What is the most common cause of nonsinus tachycardia in children?

The most common cause of nonsinus tachycardia in children is accessory pathway supraventricular tachycardia (SVT). This type of tachycardia occurs when there is an extra electrical pathway in the heart, which can lead to episodes of rapid heart rate that are not due to normal sinus rhythm. Accessory pathways can facilitate rapid conduction of electrical impulses, resulting in the heart beating faster than usual.

Nonsinus tachycardia means that the heart rhythm is not originating from the usual sinus node in the right atrium, and accessory pathway SVT is particularly prevalent in the pediatric population. Because of the structural and functional characteristics of a child's heart, conditions like accessory pathway SVT can arise more frequently, especially in younger patients.

Other types of tachycardia may occur, but they are less common in children compared to accessory pathway SVT. Sinus tachycardia, while a faster heartbeat, typically reflects a physiological response to factors such as fever or anxiety and is not classified as nonsinus. Atrial fibrillation and ventricular tachycardia are much rarer in children and more often associated with underlying heart disease. Thus, accessory pathway SVT is recognized as the predominant cause of nonsinus tach