Utility of incomplete right bundle branch block as an isolated ECG finding in children undergoing initial cardiac
Omar Meziab1, Dominic J Abrams1, Mark E Alexander1
1Boston Children's Hospital, Boston, Massachusetts, USA.
Insights
Incomplete right bundle branch block (IRBBB) is common in healthy children but shows high variability among pediatric electrophysiologists. This ECG finding increased echocardiogram use without detecting more cardiac issues.
Area of Science:
- Pediatric Cardiology
- Electrophysiology
- Diagnostic Imaging
Background:
- Incomplete right bundle branch block (IRBBB) is an electrocardiogram (ECG) finding.
- Its clinical significance and diagnostic reliability in children are not well-established.
- This study investigates IRBBB in healthy pediatric outpatients.
Purpose of the Study:
- To evaluate the reliability of pediatric electrophysiologists in classifying IRBBB.
- To assess the clinical utility of isolated IRBBB as an ECG finding in children.
- To determine the association of IRBBB with echocardiographic findings.
Main Methods:
- Retrospective analysis of ECG and echocardiogram records from Boston Children's Hospital (2005-2014).
- A subset of 473 ECGs was reanalyzed by six pediatric electrophysiologists in a blinded manner.
- Inter-reader variability for IRBBB classification was assessed.
Main Results:
- Of 32,127 analyzed ECGs, 3.0% were coded as IRBBB.
- Inter-reader variability for IRBBB identification was high, ranging from 1% to 20%.
- IRBBB was associated with increased echocardiogram use (12.5% vs 7.3% for normal ECGs) but not with more cardiac findings.
Conclusions:
- IRBBB is a common ECG finding in healthy school-aged children.
- High inter-reader variability exists in diagnosing IRBBB.
- Isolated IRBBB does not appear to be a significant indicator of underlying cardiac pathology in this population.
Objective:
This study evaluates the ability of experienced pediatric electrophysiologists (EPs) to reliably classify incomplete right bundle branch block (IRBBB) and assesses its clinical utility as an isolated ECG finding in a group of healthy outpatient children without prior cardiac evaluation.
Design:
We performed a retrospective analysis of all electrocardiographic and echocardiographic records at Boston Children's Hospital between January 1, 2005, and December 31, 2014. Echocardiographic diagnoses were identified if registered between the date of the index electrocardiogram and the ensuing year. A selected subset of 473 ECGs was subsequently reanalyzed in a blinded manner by six pediatric EPs to determine the consistency with which the finding of IRBBB could be assigned.
Results:
Of the 331 278 ECGs registered in the BCH database, 32 127 (9.7%) met inclusion criteria and were analyzed for the prevalence of isolated right bundle conduction disturbance findings. The mean age was 12.1 ± 4.0 years, and the population was 49% male. Of the 32 127 ECGs, 72.5% were coded normal, 3.0% were coded IRBBB, and 0.5% were coded complete right bundle branch block (CRBBB). A total of 7.3% of patients coded as normal had an ensuing echocardiogram, compared to 12.5% coded IRBBB. Echo findings were recorded in 0.1% of normal and 0.2% of IRBBB. Patients with ASD-secundum type were no more likely to have isolated IRBBB on previous ECG than the general population (2.5% vs 3.0%). Analysis of inter-reader variability in ECG findings and conduction disturbance identification was high (range of IRBBB prevalence 1-20% among readers). Reinterpretation of ECGs using explicit diagnostic criteria did not demonstrate consistent discrimination of IRBBB and Normal ECGs.
Conclusions:
IRBBB is not uncommon in a healthy school age population and is observed to have high inter-reader variability. It was associated with increased use of echocardiographic exam but was not associated with increased rate of echocardiographic findings when compared with rates for normal ECGs.
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