3.4 Performance of conventional interrupted vs. continuous
implantation technique
Excellent pacing performance was demonstrated in all patients (see table
1).
In the validation-group, conventional interrupted implantation leaded to
successful LBBAP at first attempt in 7 patients (70%). Failure of
success at first attempt was caused by difficulties in further
progression of the lead, after initial penetration of the helix into the
RV septum. By interruption after the initial rotations, loss of torque
and momentum occurred, preventing further penetration and progression of
the lead through the septum.
At final position, 6/10 patients (60%) had non-selective capture of the
LBB, in the other 40% selective capture could be reached.
In the feasibility-group, continuous uninterrupted lead deployment
leaded to successful LBBAP at first attempt in 18 patients (90%), at
second (1 patients, 5%) or third attempt (1 patient, 5%). Failure of
success at first attempt was exclusively due to suboptimal orientation
of the sheath, impeding a good initial penetration of the helix into the
RV septum. Small corrections in the position of the sheath enabled easy
implantation of the lead in patients with a first failed attempt. At
final position, 6/20 patients (30%) had non-selective capture of the
LBB (p=0.77 vs validation-group), in the other 70%, selective capture
could be reached (p=0.584 vs validation-group). No significant
differences between the validation and feasibility-groups were observed
for the paced QRS duration (median QRSd 116ms [IQR109-134ms] vs
median QRSd 120ms [IQR 113-144ms] respectively, p=0.4018). However,
the pLVAT tended to be longer in the validation compared to the
feasibility-group without reaching significance (median pLVAT 87ms
[IQR 72-100] vs median pLVAT 73ms [IQR 69-80], respectively,
p=0.0577). Bipolar pacing thresholds at final position were
significantly lower in the feasibility-group compared to the
validation-group (mean threshold 0.81 ± 0.4 V vs 1.17 ± 0.4 V,
respectively, p=0.0253) with comparable median bipolar sensing 6.5mV
[IQR 4.6-9.5] in the feasibility group vs 9.9mmV [IQR 6.5-14] in
the validation-group, p=0.0615) and mean impedance values (624 ± 101 Ohm
in the feasibility-group vs 645 ± 74Ohm in the validation-group,
p=0.4339). Total (skin to skin) fluoroscopic dose for device
implantation was similar between groups with mean DAP 3110 ± 1587
mGycm2 in the validation-group, compared to 2793 ±
4079 mGycm2 in the feasibility-group (p=0.1405).