Implant procedure
Electroanatomical mapping was used during the implant in 6 patients: 4
with cc-TGA (1 with additional dextrocardia and 1 with a double switch
operation), 1 with D-TGA and atrial switch operation (Senning) and in 1
patient with repaired VSD in order to identify the HB area and to
delineate the anatomy (Figure 1).
Overall, acute implant success defined by HBP or LBBAP criteria was
100%. HB pacing was attempted in 14 patients (6 patients with cc-TGA, 3
Tetralogy of Fallot, 2 with a repaired VSD, 1 patient with D-TGA and a
Rastelli correction, 1 with Ebstein’s anomaly and 1 with AV canal) and
was successfully achieved in 10 (71%). The 4 patients with unsuccessful
HBP underwent LBBAP. In the remaining 6 patients LBBAP was used as the
primary implant strategy. Strict LBB capture criteria were present in 5
patients and these patients were deemed to have LBBP while the remaining
5 patients were defined as LVSP with a significant reduction in final
paced QRS width (figure 2). The time employed for the CSP lead implant
widely varied ranging from 4-115 minutes with a mean of 31±28 min. The
mean total implant procedure duration was 126±82 min.
A standard C315 His sheath was used first in all patients except one in
which a C315S sheath was employed. Additional sheaths (C304 or others)
were used in 10 patients (50%) due to difficulties in either localizing
or achieving stable positions with the C315 His sheath. However, at the
end, a C315 His or C315S sheath was used for definitive lead deployement
in 14 patients (74%) and a C304 sheath was used for lead fixation in 4
patients. In 1 patient (D-TGA and large VSD corrected with a Rastelli
surgery) a standard active fixation lead (Solia S53, Biotronik) was
finally used with a previously preformed stylet to get access to the HB
area resulting in a successful implantation. In patient #11 with a
cc-TGA and a double switch operation a Attain Command 6250V-3D sheath
was used for lead delivery. Table 2 summarizes the principal baseline
characteristics and implant details for each patient.