Teaching Heart Sounds to Health Professionals

My introduction to the stethoscope came at age fifteen years. I had contracted a febrile illness and my father, a family practitioner in a small town, was listening to my heart. Rheumatic fever was endemic at that time. I was consumed with interest as to what he could be hearing. As a medical student sometime later, using a stethoscope similar to that used by my father, I was dismayed by the lack of teaching in its use. The interest that was kindled was not to be satisfied until studying at a children’s hospital four years later. My chief, a skilled auscultator, and I would daily examine some twenty patients with rheumatic fever. The findings of the softness of S1 and mitral and aortic regurgitation were commonplace, and even the Carey Coombs murmur could be occasionally elicited.

In 1951, at the time of my entrance into the practice of cardiology, in both adult and pediatric teaching hospitals, the teaching of cardiac auscultation was beginning to change. Samuel Levine’s paper on the Apical Systolic Murmur and his method of grading systolic murmurs had been published¹. Dr. Paul Wood’s book, Diseases of the Heart and Circulation², published in 1950, became my bible. Changes also had occurred in the stethoscope. Rappaport and Sprague developed a combination bell and diaphragm, with a single tube leading to each earpiece, and marketed by Hewlett Packard, which became the Cadillac of stethoscopes in the late forties. Hewlett Packard lost control of this stethoscope and the new distributor ceased production of the stethoscope, which was displaced by the Littman model, perhaps acoustically inferior but lighter, easier to use and less expensive. Further improvements were introduced in the 3M Littman and this model we see today, in a variety of colours, cast around the neck of all health care professionals, purporting knowledge of its use.

Today when the topic of cardiac auscultation is discussed, one so often hears the expression, “It’s not like it was in the old days”. This is only in part true; cardiac auscultation indeed was extremely important, there being essentially few other diagnostic aids, but present knowledge of heart sounds and available teaching methods has greatly improved. Nonetheless medical students today graduate unable to differentiate the normal from the abnormal.

The lack of cardiac auscultation skill in graduating medical students has been repeatedly demonstrated^3,4,5,6, despite programs for its improvement^4,5. Where health care professionals have no difficulty eliciting Korotkov sounds or the rumble of borborygmi, the reason for poor auscultation skill is generally considered to be the complexity of heart sounds and murmurs-too many different sounds for the brain to assimilate. Other reasons given include inadequate musical skill of the listener, variable intensity and frequency of heart sounds and murmurs within the same patient, and insensitivity of the human ear. Of interest is that there is no recommended format for the teaching of cardiac auscultation and the American Heart Association has no guidelines for this subject. Certain medical schools in North America have no teaching hours dedicated to this subject⁷. The availability of recordings of human heart sounds in computer programs^8,9 has resulted in a modest improvement in this skill deficit. This may be due to the incorporation of repeated listening, which has been shown to improve cardiac auscultatory skill¹⁰.

This lack of skill brings with it important consequences for patient care. Many patients with normal auscultatory findings are being sent for expensive investigative procedures and where seventy percent of children have a heart murmur^11,12, this problem is great. More serious however is the fact that patients with an abnormal auscultatory finding such as the aortic ejection click, are not diagnosed until the patient becomes symptomatic years later. It is incongruous that the stethoscope is the icon for being a health care provider.

Given the apparent lack of emphasis on auscultation teaching in medical school curricula, we must also ask if the actual teaching of auscultation has been effective. Are the teaching methods appropriate? Simplification of teaching by teaching only the normal, and advising referral of anything else i.e. abnormal, to a specialist possibly should help. The inference is made by some education professionals that we are tilting at windmills¹³. A closer study of the teaching of cardiac auscultation is important, searching for the answer to the core of the problem, methods to teach the student “how to listen”. The tendency is for the auscultator to listen for the tune or melody, when no tune exists, and fail to listen to the individual components of the cycle. For a sound to be musical, sound frequencies must be the same. As with a guitar string, vibration must occur. Blood does not vibrate, and therefore most heart murmurs which originate from blood turbulence are non-musical. It is the author’s belief that methods to improve the teaching of cardiac auscultation should be directed at addressing the problem of how to listen selectively to all the components of the cardiac cycle.

Music teachers have been teaching students methods of improving their listening skills for years and a search for their experience is indicated. The general impression is that one’s skill in frequency and rhythm appreciation i.e. musicality, is inborn and unchangeable. Computer programs to increase these skills ie. solfege, are available¹⁴, and definite skill improvement with their use is claimed. Communication between university music and cardiology departments is uncommon. However both disciplines must address a similar problem-musicality skill deficiency. Investigation of the methods which music departments use would seem indicated.

The word “musical” usually connotes a continuum of frequencies which occur very close together. As previously stated, blood does not vibrate, as vortices which are being shed are of different frequencies. The first and second heart sounds, caused by tissue movement, are too short in duration to be musical. Therefore heart sounds and murmurs are non- musical “noises”. Yet they are a continuum of mixed frequencies and are a form of music, albeit non-musical music, and occur in rhythms that vary. Thus, in the appreciation of heart sounds and murmurs, methods that are proven to work in music teaching should apply to teaching cardiac auscultation.

A further argument for adapting methods of music teaching for cardiac auscultation is that there is general belief that good cardiac auscultators are musical. Five percent of people are tone-deaf¹⁵. The remainder have varying degrees of musicality, with the highest having perfect pitch and rhythm. Music teachers have strong evidence that one’s musicality can be improved, with certain teachers even believing that everyone can achieve perfect pitch . Computer downloads are available which purport to increase musicality¹⁴. Suggestions of ways in which one’s musicality may be increased include: repeatedly listening to recordings; daily listening; attempts to replicate; tune in on YouTube and snap fingers or clap hands to rhythms.

Novel ideas which might bring the methods of music teaching and sound recognition to bear on heart auscultation include session(s) by music teachers in first-year medical training; assessment of students’ musicality, and follow-up after institution of programs to increase musicality; assessment of cardiac auscultation skill prior to beginning use of the stethoscope. It is recognized that the personality of the student is another factor, i.e.: the presence of a talent does not necessarily assure its use.

A health care professional is graduating and plans to solo practice in a remote area, miles from availability of cardiac ultrasound. The student does not possess the skill to differentiate normal heart sounds from abnormal. Recognizing that no health care plan is perfect, the area will suffer when this person places a stethoscope on a patient’s chest. Where does the cause of this deficiency lie? In the student? In the university? In the local medical association? In the government?

Teachers must realize that improvement in this area of health care delivery is possible and take steps to correct this deficiency.