Ventricular Arrhythmias Originating from the Papillary Muscles of the Left Ventricle in the Structurally Normal Heart and the Role of Catheter Ablation: Ventricular Arrhythmias from the Papillary Muscles

Ventricular arrhythmias arising from the left ventricular papillary muscles, having a right bundle branch block (RBBB) QRS morphology on the electrocardiogram, account for approximately 15% of arrhythmias in a structurally normal heart and have usually a benign prognosis. The mitral valve usually has two papillary muscles, anterolateral and posteromedial, with the latter one being always more arrhythmogenic. These arrhythmias are not typically inducible by programmed ventricular or atrial stimulation, suggesting a non-reentrant mechanism. Ventricular arrhythmias originated from the papillary muscles should be distinguished from other idiopathic left ventricular arrhythmias such as fascicular or mitral annular arrhythmias, which also have a RBBB pattern. Catheter ablation in these cases is always challenging and the recurrence risk is higher compared to other idiopathic ventricular arrhythmias. Rhythmos 2021;16(1):7-10