Abstract: AIM:To investigate the efficacy of linear ablation in the left ventricular (LV) septum in patients with idiopathic left ventricular tachycardia (ILVT) who were not amenable to “traditional” mapping. METHODS: In 18 ILVT patients, non-inducible/nonsustained VT and those unable to tolerate VT, a linear lesion along the mid to inferior septum was placed perpendicular to the long axis of the ventricle, approximately midway to one-third from the base to the apex in the region where the Purkinje potentials (PP) were recorded during sinus rhythm. RESULTS: During a follow-up of 22.8±12.6 months (range: 3-35 months), there were three recurrences of tachycardia in the 18 patients (16.7%). Long-term achievement ratio was 83.3% with no permanent complications. CONCLUSIONS: Linear ablation in the septum of the LV as a substitute mapping strategy was effective and safe in ILVT patients, noninducible/nonsustained VT and those unable to tolerate VT.