A 56-year-old man with non-ischemic cardiomyopathy with three prior ablations targeting two different MMVTs presented with recurrent VT. Therefore, he underwent epicardial mapping with adjuvant CT imaging which demonstrated midmyocardial scar. Fractionated potentials noted during mapping in this region, and entrainment suggested inner loop. Interestingly, pacing showed two different QRS morphologies identical to his previously ablated VTs with a long stim-QRS at this region. Epicardial ablation carried on during the VT successfully terminated it, but the VT remained inducible and required endocardial ablation to make it noninducible. The patient has been VT-free for 12 months following this ablation off antiarrhythmic drugs.

Lamin Cardiomyopathy (LC) is associated with refractory ventricular arrhythmias. Catheter ablation success rate is low due to presence of multiple circuits and intramural substrate. We present a LC case presented with electrical storm. During catheter ablation, arrhythmia was easily inducible but activation mapping, including full epicardial and endocardial mapping, failed to demonstrate the full tachycardia cycle length (70% only) suggesting intramural activation. Critical isthmus was not identified even with successful concealed entrainment on both Endo/epicardial surfaces. This case shows that even combined endocardial and epicardial catheter approach can be ineffective in identifying the full arrhythmogenic substrate in LC.