Index procedure: EIVM
After written consent was obtained, procedures were performed under
general anesthesia and uninterrupted anticoagulation (uninterrupted
direct oral anticoagulants and vitamin-K antagonists with an
international normalized ratio target of 2–3, 120 U/kg of intravenous
heparin given after femoral puncture for activated clotting time target
> 300). EIVM was performed as described.9Briefly, after transseptal access and high-density LA bipolar voltage
mapping performed during sinus rhythm (SR), AF or LA flutter, the CS was
cannulated with a standard SL0 or a steerable Agilis sheeth. To
visualize the VOM ostium, non-selective CS angiography (anteroposterior)
was performed with a multipurpose coronary angiography 5F LIMA catheter.
When the VOM ostium could not be seen, selective CS angiography with a
Swan-Ganz balloon catheter was performed at the median and proximal CS
with 30° left and right anterior oblique views. The VOM was cannulated
with the LIMA catheter and a straight Whisper guidewire (Boston
Scientific, Marlborough, MA) was inserted in the Marshall venous network
over a 2.00- to 6.00-mm MiniTrek balloon angioplasty catheter (Abbott,
Chicago, IL). After VOM balloon occlusion, injections of 3 mL of 96%
ethanol were administered sequentially, separated by injections of 3 mL
contrast agent, until an aspect of the LA myography was seen, indicating
ethanol penetration into the LA myocardial tissue.