Ablation of idiopathic ventricular arrhythmias originating from basal cardiac crux region

Background Ablation of idiopathic ventricular arrhythmias (VAs) in the cardiac crux region is one of the challenging procedures due to the complex anatomical structure where the four chambers of the heart are offset. Although this region is complex, the contiguous cardiac structures allow for the ablation of arrhythmias from adjacent sites. Case presentation We present different anatomical approaches in radiofrequency ablation and the ECG characteristics from a case series of VAs originated from the basal inferior ventricular septum, the corresponding endocardial aspect of the basal cardiac crux region. Conclusions Ablation of VAs originated from the basal cardiac crux region requires detailed mapping in the proximal coronary venous system and the adjacent structures including the RV, RA, and LV. In addition to the characteristic ECG of basal crux VAs, our three cases present an abrupt precordial transition in V2 with R wave amplitude greater than in V1 and V3.