IDF
We used the BeeATⓇ catheter and a dedicated
defibrillator (Shock ATⓇ, Japan Lifeline, Tokyo,
Japan). which together constituted the IDF system approved for use in
Japan (Figure 1 ). The BeeATⓇ catheter has 20
poles consisting of a distal set of 8 poles, middle set of 8 poles, and
proximal set of 4 poles. The distal 8 poles are positioned in the distal
CS and middle 8 poles along the lateral wall of the right atrium (RA).
The proximal 4 poles are positioned in the superior vena cava (SVC) and
record the SVC activity during the procedure. We selected the catheter
sizes (S, M, and L) to fit the LA and RA size of the patients.
Cardioversion was effective with a current delivery between those distal
and middle sets of electrodes, but they were also able to record the
local electrograms.
For cardioversion, a biphasic direct current was delivered between the
distal set and the middle set of electrodes synchronized to the R wave
of the body surface electrocardiogram. If cardioversion was not
possible, we changed the lead of the body surface electrocardiogram to
detect and synchronize to any R wave. We started the IDF output at 1 J
and went up to 3, 5, 10, 15, 20, and 30 J. The maximum energy output was
30 J with this system. We performed IDF under deep sedation with
propofol and dexmedetomidine. When the blood pressure was low, we used
phenylephrine.