Pediatric dysrhythmias.

Arrhythmias in children are less common than in adults but are increasing because of successful repair of congenital heart diseases. Supraventricular tachycardia is the most common symptomatic pediatric tachyarrhythmia. Atrial flutter and atrial fibrillation in children are attributed largely to structural heart disease. Bradycardia is defined as a heart rate less than the lower limit of normal for a child's age, and the most common cause is sinus bradycardia. Despite the infrequent occurrence of arrhythmias, it is crucial to expeditiously identify and treat certain rhythm abnormalities because they can lead to further decompensation.