Figure legends:
Fig 1 :
A: Clinical narrow QRS tachycardia (SVT1 ).
B: Baseline EGG showing absence of pre-excitation.
C: Intermittent wide QRS morphology with RBBB and right axis deviation. TCL and HV interval was same as SVT 1.
D: 12 lead ECG morphology of wide QRS tachycardia. Maneuvers proved it as AVNRT with aberrancy.