2.4 Uninterrupted LBBAP implantation guided by continuous
unipolar LS pacing
Twenty patients were implanted using the novel uninterrupted pace
mapping technique (feasibility-group). First, pacing cables were
connected to the LS (cathode) and to the patient’s body (anode) with the
LS fully advanced to the tip of the lead (Figure 1B). Implantation was
then performed by uninterrupted manual clockwise rotations of the outer
lead body, while pacing continuously at 5V output from the LS at 100bpm
(or 10bpm over the patient’s rhythm if the patient’s rhythm was faster).
During implantation, 12-leads ECG was recorded to monitor QRS changes
(with a particular attention to V1 and V6, highlighted and magnified on
the EP recording system). Rotations were continuously delivered until a
right bundle branch block (RBBB) morphology was obtained in V1. Triggers
and callipers were set on the EP recording system for continuous
monitoring of the QRS duration (from pacing artifact to end-QRS) and
pLVAT (from pacing artifact to peak R-wave in V6). Rotations were
continuously delivered until right bundle branch block (RBBB) morphology
was obtained in V1 with a targeted pLVAT value of <85ms (for
narrow native QRS) or <100ms (for wide native QRS or a
complete AV block at baseline). Beat-to-beat pacing impedance displayed
on the programmer was simultaneously filmed for off-line analysis.
After continuous lead deployment, final paced QRS duration and pLVAT
(measured from pacing stimulus to peak of the R wave in lead V6) were
recorded and no further advancement of the lead was performed.