“…Figures 1, 2, and 3 highlight common findings and principles in our series of cases. In all cases, the following observations were noted: (1) a reentrant mechanism for VT was confirmed by fulfilling at least one entrainment criteria; 16 (2) initial, spontaneous, clinical VT was noted to have RBBB QRS with left superior (LS) axis, although Cases 5 and 6 additionally had spontaneously shifting VT morphology to RBBB with right inferior (RI) axis; (3) FP preceded QRS in all VT forms that did not exhibit left bundle branch block (LBBB), and changes in the tachycardia cycle length (TCL) were preceded by changes in FP‐FP timing; (4) in non‐LBBB VT morphologies, entrainment pacing from the right ventricle (RV) or from the right bundle branch (RBB) resulted in a postpacing interval (PPI) that was greater than 30 milliseconds compared with the TCL, excluding the RBBB as part of the circuit.…”