Computed tomography and CA
CT was performed during the AF
rhythm and ICE was used to visualize the LAA in all the patients. No CD
was found in both the early and late phases in 260 patients (86%). Of
the 40 patients who exhibited CDs on early-pCT, 34 (11%) did not have
them during the late phase (Figure 1). The average dose length product
was 2166.22±224.27 mGycm, which of those only in the early phase was
1084.88±114.25 mGycm and those in the late phase was 1031.34±133.46
mGycm. The total contrast medium which used for CT scanning was
1810.46±384.95 mg of Iopamiro.
Among the 294 patients without a
CD on late-pCT, CA was performed on schedule. The absence of thrombus
was reconfirmed using ICE performed from the LA (Table 2). In one
patient, the LAA could not be visualized clearly from the body of the
LA. The ICE was inserted into the left superior pulmonary vein, which
enabled to observe the whole LAA.
CDs existed in both the early and late phases of pCT in the remaining
six patients (2%, Figures 2A and 2B). None of the patients showed CDs
only on late-pCT. There CDs were located at the entrance of the LAA in
1, outer edge in 2, inner edge in 2 and the residual LAA portion after
LAA clipping in 1. In these six patients, CA was cancelled, and the type
of anticoagulant was changed or the dose was increased in the case of
warfarin use. Follow-up CT was performed after 3-7 months. We observed
CD disappearance on subsequent late-pCT under the same CT conditions
(Figure 2C); following this, CA was performed. The absence of thrombi
was confirmed using ICE in all six patients. Among them, four patients
were also performed TEE after the CT scanning, and thrombi were observed
in all patients. One of six patient with CDs in both the early and late
phases required two changes in the anticoagulant used for CD
disappearance (Figure 3); in the remaining five patients, the
anticoagulant type was altered once.
In the whole population, six patients had also undergone CT in the
supine position (sCT) within 3 days before pCT and CD presence was
suspected. These CDs disappeared on late-pCT in three patients (Figure
4) and no thrombus was detected on ICE during CA, as mentioned
previously.
ICE imaging was performed during the AF rhythm in all patients. The
average duration between first CT scanning to catheter ablation was
9.4±7.5 days. The first subsequent CT in patients with CDs was performed
in median 68 (38-131) days, and for one patient, another CT was needed
for the disappearance of a contrast defect 58 days after seconds CT
scanning (Figure 3D). None of the patients had complications related to
CT, and no symptomatic stroke events were observed during the
perioperative period of CA.