Abstract
A 65 year-old with history of prior ablations for regular narrow QRS
short- RP tachycardia presented with recurrence of palpitations. An
electrophysiological study showed long VA tachycardia with concentric
atrial activation with a left ventricular origin extrastimulus delivered
during His refractoriness, advancing the next ‘A’.
A HRVPB can only reset an ORT if it ‘pulls in’ the local V at the
ventricular insertion of an accessory pathway. As showcased in this
case, erudite analysis of the pattern of perturbation of local
ventricular electrograms is of paramount significance when interpreting
responses to this maneuver. This concept when fortified with a
heightened index of clinical suspicion for mitral annular block,
anatomical knowledge of the pattern of LA-CS muscular connections, and
pathway orientation, led to accurate electrophysiological diagnosis and
management.
Keywords- Short RP tachycardia, concentric atrial activation, His
refractory Ventricular premature beat, mitral annular block