Hand held Ultrasound and the Stethoscope

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					                                                                           Cardiac Imaging

                                                       Hand-held Ultrasound and the Stethoscope

        a report by
        Daniel M Shindler

        Director, Echocardiography Laboratory, Robert Wood Johnson University Hospital

The stethoscope was invented in the early 19th century.         most cardiac disorders. At the same time, the scientific
It is now the most readily recognized tool of the               literature on echocardiography has validated its extensive
physician and healthcare worker, yet its demise has been        diagnostic capabilities.
wrongly but repeatedly foretold over the years. This
usually occurs when other diagnostic tools are invented         Echocardiography provides extensive anatomic and
and gain popularity. There is an old tale of an early           functional information about the heart. It often clarifies
20th-century radiologist who placed a stethoscope               stethoscopic, electrocardiographic, and X-ray findings.
prominently for all to see in a coffin-shaped display           Both the stethoscope and the ultrasound exam of the
case. It was his mistaken belief that X-ray of the heart        heart provide physical evidence of abnormalities, but          Daniel Shindler is the Director of
would shortly render the stethoscope obsolete.                  the ultrasound may be more informative at an earlier           the Echocardiography Laboratory
                                                                stage of a disease. For example, ultrasound can actually       at Robert Wood Johnson University
                                                                                                                               Hospital, where he teaches bedside
More recently, and the point of this article, a small           measure the strength of cardiac muscle in heart failure.       cardiac physical diagnosis. His
ultrasound machine is being hailed as the new                   The stethoscope will only provide such evidence late in        group pioneered wireless
stethoscope.This is bolstered by recent medical literature      the course of the disease when the heart actually begins       transmission of echocardiograms in
                                                                                                                               the late 1980s. He devotes a large
bemoaning the loss of auscultation skills by the latest         to enlarge and fail. Ultrasound can help identify which        amount of his efforts to medical
generation of doctors. Physician reliance on the                coronary artery caused a heart attack. Readily available       Internet education and is the
stethoscope has indeed decreased.A 21st-century medical         ultrasound may shorten the time it takes to make a             founder and moderator of the
                                                                                                                               largest e-mail echocardiography
student is initially exposed to cardiac auscultation with       diagnosis. It can identify causes of chest pain other than     discussion group on the Internet:
inspiring lectures that often incorporate innovative            heart attacks, altering the treatment of patients              http://health.groups.yahoo.com/group
electronic teaching techniques of heart sounds. This            dramatically and providing correct life-saving diagnosis       /echocardiography/
                                                                                                                               The echocardiography journal that
usually spurs their enthusiasm for the stethoscope. After       in many cases.                                                 he edits has been freely available
all, it is the symbol of their chosen profession.This short-                                                                   on the Internet since 1995 at:
lived enthusiasm for auscultation is evident during their       Nevertheless, it is unwise to alter the customary              http://www2.umdnj.edu/~shindler/
                                                                                                                               It has been consistently top ranked
rotations in the clinical third and fourth years, where they    sequence of evaluating a patient in most cases. After          by Google. He also writes essays
examine real patients with a stethoscope. Unfortunately,        obtaining a history from a patient, a physical examination     on cardiac auscultation at
soon afterwards, when time becomes precious during              (including auscultation) should be performed. At that          http://efslope.com
                                                                                                                               Professor Shindler received his
their internship and residency, they seem to come to the        point, the stethoscope may reveal that a calcified valve has   cardiology training at the University
inevitable conclusion that the ultrasound machine is            caused this patient to faint. Detailed ultrasound using the    of Medicine and Dentistry of
much more expeditious and accurate in establishing a            high-end equipment will still be required to decide            New Jersey – Robert Wood Johnson
                                                                                                                               Medical School, where he is now
cardiac diagnosis. Their interest in further learning the       whether to proceed with an operation to replace the            an Associate Professor.
fine points and nuances of using a stethoscope wanes.This       valve. An out-of-sequence cursory or limited ultrasound
is especially true if there is no knowledgeable mentor          examination performed during the initial evaluation may
available to teach them the fine art of honing their still-     not reveal the true extent of the problem.
immature auscultation skills.Auscultation role models are
hard to find. It becomes more practical to order an             As ultrasound technology improves, the image resolution
ultrasound study than to spend time listening to the heart.     gets progressively better, but there is still a significant
                                                                minority of patients that are difficult to image. In those
Over the last 30 years, cardiac ultrasound (usually             people it is occasionally necessary to insert an ultrasound
referred to as echocardiography) has emerged as a               probe into the esophagus to image the heart without
powerful diagnostic tool for patients with heart disease. It    obstruction from ribs or from lung tissue. It is called
has dramatically altered the diagnostic approach in             transesophageal echocardiography (TEE).This is a semi-
children with congenital heart disease. Echocardiography        invasive procedure that is fairly safe, but does carry some
has virtually replaced cardiac catheterization as the           degree of discomfort. It has revolutionized the medical
primary diagnostic tool in most of pediatric cardiology.        treatment of some heart rhythm disorders and the
In adult cardiology, echocardiography has emerged as a          surgical treatment of heart valve disorders and has
convenient and reliable first-line method of testing in         become an indispensable tool in specialized heart centres.                                     51

