Figure 4 Twelve lead ECG recorded during antidromic AV re‐entrant tachycardia using a right atriofascicular (Mahaim) accessory pathway for antegrade conduction. These pathways are typically located along the endocardial surface of the right ventricular free wall with the distal insertion in the apical region of the right bundle branch. Differential diagnosis includes a ventricular paced rhythm as the majority of ventricular pacing leads are situated in the right ventricular apex.