Narrow QRS complex tachycardia with fluctuation in the morphology.

A 69-year-old man without any structural heart disease underwent an electrophysiological study and catheter ablation of a paroxysmal narrow QRS complex tachycardia. He underwent pulmonary vein isolation of paroxysmal atrial fibrillation 3 years prior. No recurrent AF has been observed, however, he experienced palpitations due to a regular tachycardia. This article is protected by copyright. All rights reserved.