Author + information
- Lars Grosse-Wortmann, MD∗ ( and )
- Robert Hamilton, MD
- ↵∗The Labatt Family Heart Centre, The Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada M5G 1X8
We thank Dr. te Riele and colleagues for their interest in our paper. We value the input and expertise of the authors, who represent a large combined experience, and whom we often seek out for research review and clinical opinions related to patient management. We share the authors’ concern regarding the applicability of the revised Task Force Criteria to a pediatric population, as emphasized in our article. Nonetheless, and despite its recognized shortcomings, the revised Task Force Criteria continue to be widely used during evaluation for arrhythmogenic right ventricular dysplasia (ARVC) in pediatric patients. Groeneweg et al., in a paper that included many of the authors of the current letter regarding our paper and to which te Riele et al. refer, reported 4 (1.0%) of 416 index patients presenting at <13 years of age (1). It is important to consider that one can only diagnose patients who are referred, and that referral may incorporate a significant bias. Most programs within adult cardiovascular units are rarely referred pediatric probands. The age range for patients in our cohort was 3 to 18 years of age at the time of magnetic resonance imaging. Five patients in the “borderline” (15.6%) and 2 in the “definite” category (8.7%) were <13 years of age. Several reports have suggested that the prevalence of ARVC in pre-pubertal children is not negligible and that it is, in fact, an important cause of sudden cardiac death (SCD) in the young. Tabib et al. (2), in a series of 200 cases, found that as many as 10% of SCDs associated with ARVC occurred in individuals younger than 18 years of age, including several before 10 years of age. The same group (3) identified that ARVC caused essentially the same number of SCDs in children age 8 to 18 years of age as hypertrophic cardiomyopathy, including a 7-year-old and two 12-year-olds. More recently, Pilmer et al. (4) reviewed all SCDs in Ontario (population 13.6 million) in 1- to 19-year-olds during a 5-year period and found that 25% of SCD victims had ARVC or possible ARVC, equaling or exceeding any other cause.
We have experienced several cases that highlight the importance of making the diagnosis during childhood, including a 10-year-old boy with clinical ARVC who died participating in sport against medical advice and refusing an implantable cardioverter-defibrillator, and two 10-year-old female victims of SCD with clear pathology of ARVC, as demonstrated by the classical sign of transillumination shown in one of them (Figure 1). In te Riele et al.’s own experience, there is at least 1 patient <13 years of age who presented with a life-threatening arrhythmia (1). Such deaths will never be preventable if we do not unveil the occurrence and significance of this condition in children and adolescents. The small contribution of echocardiography to the performance of the revised Task Force Criteria in this population did not surprise us, given the limitations of ultrasound in visualizing the most anterior portions of the heart in combination with often subtle wall motion abnormalities that are in young individuals.
We thank the authors for pointing out that repolarization abnormalities are not applicable before 14 years of age. Ultimately, age-specific norms for T-wave amplitude are anticipated to be useful, although this is a more complex measurement and not part of the revised Task Force Criteria that were applied in our study. Dr. te Riele and colleagues relate their observation that Holter abnormalities typically precede structural findings on imaging. In our clinical practice, and borne out by the data from our study, pediatric patients rarely fulfill the major criterion for arrhythmias. Arrhythmias as a minor criterion were more prevalent but did not distinguish between the different diagnostic certainty groups.
Dr. te Riele and colleagues highlight that at the time of data collection, only 49 of 142 patients had undergone genetic testing. Despite the undisputed value of genetic testing both within and outside of the Task Force Criteria, important limitations of genetic testing must be recognized: up to 50% of ARVC patients are gene-elusive, and 30% to 40% of gene-positive patients remain nonpenetrant well into adulthood (5). Thus, at present, the presence of an ARVC mutation cannot provide an alternate standard for the presence of ARVC disease.
Once again, we would like to thank Dr. te Riele and colleagues for their critical review of our work and for highlighting important areas for future research. In a disease that contributes significantly to pediatric and young adult sudden death, and which, once established in the adult, is likely difficult to reverse, improvements in pediatric diagnosis will be paramount.
Please note: The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- 2015 American College of Cardiology Foundation
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