PEDIATRIC COLUMN

Pediatric and Congenital Heart Disease Council CommunicationImproving the Chances of Being Right

In dealing with patients with congenital heart disease, there are manyways to be wrong. One common error is to miss the correct diagnosis,which can lead to other potential errors, such as sending a patient tocatheterization or surgery too early, too late, or even for the wrongprocedure. In addition to the missed (false negative) diagnosis, onehas the capability to make an incorrect or false positive diagnosis. Di-agnostic errors can lead to additional tests, which carry their own risks.

The correct diagnosis can be easily missed if the echocardiographicimaging windows are suboptimal, as is common during an echocar-diogram on a fetus or very large adult. Even on a small child, the imagequality can be suboptimal if the child is unable to cooperate with theexamination. With the advent of better two-dimensional imagingtechnology, color Doppler, and transesophageal probes, our imagesare much better than before. Sedation of a young child can lead tobetter study information. Frequently, it is the completeness of thestudy and the skills of the operator and reader that determine the di-agnostic accuracy of the echocardiogram rather than the quality of theimages.

An example of an easily missed diagnosis is the patent ductus arte-riosus in the setting of severe pulmonary hypertension. Flow in theductus is right-to-left and can be difficult to visualize; there is minimalor no diastolic left-to-right shunting. Some of these patients needurgent surgery; for others, the opportunity for a simple repair haspassed due to a delay in diagnosis. The consequences of a falsepositive diagnosis are usually less dire. A common scenario is thepatient referred for a second opinion for a suspected anomalous cor-onary artery origin, either from the contralateral sinus of valsalva orfrom the pulmonary artery. These patients may have been referredas potential candidates for cardiac magnetic resonance imaging, CTscan, or cardiac catheterization. Not uncommonly, the diagnosis ofa normal coronary artery origin or normal coronary variant—for ex-ample, a high takeoff of the coronary artery just above the level ofthe sinotubular junction but not from the contralateral sinus—was ap-parent on the outside echocardiogram, or could be seen on a repeatechocardiogram. The false positive diagnosis, although temporary,has often resulted in significant anxiety for the patient and family,and in unnecessary restriction from activities. These types of diagnos-tic errors happen in clinical centers around the country.

The ASE has sought to address the issue of diagnostic errors withthe publication of guidelines and standards for fetal, pediatric, andcongenital transesophageal echocardiograms, which are readily avail-able on the ASE Website, www.asecho.org. Moreover, the ASE hasendorsed a task force document on ‘‘Pediatric Training Guidelinesfor Noninvasive Cardiac Imaging’’.1 Based on this document, theASE Guidelines and Standards for Performance of a Pediatric Echo-cardiogram further outlined the requisite knowledge for the coreand advanced levels of expertise, delineated the required skills, andsummarized the training methods recommended for the two levelsof expertise.

ASE is also a strong supporter of laboratory accreditation throughthe Intersocietal Commission for the Accreditation of Echocardiogra-phy Laboratories (ICAEL). Laboratory accreditation, while a time-consuming process, is a means of raising the standards of studiesacross the country. In addition to recognizing laboratories that providequality echocardiographic services, the accreditation process is also

meant to improve theoverall quality of the labo-ratory through emphasison training, continuingmedical education, andquality assurance.

More recently, our at-tention has turned to-wards the difficult task ofmaking clinical decisionsbased on ‘‘borderline,’’ orequivocal, diagnoses inyoung and growing chil-dren. In these situations,one is often faced withthe uncertainty of know-ing whether a structure isnormal in size, too big,or too small. For example,how does one determineif left ventricular parameters are adequate for a biventricular outcomein an infant with left-sided obstruction? When does the aortic root ofa teenager with Marfan syndrome require surgery? How does one fol-low the left ventricular size of a child with aortic regurgitation? In ad-dition to the pathology present, the measurements of vessel andchamber size are confounded by body size, age, and overall somaticgrowth.

In the next year, the ASE will be coming out with guidelines onquantification methods during a pediatric echocardiogram. It will bea consensus document of what and how measurements should bemade, but it is only the first step. Following its release, our communityof imagers will be challenged to find funding for the creation of a nor-mative database that reflects the general population of children of allsizes. Ideally, the database would be large enough to allow for testingthe effects of potential confounders such as sex and race. This will re-quire a multi-center collaboration and one or more echocardiographycore labs. Once in place, this infrastructure should allow for the morerapid incorporation of new technologies into practice by providinga network to collect normal data for newer techniques such asthree-dimensional or strain imaging.

In summary, the strategies now in place for decreasing diagnostic er-rors include the creation and dissemination of guidelines, emphasis ontraining, echocardiography laboratory accreditation, and quality assur-ance. With these, and the development of a robust, population-basednormative database for children, it should be easier for all of us to beright more often than not, even on the most difficult of cases.

REFERENCE

1. Sanders SP, Colan SD, Cordes TM, Donofrio MT, Ensing GJ, Geva T, et al.ACCF/AHA/AAP recommendations for training in pediatric cardiology.Task force 2: pediatric training guidelines for noninvasive cardiac imagingendorsed by the American Society of Echocardiography and the Societyof Pediatric Echocardiography. J Am Coll Cardiol 2005;46:1384-8.

Wyman W. Lai, MD, MPH, FASE

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