Catheter Ablation of Idiopathic Epicardial Ventricular Arrhythmias Originating from the Vicinity of the Coronary Sinus System.

Catheter Ablation of Idiopathic Epicardial Ventricular Arrhythmias. Idiopathic epicardial ventricular arrhythmias (IEVAs) originating from the vicinity of the coronary sinus system are not uncommon, accounting for about 9% of idiopathic ventricular arrhythmia cases. IEVAs share clinical presentation and electrophysiological characteristics with ventricular arrhythmias arising from the right ventricular outflow tract possibly as manifestations of cAMP-mediated triggered activity and delayed after-depolarizations. Detailed analysis of standard 12-lead electrocardiogram morphology by using unique variables and algorithms allows clinicians to predict probable location of epicardial foci and informs optimal catheter ablation strategy. Epicardial mapping and ablation through the coronary sinus and its branches is effective and safe, and increasingly favored. However, it is important because of the common perivascular origin of IEVAs to perform coronary angiography prior to or after ablation and to select the appropriate ablation energy form to avoid serious complications.