PO-05-043 RIGHT VENTRICULAR POSITIONING OF LEADLESS PACEMAKER MAY INFLUENCE LEFT VENTRICULAR ELECTROMECHANICAL SYNCHRONY

Leadless pacemakers (LP) reduce certain complications of conventional pacemakers, yet limitations single chamber right ventricular (RV) pacing remain, including pacing-induced dyssynchrony. The Micra LP is positioned in RV septum, avoiding the free wall to minimize perforation, and location primarily determined by capture threshold sensitivity. Whether positioning mid upper septum vs. apical affects degree left (LV) synchrony be determined. We sought establish whether position on LV synchrony, using strain imaging speckle-tracking echocardiography. Between May 2019 February 2022, 53 consecutive patients implanted with were screened. Of those, eleven found 100% paced have an adequate quality transthoracic echocardiogram (TTE) for analysis. Chest 12-lead electrocardiogram (EKG) used identify implantation site (apical high septum). focused views processed Tomtec software acquire variables ventricle mechanical dispersion (LVMD) maximal opposing delays from 18 segment model. QRS duration (QRSd) was obtained EKG. Mann-Whitney U test Fisher’s exact compare independent groups. All analyses performed SPSS Ver 29.0 (IBM Corporation, Armonk, NY). Electrical dyssynchrony measured QRSd showed a tendency longer septal group (n= 5) compared higher 6), but it not statistically significant (159.6 +/- 13.8 148.33 16.15, p = 0.302). Ejection fraction no difference between two groups (median 64 60, 0.879). Degree mitral regurgitation also (U 11.5, 0.537). Higher placement resulted improved as measure lower LVMD shorter delay 2 3, 0.017 0.03 respectively). Implantation displays speckle tracking derived strain, which positioning. This may consequences cardiac function requiring continuous pacing. Larger studies are needed determine these preliminary findings generalized larger population.