Clinical feasibility of targeted cardiac resynchronization lead delivery using a 3D MRI cardiac model

Abstract

Background Cardiac resynchronization therapy (CRT) aims to reduce dyssynchronous contraction through simultaneous pacing of the right ventricular (RV) septum and left ventricular (LV) lateral wall. Up to 40% of patients do not respond, largely attributed to lack of dysynchrony and/ or transmural scar at pacing sites. In this pilot study we tested the feasibility of guiding LV and RV leads to “optimal” segmental targets using a MRI-based 3D surface rendered cardiac model. Methods Ten consecutive patients planned for CRT were recruited. All patients underwent cardiac MRI inclusive of cine and delayed enhancement (DE) imaging using a 3T scanner. A blinded interpreter determined the time to maximal radial wall thickening (TmWT) and myocardial scar burden for each of 16 segments. All potential LV lead targets were ranked according to scar burden (lowest first) and then sub-ranked by TmWT (highest first). All potential RV lead targets were ranked according to scar burden (lowest first). These rankings were encoded onto a surface rendered cardiac model, displayed in standard fluoroscopic views (Figure 1A) and used to direct lead placement by fluoroscopy. A cardiac gated CT was then performed at a 1-month follow-up visit (Figure 1B) to assess procedural success for target achievement. Results