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Induction of nonsustained atrial flutter by programmed atrial stimulation in children: incidence, mechanisms, and
Insights
Programmed atrial extrastimulation can induce nonsustained atrial flutter in children with congenital heart defects, even without prior arrhythmia evidence. Atrial refractoriness, not P wave duration, determines flutter cycle length in these cases.
Area of Science:
- Pediatric Cardiology
- Electrophysiology
- Congenital Heart Disease
Background:
- Congenital heart defects (CHDs) can predispose children to arrhythmias.
- Electrophysiologic evaluation is crucial for assessing arrhythmia risk in these patients.
- Nonsustained atrial flutter is a transient arrhythmia that may occur in specific contexts.
Purpose of the Study:
- To investigate the induction of nonsustained atrial flutter in children with CHDs using programmed atrial extrastimulation.
- To determine the electrophysiologic characteristics and determinants of induced atrial flutter in this pediatric population.
- To identify factors that may predispose children to developing atrial flutter during electrophysiologic studies.
Main Methods:
- Electrophysiologic evaluation including programmed atrial extrastimulation was performed in 137 children with preoperative CHDs.
- Induction of atrial flutter was assessed, and its cycle length, duration, and relationship to atrial refractory periods were analyzed.
- Patients' baseline electrocardiogram (ECG) and clinical data were reviewed for evidence of pre-existing arrhythmias.
Main Results:
- Nonsustained atrial flutter was induced in 6% (4%) of the 137 children studied.
- None of the affected children had prior ECG or clinical evidence of arrhythmias.
- Induced flutter cycle length correlated with atrial refractory periods, and prolonged PA interval or P wave duration were not observed as predisposing factors.
Conclusions:
- Programmed atrial extrastimulation can induce nonsustained atrial flutter in children with CHDs who are otherwise free of arrhythmias.
- Atrial refractoriness appears to be the primary determinant of flutter cycle length in these pediatric cases.
- Unlike in adults with clinical atrial flutter, prolonged atrial conduction times (PA and P wave duration) are not identified as risk factors in this pediatric cohort.
Abstract:
Nonsustained atrial flutter was induced by programmed atrial extrastimulation in 6 (4%) of 137 children with preoperative congenital heart defects, who underwent electrophysiologic evaluation as part of cardiac catheterization. None of these patients had ECG or clinical evidence of arrhythmias. Atrial reentry was induced by programmed atrial extrastimulation in these six patients at coupling intervals slightly longer than the coupling interval at which flutter was induced. The flutter cycle length was similar to the atrial refractory periods. The duration ranged between 0.4 second and 60 seconds. The PA interval and the duration of the P wave were normal in all of the patients. Five of the six had normal PR intervals. It is concluded that nonsustained atrial flutter may be induced by programmed atrial extrastimulation in dysrhythmia-free children. The cycle length is determined by atrial refractoriness and, contrary to adults with clinical atrial flutter, prolonged PA and P wave duration are not predisposing factors.