- Ventricular tachycardia (VT) and premature ventricular contractions (PVCs) originating in the vicinity of the His-bundle region represent 3%–9% of all idiopathic ventricular arrhythmias (VAs).1,2 In addition, patients with cardiomyopathies and scar-related VT may exhibit septal arrhythmogenic substrate involving the parahisian region.3 Catheter ablation of these arrhythmias poses particular challenges because of the risk of inadvertent atrioventricular (AV) block, and a systematic approach is important to improve outcomes and minimize complications.
- The papillary muscles (PMs) are a source of ventricular arrhythmias (VAs) in both structurally normal and abnormal hearts. Presentation includes isolated premature ventricular contractions (PVCs), nonsustained ventricular tachycardia (VT), and sustained recurrent VT. In addition, PVCs arising from the PMs may play a role as triggers of ventricular fibrillation (VF).1,2 Because of their highly variable and complex anatomy and independent motion during the cardiac cycle, catheter ablation is challenging, with lower procedural success and higher recurrence rates compared with other locations.
- Catheter ablation of idiopathic ventricular arrhythmias (VAs) is highly successful, with overall cure rates >90%, and is accepted as a first-line therapy by current guidelines.1 However, despite the advances in mapping and ablation techniques, there is a percentage of patients in whom successful ablation cannot be achieved because of anatomic limitations. In this regard, one of the most challenging clinical problems that electrophysiologists may face in the laboratory is the approach to VAs arising from the summit of the left ventricle (LV).