Pleomorphic Ventricular Tachycardias in Nonischemic Cardiomyopathy.

Compared to patients with prior myocardial infarction, mapping and ablation of ventricular tachycardia (VT) in nonischemic cardiomyopathy (NICM) patients represents a unique challenge, often with non-endocardial myocardial substrate, multiple VT morphologies, and higher incidence of arrhythmia recurrence post-ablation. Multi-modality imaging and detailed electroanatomic mapping demonstrated two predominant regional scar distributions: basal inferolateral and basal anteroseptal locations. Among the latter group, patients with predominantly septal scar pose a particularly difficult subset. Careful and systemic mapping is required to define the VT substrate. Aggressive ablations are often required from both sides of the septum to achieve arrhythmia control.