Mechanisms of Cardiac Implantable Electronic Device Interference With the Tricuspid Valve Apparatus

Cardiac implantable electronic devices (CIEDs) have been implicated in the development of tricuspid valve (TV) dysfunction. However, the mechanisms of dysfunction are not well characterized. We sought to define the prevalence, location and mechanisms of CIED-TV interference based on direct inspection of gross pathologic specimens from consecutive patients with CIEDs who had undergone orthotopic heart transplantation (OHT). CIED-interference was classified by location (septal, posterior or anterior trigone of the RV), portion of TV apparatus involved (leaflet(s) only, sub-tricuspid apparatus (STA) only or a combination of both leaflet and STA) and type of interference (adherence, trapping or both). Sixty-two cases of CIED-TV interference were identified (5 leaflet, 30 STA and 27 leaflet and STA). The majority of patients had nonischemic cardiomyopathy (81%) and leads in situ for <10 years (77%). Most CIED-TV interference involved either the posterior (n = 23, 37%), septal (n = 15, 24%) or posteroseptal regions of the RV (n = 16, 26%). Interference with the anterior leaflet or anterior STA was rare. STA interference consisted of lead trapping behind the papillary muscles or chordae alone (n = 6), lead adherence with trapping (n = 21) and lead adherence alone (n = 3). Combination STA and leaflet interference consisted of adherence and trapping (n = 20) and adherence without trapping (n = 7). In conclusion, CIED-TV interference occurs most frequently with the STA in the posterior and septal regions of the RV. These findings have the potential to instruct imagers on how to evaluate for CIED-TV interference in an era where, elucidating the mechanism of TV dysfunction and considering options for repair is gaining momentum.