Impact of the T-wave characteristics on distinguishing arrhythmogenic right ventricular cardiomyopathy from healthy children

Highlights

• This study clarified the frequency of T-wave inversion (TWI) in a large cohort of healthy children.

• T-wave discontinuity (TWD), as well as TWI in the inferior and anterior leads could differentiate ARVC children.

• TWD and anterior TWI are possible signs to predict a serious prognosis in the future.

• ARVC children tend not to have VTs but have PVCs and late potentials.

Abstract

Background

T-wave inversion (TWI) is not considered useful for diagnosing pediatric arrhythmogenic right ventricular cardiomyopathy (ARVC), because right precordial TWI in ARVC resembles a normal juvenile pattern.

Objectives

The aims of this study were to clarify the electrocardiographic (ECG) characteristics of pediatric ARVC to distinguish those patients from healthy children.

Methods

Between 1979 and 2017, 11 ARVC patients under 18 years old were registered and compared with school screening ECGs from 48,401 healthy children.

Results

The mean age at the first arrhythmic event or diagnosis was 13.3 ± 4.7 years. Nine patients were asymptomatic initially and were found by ECG screening, but 6 developed severe symptoms during the follow-up. Healthy children had a normal juvenile pattern, while ARVC children, especially symptomatic patients, had a significant tendency to have inferior and anterior TWI. The phenomenon of T-wave discontinuity (TWD) in which the TWI became deeper from V1 to V3 and suddenly turned positive in V5 was significantly more frequent in ARVC (60%) than healthy children (0.55%). Anterior TWI and TWD were also significantly more frequent in those who developed severe symptoms. The sensitivity and specificity of TWD were 60% (95% CI, 31–83%), and 99% (95% CI, 99–99%) to distinguish ARVC from healthy children, as well as 100% (95% CI, 71–100%) and 80% (95% CI, 51–80%), respectively, to predict severe symptoms in the future.

Conclusions

The ECG is useful to distinguish ARVC children, even in the early phase. Anterior TWI and TWD could detect ARVC children and to predict the possible serious conditions.

Introduction

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a rare inherited progressive myocardial disease characterized by fibro-fatty replacement in the right ventricle (RV). ARVC typically becomes manifest with ventricular arrhythmias during the patients' twenties to forties, sometimes causing sudden death [1,2]. Pediatric cases are rare due to age-related penetrance, but those patients are reported to have a higher risk of life-threating arrhythmias than adult patients [3].

The diagnosis of ARVC is generally made by the revised Task Force Criteria (rTFC), including 12‑lead electrocardiograms (ECGs), Holter ECGs, signal-averaged ECGs (SAECGs), echocardiography, cardiac magnetic resonance imaging (CMR), angiography, and a detailed family history [4]. However, most of those findings may become manifest after an advanced state of the disease [5,6], therefore pediatric asymptomatic patients have the risk of being overlooked.

Because the ECG is one of the easiest, non-invasive, and low-cost examinations, it is important for screening for ARVC [7]. Although T-wave inversion (TWI) in right precordial leads is adopted in the rTFC, it is generally recognized as a normal juvenile pattern in children, therefore, this finding sometimes confuses the diagnosis of pediatric ARVC patients. To prevent this confusion, the rTFC does not include TWI in children less than 14 years old, but ARVC children with fewer findings other than TWI may be overlooked. Prior studies have focused on the prevalence of TWI between ARVC patients and healthy adults [[8], [9], [10]] or young athletes [11,12], but there have been no reports comparing the TWI characteristics between ARVC children and healthy children.

In Japan, for the purpose of an early detection of heart diseases, school heart screening is established as a national system, and is performed annually for students in the 1st grade in elementary school (6 years old), 7th grade in junior high school (12 years old), and 10th grade in high school (15 years old). It consists of simple, convenient, and cost-effective examinations such as questionnaires, physician's assessments, and ECGs. The current ECG criteria for the Japanese primary screening have been described in a previous paper [13], and 1) TWI ≥ 0.1 mV in leads I, II, aVL, aVF, or V3 to V6, 2) a notch (ε-wave) after the QRS waves in leads V1–V3, and 3) the presence of left bundle branch block (LBBB) type ventricular tachycardias (VTs) or premature ventricular contractions (PVCs), have been applied for ARVC [13]. However pediatric ARVC patients rarely exhibit characteristic findings such as ε-waves or VTs [14], hence, there would be a great advantage if we could suspect the presence of ARVC with a TWI pattern during the primary screening.

The present study aimed to clarify the difference of TWI characteristics between ARVC and healthy children, and to predict the severity on the basis of the ECG.