50 year old woman Recurrent tachycardia Normal Echo

50 year old woman Recurrent tachycardia Normal Echo Comments from Deep Chandh Raja, Chandrashekhar, Aditya Kapoor and Anunay Gupta

Analyse- Long RP tachycardia on the left which terminates with a PVC. Varying R-R intervals; P inverted in II/III Intracardiacs at induction- D/D now? Induction by APDs (with an AVA sequence), suggesting a re-entry mechanism though does not rule out any of the D/D: 1. Atypical AVNRT, 2. Orthodromic AVRT, 3. AT. The A is equally early at CS 78 and at the His region.

Para. His pacing-helpful? Longer VA interval without His capture and shorter VA interval with His capture indicating AV nodal conduction. This maneuver may not be useful in the presence of slowly conducting AP or when the AP is remote from the pacing site VOP during tachycardia- after stopping VOP the tachycardia continues with a VAV (pseudo-VAAV) sequence. The atrial activation sequence during the tachycardia and during V pacing are similar. These make AT very unlikely.

Adenosine 6 mg. Tachycardia terminates with AV block suggesting AV node dependent tachycardia

Tachy induction again-anything unusual? Initiates with a marked VA increase and a VAV sequence. During V pace and tachy: similar retrograde A activation, makes AT unlikely. CS 78 just outside the CS os. Consistent? The variability in tachy CL makes this test uninterpretable. The HA>200 ms 340 ms 230 ms 110 ms 360 ms 370 ms

VOP during tachy again. The tachy CL is varying. The PPI-TCL & Stim A - VA interval during tachycardia the values are greater than 115 and 85 ms respectively indicating the possibility of (atypical) AVNRT. Note the varying HA intervals (the are equal). Interpret- With decremental AP, PPI-TCL and Stim-A - VA may overlap with atypical AVNRT, so confirm by VA index (here=0). This does not favour either AV nodal or inferior (posteroseptal) AP conduction. RV inflow pacing 380 ms 185 ms 170 ms RV apical pacing 170 ms

Then this was seen. Ongoing tachy with intermittent LCP block (no V). 1 PVC. The AA intervals are varying. Tachy Terminates with an A in the AV node. However, with prior AV block, this by itself does not rule out AT.

RF signal- likely site? LAO 40 , 6 o clock, Below CS os RF energy- successful elimination of the retrograde slow pathway resulting in termination of tachycardia

After ablation………. complete VA block, capture beat. The slow pathway was the only route of retrograde conduction. RF site- LAO 40