Page 13 - Read Online

Rao. Vessel Plus 2022;6:22 https://dx.doi.org/10.20517/2574-1209.2021.105 Page 3 of 24

At the start, the 1st and 2nd heart sounds, clicks, and snaps should be assessed before addressing the
murmur [5,8,9] . The auscultation should be performed over the four classic sites of auscultation such as: (1)
apex or mitral area; (2) right upper sternal border (RUSB) or aortic area; (3) left upper sternal border
(LUSB) or pulmonary area; and (4) left lower sternal border (LLSB) or tricuspid area. The left mid-sternal
border (LMSB) and a site midway between the apex and LLSB should also be utilized for auscultation. Other
areas as deemed appropriate for a given clinical scenario should also be used for auscultation. The author
prefers to utilize the eponyms, RUSB, LUSB, LLSB, apex, and LMSB, instead of aortic area, pulmonary area,
tricuspid area, mitral area, etc. The auscultation should be performed in both upright and supine positions.
Both the bell and diaphragm of the stethoscope should be used for auscultation.

After the murmur is discovered, initially determine the timing of occurrence of the murmur, namely,
systolic, diastolic, or continuous. Additional murmur timing of the diastolic murmurs to early, mid, and late
is useful (see the classification of the murmurs below). Next, the point of greatest loudness of the murmur is
appraised, if necessary, by moving the head of the stethoscope inch by inch. Any particular radiation
characteristics of the murmur are then determined. The examples are: radiation into the axilla of an apical
holosystolic murmur of mitral regurgitation (MR) and radiation from RUSB into the neck vessels of an
ejection systolic murmur of aortic stenosis (AS). By definition, radiation of murmur means that the murmur
is of equal intensity both at its origin and where it radiates to. The loudness of the murmur into grades I
[8]
through VI (Levine ) should be appraised so that a comparison between different observers during the
same visit or between examinations by the same observer at different visits [Table 1] can be made. While
grading of the murmur is routinely performed by most cardiologists, the grade of the murmur does not
indicate a given diagnosis or severity of the cardiac problem.

Descriptions such as “blowing” and others are not helpful in making a diagnosis because such descriptive
qualities have been used to characterize several heart defects. However, the depiction of the murmur’s shape
is of some value. Descriptions, namely, crescendo, decrescendo, flat, may be used to characterize the
murmur. Assessment of the pitch of the murmur is also helpful, and murmur’s pitch may be low, medium,
or high. The intensity of the murmur may vary with the respiration, and if such is present, it should be
documented. As a rule, the murmurs arising from the right side of the heart, for instance, tricuspid
regurgitation (TR), do alter with the respiratory cycle, whereas the murmurs from disturbances of the left
heart structures will not exhibit a change with respiration. Other unique murmur characteristics, for
example, multiple clicks within the patent ductus arteriosus (PDA) murmur and musical or vibratory nature
of the innocent or functional murmur, are also recorded.

Recent reviews [7,10] on auscultation suggested that mastery of skills of auscultation acquired by training and
experience is necessary to differentiate functional from pathologic murmurs, and I agree with this
assessment.

Simulation-guided cardiac auscultation via Harvey(©) mannequin or other cardiac patient simulators and
murmur online learning experience have been used to teach medical students and residents [11-14] , and such
training methods have demonstrated improvement of the overall performance of these trainees in
identifying the murmurs. While these methods are increasingly used and may be practical in the current
era, the author believes bedside acquisition of auscultatory skills under the supervision of an experienced
auscultator is important, and simulations and online material such as these and others should serve as
supplementary tools.