Experience with an ambulatory 12-lead Holter recording system for evaluation of pediatric dysrhythmias.
BACKGROUND
The 12-lead electrocardiogram demonstrates noninvasively many details concerning cardiac arrhythmias and their mechanism, but only for a limited period. A Holter system can record heart rhythm for a longer period, but shows 2 or 3 leads only. An ambulatory 12-lead Holter recording system combines the advantages of both. We report on our experience with the 12-lead Holter system in children.


METHODS
Twenty-four patients (age range, 3-22 years) underwent one or more 12-lead Holter recordings. Twelve patients had suspected or documented tachyarrhythmia, and 12 patients had suspected or proven long QT syndrome (LQTS).


RESULTS
In the tachyarrhythmia group, 4 patients had supraventricular tachycardia and 7 ventricular tachycardia (VT). In the supraventricular tachycardia, group 1 patient had intra-atrial reentrant tachycardia with a single reentrant circuit, whereas another had multiple P-wave morphologies, suggesting multiple circuits. Two others had evidence for concealed atrioventricular accessory pathways. One patient had isolated supraventricular ectopy. In the VT group, 4 patients had uniform VT, and 3 patients had polymorphic VT. One patient with LQTS had macroscopic T-wave alternans. Two others showed intermittent extreme QT prolongation and T-wave notching during 12-lead Holter recording.


CONCLUSIONS
Patients with uniform VT underwent catheter ablation, guided in 2 instances by intracardiac pace mapping and comparison with the 12-lead Holter QRS morphology. All reentrant supraventricular arrhythmias with single P-wave morphology were ablated. One patient with intra-atrial reentrant tachycardia and multiple circuits received an antitachycardia pacemaker. In the LQTS group, the neonate with T-wave alternans received mexiletine in addition to beta-blocker therapy.


CONCLUSIONS
In individual patients, the 12-lead Holter system provides important additional information about the arrhythmia and helps to plan appropriate therapy. Intermittent T-wave morphology changes can be diagnosed using 12-lead Holter recordings in patients with LQTS, allowing dynamic T-wave changes to be monitored. In specific cases, this may help identify patients with LQTS and also influence pharmacological therapy.
Department of Pediatric Cardiology, University of Cologne, 50937 Cologne, Germany.
M
M
Emmel
N
N
Sreeram
S
S
Schickendantz
Konrad
K
Brockmeier
D000293:Adolescent; D000328:Adult; D001145:Arrhythmias, Cardiac / Q000175:diagnosis*; D002648:Child; D002675:Child, Preschool; D015716:Electrocardiography, Ambulatory / Q000295:instrumentation*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male