Ventricular tachycardia with different QRS morphologies arising from single origin

A 63-year-old woman was referred with ventricular tachycardia (VT). Electrocardiogram before admission indicated VT originating from right ventricle outflow tract (RVOT) (A), but another kind of VT was also induced. Electrocardiogram indicated it originated from left ventricle outflow tract or mitral annulus (B). Mapping in left ventricle and aortic sinus could not find the origin. QRS morphology of pace mapping in RVOT was similar to the second VT [C, blue dotted rectangle represents pacing QRS in RVOT, red dotted rectangle represents spontaneous VT, and black dotted rectangle represents pacing QRS in aortomitral continuity (AMC)]. Activation mapping indicated the earliest part of this VT originated from RVOT (D). Ablation in RVOT terminated the VT successfully (E, F). Three-dimensional reconstruction computed tomography and echocardiography were normal. Therefore, we suspect that a fibre connected RVOT and AMC leading to two outlets of a single VT (G). Conflict of interest: none declared.