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.