position is absolutely inadequate. Typical diastolic murmurs
of good intensity that are heard when the patient is in the recumbent position may NOT be heard at
all when the patient is sitting. In the recumbent position, the patient’s arms must not be held over
the head, since this will elevate the rib cage and decrease the intensity of the heart sound.
Occasionally, it is of advantage to listen with the patient in the prone position; this may be true in
patients with deep chests or those who may have a friction rub. This position may be awkward
when the patient is in bed or on the examining table and supporting himself/herself on the
elbows. It is much more satisfactory to have the patient stand up and lean over with his/her
elbows on an examining table. Muscle noise is at a minimum in this position and the patient and
examiner are much more comfortable. An important additional advantage of this position is that
the patient can be made to exercise by touching his toes several times before he assumes the
position.
4. When the bell of the stethoscope is applied to the skin, the enclosed skin forms a
diaphragm. With increased pressure, the skin diaphragm is made more taut and its natural period
of oscillation increases. This improves the response to higher pitches and at the same time there
is a general lowering of the sensitivity of the skin diaphragm. As a result, the lower-frequency
components of the heart sounds are attenuated, whereas the higher frequencies are still well heard.
This important maneuver of being able to diminish the intensity of low-pitched sounds, by pressure
on the bell has several implications and applications:
a. To hear faint, low-pitched sounds, the examiner must apply the bell lightly to the chest wall.
