Premature ventricular contractions with two QRS morphologies originate from one focus in great cardiac vein

Two apparently remote types of ventricular tachycardia from a single right bundle branch focal source

“…A single focal source manifesting as VA with alternating QRS morphologies has been described in other cardiac locations 2 and specifically in the left ventricular papillary muscles 3 . These thick myocardial structures comprising complex separated myocardial strands on the basal and apical sides facilitate anisotropic conduction and alternating impulse propagation from deeper layers in different directions; however, entirely opposite QRS axes were not usual 3 …”

High‐density mapping to guide ablation of a right bundle branch morphology premature ventricular contraction from the right outflow tract

“…Some authors have reported that VTs originating from one focus in the LVS can present with multiple morphologies due to different exit sites . PVCs from this area are often targeted from the CS system (AIV/GCV) but can also be accessed directly via pericardial puncture.…”