Catheter ablation of ventricular tachycardias due to forward and reverse propagation across a reentrant circuit inside a nonischemic biventricular aneurysm.

A 64-year-old recipient of implantable cardioverter defibrillator presenting with a 4.7 × 3.3 cm nonischemic, biventricular aneurysm developed multiple electrical storms due to ventricular tachycardia (VT) with 2 distinct QRS morphologies. Endocardial electroanatomical mapping revealed the presence of a low-voltage area corresponding to the aneurysm, where multiple delayed potentials were recorded. Activation mapping and entrainment pacing of both VT revealed the, respectively, forward and reverse propagation of the wavefront across a single reentrant circuit inside the ventricular aneurysm. Delivery of 3 applications of radiofrequency energy to a critical segment of the reentrant pathway eliminated both VT and the electrical storms.