IDF and AF
Some reports have assessed the efficacy and safety of transvenous
internal atrial cardioversion performed in patients with persistent
AF.14, 15 The IDF is an effective procedure for
restoring SR in patients with AF.6 Further, there are
few complications with IDF. Boriani G etc. reported myocardial injury
following repeated internal atrial defibrillations.16Although, minor elevations in the troponin I level were detected, it
suggested minor asymptomatic myocardial injury. There was no
relationship between an elevated troponin I level and the number of
shocks or amount of energy delivered. Therefore, the
BeeATⓇ catheter and dedicated defibrillator could be
used multiple times for IDF, and because of that they are useful for
checking triggers. The maximum energy output of this system was 30 J.
Although the mean number of IDFs was 9.1 ± 7.5 times (max 28 times) per
RFCA procedure, there were no complications associated with the IDF in
our study. All patients were restored to sinus rhythm by the IDF with an
output of less than 30 J.
The electrode position for the outcome of the IDF was very important.
Thus, low-energy biphasic shocks positioned between the RA and CS were
effective for cardioverting AF. The distal 8 poles of the
BeeATⓇ catheter were positioned in the distal CS and
the middle 8 poles along the lateral wall of the RA. We selected the
different catheter sizes (S, M, and L) to fit the LA and RA size of the
patients. Therefore, an appropriate IDF could be performed in this
study. Furthermore, the IDF was less affected by the LA size than by an
external defibrillation catheter that fit the LA
size.6