                              Cardiac Imaging

     There are now briefcase-sized ultrasound TEE                   untrained personnel with scaled-down equipment is not
     machines. Smaller book-sized machines can be hand-             the answer. The power of hand-held ultrasound is its
     carried to the bedside and a transducer applied to the         point-of-care availability – it can make a diagnosis
     chest in much the same way as the stethoscope. They            quickly, yet this is precisely where experience is
     are less expensive than the standard high-end                  important. One cannot afford to make the wrong
     ultrasound machines and their price is expected to             diagnosis in a critical care setting. There may not be a
     continue to drop. Ultimately, ultrasound machines may          second chance.
     shrink down even further to the size of a personal
     digital assistant (PDA) or even a cell phone. The              One approach to this dilemma is to recognize the
     ultrasound transducers may become small enough to fit          hand-held device for what it is. It is a miniature version
     in a medical coat pocket just as easily as the stethoscope.    of the larger but more capable standard high-end
     Wireless transmission of the images has long been              ultrasound machine. Recognizing the differences
     possible, further expanding portability.                       between the two is fairly easy to instill in healthcare
                                                                    providers because there is a precedent. It is well known
     Echocardiographic studies were initially recorded on           that transesophageal echocardiography may be
     videotape, but images are now increasingly being stored        necessary in some patients because the standard
     on computers and viewed in digital form. Digital storage       echocardiogram will not provide all the required
     may enable one to go from patient to patient with a            information. Similarly, the standard echocardiogram
     relatively small device to obtain, store, and electronically   may be necessary to supplement incomplete
     transmit diagnostic ultrasound information. It is therefore    information obtained by the hand-held device. Once
     not surprising that these small hand-held ultrasound           complete information is gathered by the standard high-
     machines are being hailed as the future replacement of a       end echocardiogram, it may be perfectly acceptable to
     non-electronic instrument approaching its bicentennial.        use a hand-held device for a focused, goal-oriented
                                                                    limited follow-up study. As with other aspects of the
     Echocardiographic knowledge and experience are key             practise of medicine, a qualified, properly trained
     concerns. Both scanning and interpretation require             health practitioner will need to assume responsibility
     training and experience. In the US, echocardiographic          (and will be held accountable) for how the information
     procedures are typically performed by technician               is obtained and interpreted. Proper record-keeping is
     sonographers.The level of training and the quality of the      essential. Reimbursement issues will doubtless also
     training can vary. To work as a sonographer, one usually       influence the eventual role of hand-held ultrasound in
     goes to an ultrasound school and then receives hands-on        cardiac diagnosis and treatment.
     training. Sonographers are encouraged but not required
     to take a certifying examination. Echocardiographic            Proper utilization is further refined by a plan to use the
     studies are usually interpreted by cardiologists with          hand-held device extensively for bedside teaching of
     specialized training. Cardiologists can become board-          both patients and healthcare providers. A sonographer
     certified in echocardiography. In addition, an increasing      performing a study in an echocardiography laboratory
     number of echocardiography laboratories are voluntarily        without a physician is legally prohibited from discussing
     submitting to a lengthy and rigorous accreditation process     the echocardiographic findings with the patient. As a
     that invariably improves the quality of the laboratory.        result, patients usually leave the echocardiography
                                                                    laboratory somewhat disappointed that the images of
     A resident or inexperienced physician performing an            their heart were not explained to them during the study.
     ultrasound study is highly unlikely to obtain the same         On the other hand, a properly trained and credentialled
     information as an experienced sonographer or an                physician coming to the bedside with a hand-held
     experienced specialist. In many cases, incorrect               device can use it to educate the patient as well as the rest
     information may be more harmful than no information.           of the healthcare team. Such an approach can integrate
                                                                    the visual information from the ultrasound device with
     Ready availability of hand-held ultrasound equipment           the auditory information from the stethoscope, thereby
     may help make a critical diagnosis quickly.This can be         increasing skills in both techniques.
     in an emergency room in the middle of the night, in a
     critical care unit, in an ambulance, or even on the            Many people feel that the stethoscope hanging around
     battlefield. If confined to certain disorders, hand-held       the neck of healthcare workers is already just a symbol,
     ultrasound far exceeds the capabilities of the                 and no longer provides adequate diagnostic
     stethoscope. However, proper training in the use and           information. For the near future at least, stethoscopes
     limitations of the ultrasound instrument is mandatory.         should continue to hang there, waiting to be used by
                                                                    those who know auscultation, while echocardiograms
     Many places around the world are reporting shortages of        (hand-held or standard) should be performed and
52   experienced sonographers. Unleashing inexperienced,            interpreted by those who know echocardiography. ■

                                                                                BUSINESS BRIEFING: US CARDIOLOGY 2004

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