An argument for reviving the disappearing skill of cardiac auscultation
SCENARIO 3: NORMAL HEART VALVES?
A 62-year-old woman presented to her local cardiologist with a 3-month history of worsening shortness of breath and fatigue. She had an abnormal nuclear stress test that led to left heart catheterization, which revealed a 60% to 70% stenosis of the left main coronary artery. She was promptly referred for coronary artery bypass grafting.
The report from her referring cardiologist indicated normal findings on her cardiac physical examination. However, when we examined her, we noted an accentuation of the first heart sound, with an opening snap and a low-pitched mid-diastolic rumble heard best at the apex, in addition to a systolic ejection murmur, diminished second heart sound, and late-peaking carotid upstroke. Echocardiography revealed significant mitral stenosis, with a mitral valve area of 1.05 cm2, as well as moderately severe aortic stenosis. These findings were consistent with rheumatic heart disease, and upon questioning, the patient reported that she had received that diagnosis in her 30s while teaching in China.
In light of the findings on physical examination and imaging, the patient underwent mitral and aortic valve replacement in addition to the coronary bypass procedure for which she had originally been referred.
A SELF-FULFILLING PROPHECY
These vignettes illustrate the importance of a detailed physical examination—particularly cardiac auscultation—in the clinical evaluation of structural heart disease.
In the first two, there were significant inconsistencies between the auscultatory and echocardiographic findings, and information obtained from careful cardiac auscultation ultimately directed further testing and led to the correct diagnosis. The third scenario is particularly worrisome in our opinion, as it not only represents a lack of auscultatory skills, but probably a failure to listen at all. Further, in this patient’s case, failure to diagnose significant valvular disease would likely have meant a need for reoperation at a later date.
Although this is clearly unacceptable, in our experience it is not uncommon. As the skill of auscultation is lost, less and less information is obtained, and the abandonment of auscultation becomes a self-fulfilling prophecy.
AUSCULTATION SAVES MONEY
While these cases show the diagnostic capability of cardiac auscultation, they also show that auscultation has another virtue: it can save money. With skyrocketing health care costs, cost-effectiveness of care is increasingly important. In fact, the modern physician is called to the commitment of the just distribution of finite resources as a principle of medical professionalism.5 Physicians skilled in cardiac auscultation will be better able to distinguish patients who do not have significant disease and, therefore, will provide more appropriate care by decreasing the mindless use of expensive imaging.
Physicians, especially cardiologists, who are not worried about the loss of auscultatory skills are likely those who do not know how to properly auscultate the heart and, therefore, do not appreciate the vital information it may provide. Dependent on echocardiography, they fail to recognize its numerous limitations, particularly in a real-world setting where core echocardiography laboratories are not commonplace. Furthermore, the use of sophisticated hand-held echocardiography machines, often by inexperienced and untrained operators, is on the rise.
Echocardiography: Still an imperfect science
Many variables contribute to the echocardiographic assessment of severity in valvular heart disease. These include jet size and character, which may be affected by inappropriate gain settings, Nyquist limits, wall filters, ultrasound beam angulations, and regurgitant orifice area calculations. Other factors potentially affecting echocardiographic reproducibility include variability between machines, sonographers, and interpreters, as well as differences in medications, loading conditions, and blood pressure.6,7 This potential for variability in echocardiography underlines the importance of auscultation, particularly at tertiary referral centers, where many patients are evaluated and treated on the basis of testing at other facilities. Although echocardiography has rightfully become the cornerstone of diagnosing valvular heart disease, we may often forget that it is an imperfect science.
Well-honed cardiac auscultatory skills are still an essential part of medical practice and are an indispensable complement to echocardiography. For this reason, medical schools and training programs in cardiology should encourage a renaissance in the art of cardiac auscultation and bedside clinical diagnosis, which we believe will ultimately improve patient care. Excellent resources are available for teaching auscultation, including Web sites and audiovisual software. And there may even be a wise old doctor still around for advice.
Acknowledgment: We would like to thank Jane Owenby for her assistance in the preparation of this manuscript.
