Atrial tachycardia is the least common type of supraventricular tachycardia. It's generally seen in children with underlying heart disorders such as congenital heart disease, particularly those who've had heart surgery.
Atrial tachycardia may also be triggered by factors such as an infection or drug or alcohol use. For some people, atrial tachycardia increases during pregnancy or exercise.
Atrial tachycardia episodes typically begin slowly, gradually increasing to more than 100 beats per minute before returning to a normal heart rate of around 60 to 80 beats per minute. In some cases, these episodes occur more abruptly or occur continuously.