B-PO05-035 MICRA AV LOCATION BY CHEST X-RAY AND ITS EFFECT ON AV SYNCHRONY

Abstract

The Micra AV is a leadless pacemaker designed to provide single chamber RV pacing with rate response using an accelerometer and AV synchronous (AVS) algorithm. The Marvel studies showed that the Micra AV could achieve AV synchrony. There is little evidence that Micra AV location affects performance. To determine if radiographic location of Micra AV affects AVS. We conducted a single center retrospective analysis of patients with a Micra AV implanted from Feb-Nov 2020, n=29. AVS was defined as the percentage of time the device was atrial sensing, obtained from in-person and remote device interrogation. Two methods, using an AP CXR, were used to determine location. Method one evaluated location via simple review of the device on CXR. The second method used three reproducible points on CXR to triangulate and horizontally section the right ventricle. Compared to corresponding CT scans, these sections repeatedly and correctly delineated the area of the RVOT from mid and apical septum. We dichotomized AVS by >70% or <70%. A chi-squared test was used for comparison of groups and an ANCOVA test for adjusting for confounders. Refer to related figured. There was no linear correlation between radiographic Micra AV placement and AVS (Method 1 p=0.507, method 2 p=0.982). For >70% or <70% AVS, there was no correlation with device location. Our study suggests that Micra AV location within the RV does not affect AVS acutely or long term (via remote monitoring), which expands upon the findings of the MARVEL study. Acceptable AV sensing can be achieved agnostic to location.