Successful radiofrequency ablation of adenosine-sensitive right ventricular outflow tract tachycardia

We report on a patient without evidence of structural heartdisease who presented with adenosine-sensitive sustained ventriculartachycardia with left bundle branch block and right axis QRSmorphology. Endocardial catheter mapping revealed the originof ventricular tachycardia to be located in the right ventricularoutflow tract, where the earliest endocardial activation duringventricular tachycardia was registered 30–40 ms priorto onset of QRS complex in the surface ECG. Pacemapping providedno additional information; we found a good match between 12lead surface ECGs registered during spontaneous episodes ofventricular tachycardia and those recorded during pacing ina relatively large area in the right ventricular outflow tract.The 10th application of radiofrequency current abolished ventriculartachycardia temporarily, but it recurred within 30 min. Afterthe 28th radiofrequency current delivery ventricular tachycardiawas permanently abolished.