The LAP evaluation and ASV support
The atmospheric pressure was set as 0 mmHg reference at a beginning of
the procedure. After the transseptal puncture and insertion of the 15 Fr
long sheath (FlexCath) in the LA, the LAP via the sheath was recorded on
a digital polygraph (RMC-5000, Nihon Corden, Tokyo, Japan)
(Figure 1 ). The LAP was measured over more than three
consecutive respiratory cycles. The LAP during one respiratory cycle was
calculated as the average of the integral LAPs during one respiratory
cycle, and the LAP was defined as the average value of that over three
or more consecutive cycles. The LAP during the inspiratory and
expiratory phases also was defined in the same manner. The lowest LAP
was the minimum LAP during those respiratory cycles. Afterward, the ASV
treatment was initiated in all patients. As the setting for the ASV, an
expiratory positive airway pressure of 5 cmH2O and
inspiratory pressure support between 3 and 10 cmH2O were
used. Following the ASV treatment and confirmation of stable breathing
synchronized with the ASV, the LAP was re-measured.