CA and ICE
All the patients were administered oral anticoagulants more than 3 weeks
before CA. Novel oral anticoagulants other than dabigatran were changed
to dabigatran on the day of surgery and the day following CA. If the
anticoagulants used were dabigatran or warfarin, their intake was
continued throughout the perioperative period. CA was performed under
general anesthesia. Activated clotting time (ACT) was measured using
blood samples obtained venously every 15-30 min during the procedure;
this value was maintained at 300-350 s using unfractionated heparin. An
ICE probe (ViewFlex Xtra ICE catheter, Abbott Laboratories, Illinois,
USA or ACUSON AcuNav, Johnson and Johnson, New Jersey, USA) was inserted
from the right or left femoral vein through a long sheath (SL0, Abbott
Laboratories, Illinois, USA). After the transseptal approach, we placed
the ICE probe in the LA, and the probe was turned to scan the entire LA
and LAA before CA performance in the LA. The LAA was visualized from the
body of the LA. If there was no thrombus in the LAA, CA was performed.
Meanwhile, if a thrombus was suspected on ICE, CA in the LA was
abandoned. The thrombi evaluated by ICE were defined as circumscribed
and uniformly echo-dense intra-cavity masses distinct from the
underlying endocardium and pectinate muscles.
Using the ICE probe, the velocity of blood flow was estimated inside the
LAA. These data were obtained using pulse-Doppler imaging. Sample
volumes were positioned within 1 cm of the orifice of the LAA and the
velocities were assessed during AF. The peak emptying velocities of the
LAA were averaged over a minimum of five consecutive cardiac cycles
(with each R-R interval).9
Three-dimensional CT (3DCT) of the LA was made of images of early-pCT
for LA reconstruction. These LA images were merged with a 3D mapping
system during CA.
We also assessed the presence of symptomatic stroke events during the
perioperative period.