Successful radiofrequency catheter ablation of a chaotic atrial tachycardia

Chaotic atrial tachycardia is defined as a narrow QRS tachycardia with grea ter than or equal to 3 recognizable P waves in the electrocardiogram withou t one single dominant P wave and with variable P-P intervals. We report a c ase in which the chaotic atrial tachycardia was changed to a constant rate atrial tachycardia with a single P morphology after beta blocker infusion d uring the electrophysiologic study. Radiofrequency catheter ablation at a s ingle site cured this arrhythmia. We speculate that the underlying mechanis m could be due to hyper-excitability of a single focus with multiple exit r outes.