Radiofrequency ablation of ventricular arrhythmia from the non-coronary cusp]

There is a close anatomical relationship between the non-coronary aortic cusp (NCC) and sites where His bundle (HB) is recorded in the right ventricle (RV). We describe a patient with frequent premature ventricular beats originating near HB. Arrhythmia was successfully ablated from the NCC although local electrogram preceded QRS in NCC and His area. When RV mapping reveals an earliest ventricular activation in the HB region, mapping in the right coronary cusp and NCC should be done to identify the area of arrhythmia origin.