Case Report:
A 40-year-old man was admitted to our institution because of paroxysmal
atrial fibrillation. At the age of 24, he had been diagnosed with a
secundum ASD, which was 19mm in diameter with the left to right shunt
and was corrected with percutaneous atrial septal defect closure. During
the last 7 years, the patient complained of palpitations, and a
follow-up electrocardiogram demonstrated the atrial flutter in September
2016. A further electrophysiological mapping revealed the CTI-dependent
atrial flutter. Subsequently, he had undergone the tricuspid isthmus
ablation. His symptoms were relieved but reported with transient
palpitations sometimes. AF was diagnosed on an electrocardiogram in
2019, and the patient then opted for AF ablation. The patient had
undergone 1 attempt to perform AF ablation in 2019, and TSP which was
attempted initially at a site posteroinferior to the ASD occlude guided
by intracardiac echocardiography (ICE) failed. Moreover, the occluder
with 11mm thickness and a 34 mm diameter, which was oversized with
respect to the native interatrial septum further increased the risks of
direct TSP through the occluder. Finally, the ablation was terminated
due to unsuccessful access to the LA. The patient’s paroxysmal atrial
arrhythmias were treated initially with propafenone, followed by
dronedarone. However, AF became aggravated and the condition transformed
into a drug-refractory stage. The patient was referred to our
institution for a second attempt at LA ablation.
The LA ablation procedure was performed under general anesthesia. An ICE
was performed to rule out the left atrial appendage thrombus and for
visual assistance during transseptal puncture. A 7-F multipolar
electrode catheter was placed in the coronary sinus via the left femoral
vein. TSP using a Brockenbrough needle was guided by fluoroscopy and
ICE. We performed the direct TSP through the occluder device
posteroinferior to its waist. Initially, the transseptal needle
succeeded to traverse the device confirmed by contrast injection and a
guidewire was positioned in the left superior pulmonary vein. Repeated
attempts to pass through the 8.5F
long sheath into the LA were
unsuccessful because of significant resistance induced by severe
fibrosis, which indicated a change to be made in the strategy. We could
successively advance a 2.0-, 3.0-, 4.5-mm percutaneous coronary
intervention (PCI) balloon over the guidewire across the septum.
Moreover, the position of the non-compliant balloon on either side of
the septum was confirmed by fluoroscopy and ICE, which also ensured that
the balloon was placed perpendicularly to the transseptal access site
created by the needle and the dilator. The sequential dilatation was
performed by an inflation pressure of up to 12atm, whereas the thickened
occluder prevented the balloon from further enlarging the access site.
The PCI balloon was then withdrawn and a Passeo-35 (Biotronik AG )
peripheral balloon with a 6mm diameter was advanced through the puncture
site. Subsequently, we inflated the peripheral balloon to its maximum
size as the inflation pressure reached 10 atm. Finally, the 8.5F
transseptal sheath could easily be passed into the mid-cavity of the LA
without any resistance. After successful TSP, the patient was
continuously anticoagulated by intravenous heparin to maintain an
activated clotting time of 250-300 seconds. A saline-irrigated ablation
catheter was then advanced through the sheath, and the patient could
tolerate the procedure well without any further complications. An
electroanatomical mapping was made of the LA and pulmonary veins and
showed successful isolation of the pulmonary veins. The total procedure
time and transseptal time were 360 minutes, and 215 minutes,
respectively. No interatrial shunt or device deformation was seen and
was confirmed by ICE at the end of the ablation procedure and by the
transthoracic echocardiography the next day. At 3 months of follow-up,
the patient remained in sinus rhythm and showed no residual shunt.