Atrial Antitachycardia Pacing in Congenital Heart Disease: One Algorithm Does Not Fit All.

We present the case of a 24-year-old male with congenitally corrected transposition of the great arteries and recurrent slow atrial tachyarrhythmias (ATs). The patient was initially implanted with a Medtronic cardiac resynchronization therapy defibrillator (CRT-D) featuring an atrial antitachycardia pacing (aATP) algorithm, which showed suboptimal efficacy in terminating AT episodes. Replacing the device with a Biotronik CRT-D, equipped with an alternative aATP algorithm capable of treating slow ATs, resulted in successful termination of the AT episodes and significant symptom relief. This case underscores the importance of tailoring the choice of aATP algorithm to the individual needs of patients with congenital heart disease.