RADIOFREQUENCY CATHETER ABLATION OF AN INCESSANT SUPRAVENTRICULAR TACHYCARDIA INITIATED BY A HISIAN PARASYSTOLE

The coexistence of a parasystolic focus, tachycardia dependent right b undle branch aberrancy, and an AV accessory pathway is reported here. This condition was present in a 40-year-old man, which led to an inces sant AV reciprocating tachycardia. Further electrophysiological study revealed that the parasystolic focus was located somewhere in the His bundle; endocardial mapping disclosed a right posterior accessory path way. Radiofrequency current was delivered at the atrial level of the r ight posterolateral AV groove and successfully ablated the accessory p athway, leading to a dramatic improvement in cardiac function. In conc lusion, the recognition of the electrophysiological mechanism of inces sant supraventricular tachycardia was of crucial importance for the th erapy decision. A definitive intervention using radiofrequency cathete r ablation should be considered early and not postponed in patients wi th tachycardia-induced cardiomyopathy.