Agreement on site of latest electrical activation between right ventricular pacing and intrinsic conduction as target for left ventricular lead position in cardiac resynchronization therapy.

BACKGROUND

In cardiac resynchronization therapy (CRT), studies indicate that targeting the left ventricular (LV) lead toward the site of latest electrical activation could improve clinical outcomes. Whether this site should be determined during right ventricular (RV) pacing or intrinsic conduction is unknown.

OBJECTIVE

The study sought to investigate agreement between RV pacing and intrinsic conduction in identifying the site of latest electrical activation in patients undergoing CRT.

METHODS

During CRT implantation, we obtained pairwise measurements of the interval from QRS onset to local LV activation during intrinsic conduction (Q-LV) and the interval from the paced signal on the RV lead electrogram to the sensed local LV activation during RV pacing (RV-LV) in the basal, mid, and apical positions of eligible veins in patients randomized to the intervention arm in the DANISH-CRT (Does Electric Targeted LV Lead Positioning Improve Outcome in Patients With Heart Failure and Prolonged QRS) trial. Venous anatomy and final lead positions were verified by computed tomography.

RESULTS

We included 61 patients and measured intervals in 209 veins with 531segments. We found substantial agreement between RV-LV and Q-LV in identifying the latest activated vein (Cohen's weighted kappa coefficient 0.69 [95% confidence interval 0.62-0.76]). The RV lead was predominantly positioned toward the anteroseptal region and RV-LV favored a posterior vein more often than Q-LV. We found high intra- and interobserver reliability for RV-LV and Q-LV measurements.

CONCLUSION

There is substantial agreement between RV-LV during RV pacing and Q-LV during intrinsic conduction in identifying the optimal target for LV lead position in CRT. Still, the optimal target vein changed for one-third of patients as RV-LV favored a posterior target vein more often than Q-LV.