Elsevier

Heart Rhythm

Volume 11, Issue 12, December 2014, Pages 2322-2327
Heart Rhythm

Viewpoint: Counterpoint
Routine ECG screening in infancy and early childhood should not be performed

https://doi.org/10.1016/j.hrthm.2014.09.046Get rights and content

For all of us working in the field of inherited heart conditions, our ultimate aim is the prevention of sudden cardiac death in young people in our communities. We share the passion and drive to this aim with our colleagues Saul et al,1 who write to advocate infant screening of infants for LQTS.

Although Saul et al aimed to write an unbiased review of the subject, they present data that support screening while underrepresenting evidence against it. Their illustrative Figure 1 is arguably misleading, presenting a graph of freedom from any cardiac event in symptomatic individuals with familial LQTS. We know that 87% of deaths from LQTS occur in those who were previously symptomatic.2 This discussion, however, is not about symptomatic patients with LQTS; it is about the detection of presymptomatic individuals on a community level.

Our aim is to present evidence that has led us to oppose the conclusions and suggestions of their article. Most pediatric cardiologists do not wish to see ECG screening in infancy,3 and we are among them.

Saul et al state that there is sufficient evidence to propose ECG screening in infancy for LQTS. We disagree.

We disagree with this view for a number of reasons:(1) The effectiveness of such a program has not been evaluated in terms of outcome.(2)The ECG is an unreliable diagnostic tool with unacceptable reproducibility, specificity, and sensitivity (3)The adverse effects of overdiagnosing or underdiagnosing LQTS in thousands of individuals have not been evaluated. (4)There are no definitive criterion standard by which LQTS can be excluded once the possibility is raised, and in particular genetic testing is not sensitive or specific enough to do so. (5)There is a paucity of normative ECG and genetic data for non-Whites.

We propose what we believe is a more attractive alternative: the detection of LQTS in the community through an active multidisciplinary program to detect probands and screen family members, based around a clinical registry. This has already proven to be effective.4, 5, 6, 7, 8 If adequately resourced, this method will provide a quicker, more reliable, and more societally acceptable method to detect and manage families at risk, such that it might conceivably render population screening redundant.

Section snippets

Evaluation of outcome of neonatal ECG screening

Population-based ECG screening programs have established the likely prevalence of LQTS in Italian and Japanese children at around 1 in 2000.9, 10, 11 However, as Saul et al admit, no studies of clinical utility of such a program have been carried out. We do not know whether such a program will save lives or not, nor what the adverse consequences will be. These facts alone indicate that further research is required before mandatory mass ECG screening should be allowed to become health policy.

The ECG is an unreliable diagnostic tool with unacceptable reproducibility, specificity, and sensitivity

Saul et al propose to reevaluate every infant found with a corrected QT (QTc) interval of greater than 0.45 seconds at 3–4 weeks of life. Given that an average QTc interval for gene carriers with LQTS is 0.454 seconds,27 almost half of the individuals may not be detected. Clearly, at least one-third of the long QT gene carriers will be missed by this cutoff. One can only guess what the future medicolegal consequences of missing so many gene carriers will be, particularly in the United States.

Unintended costs and adverse effects of population screening

There have been no studies to evaluate unintended costs or potential adverse effects of population ECG screening, including of athletes.33 These costs may, for example, be financial, related to repeated investigations of the individual and family, employment issues, and unnecessary treatments, or psychosocial, from being given a wrong or uncertain diagnosis.

Mass screening and mass uncertainty

Saul et al admit that there may be unknown “minor adverse effects of population-based ECG screening.” One outcome is uncertainty for a

Excluding LQTS in borderline cases: The questionable application of genetic testing

An essential feature of any screening program is the ability to finally diagnose or exclude the condition in 100% of cases identified. Newborn oximetry is the most recent example, where an echocardiogram diagnoses or excludes congenital heart disease.35

It is very hard to “undo” a wrong diagnosis of LQTS.36 Saul et al suggest genetic testing as a means to reclassify false-positive patients, that is, lack of a known mutation implying that LQTS is not present. Given that at least 20%–30% of those

Paucity of data for non-Whites

Ethnic diversity is reflected in the ECG and in the genes. ECGs in Italian infants and in Japanese children may be different from those in other ethic groups. Different races have different repolarization patterns.39, 40 We do not know whether, on a population basis, infants from different races will have longer or shorter QT intervals.

With regard to genetics, it is increasingly evident that a pathogenicity of genetic variants varies with ancestry. For example, R1193Q in SCN5A causes Brugada

The better alternative: Detection of inherited heart diseases in the community through an active multidisciplinary program to detect probands and screen family members, based around a clinical registry

The many inherited heart conditions that are known to cause sudden death in young people are being detected in thousands internationally as multidisciplinary cardiac genetic services develop around the world.8, 46, 47, 48, 49, 50, 51

In parts of New Zealand, 1 in 4500 of the community at large have already been identified with LQTS.4 This particular service is poorly funded, with only one part-time coordinator in a country of 4.3 million over a geographic area the size of the United Kingdom.

Conclusion

There remain far too many unknowns around neonatal ECG screening for LQTS, and it fails to meet the accepted criteria for population screening for disorders.61 Mandatory screening has the potential to cause significant harm and to waste public health resources, and it requires much more research before implementation should be considered.

Instead, we recommend that health funding agencies devote efforts toward cardiac genetic services in general. They should raise public and medical awareness of

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  • Cited by (22)

    • The natural history of fetal long QT syndrome

      2016, Journal of Electrocardiology
      Citation Excerpt :

      Fifth, anticipatory postnatal care from a prenatal diagnosis improves outcome has been shown to improve outcome [25]. Lastly, screening every newborn with a 12 lead ECG is controversial, and will not detect all cases of LQTS [26]. Once suspected, the diagnosis of fetal LQTS can be confirmed by fMCG in two ways.

    • Genetic purgatory and the cardiac channelopathies: Exposing the variants of uncertain/unknown significance issue

      2015, Heart Rhythm
      Citation Excerpt :

      Then, amidst the calls for universal infant ECG screening for the early detection of LQTS,34 calls for universal genetic screening of the LQTS genes have surfaced. Although the former is clearly debatable,35 the latter has failed totally to respect the issue of background genetic noise. If 1 in 2000 whites have LQTS, and we accept the high-end contribution of 10% for SCN5A-mediated LQTS (LQT3), then accordingly, this implies that approximately 1 in 20,000 whites have LQT3.

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    Dr Skinner receives salary support from Cure Kids.

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