Abstract 15366: A Novel Non-Fluoroscopic 4D Navigation System Can Identify Differences in Mechanical Activation Patterns Between Patients With Impaired and Normal Systolic Function
Objectives: Optimal LV lead placement and device programming in CRT require an understanding of LV mechanical dyssynchrony. We examined mechanical activation patterns using a novel non-fluoroscopic 4D navigation system (MediGuide™, St. Jude Medical [SJM]).
Methods: Patients (pts) with either systolic dysfunction (SD) or normal systolic function (NSF) indicated for EP procedure underwent LV mapping during sinus rhythm. Real-time position of MediGuide sensor-enabled catheters was projected onto pre-recorded cines and used to create motion maps from uniformly distributed endocardial points. Voltage maps (EnSite™, SJM) were created from the same map points (MPs). We defined hypokinesia as maximum inward radial motion ≤3mm, dyskinesia as purely outward motion, and scar as voltage ≤0.5mV. We compared direction of motion in 4 quadrants (Q) of cardiac cycle.
Results: Motion and voltage mapping were performed successfully in 3 SD pts (67±13yo, EF 17±3%, QRS 177±35ms, 101±25 MPs/pt) and 3 NSF pts (58±3yo, EF 61±8%, QRS 81±1ms, 68±10 MPs/pt). Representative motion maps are shown (Fig. A). Compared to NSF pts, SD pts exhibited greater motion impairment (8.4±4.1% vs. 3.6±3.3% dyskinetic MPs; 41.7±1.6% vs. 11.6±4.8% hypokinetic MPs; 50.0±5.6% vs. 84.8±4.7% normokinetic MPs) and higher scar burden (20.1±7.8% vs. 1.9±2.2%). SD pts also showed larger variability in direction of motion, indicating reduced synchrony (Fig. B). In particular, LV contraction was less synchronous in SD pts with fewer inward MPs during first half of cardiac cycle (Q1: 69.4±7.1% vs. 91.6±6.1%; Q2: 50.0±19.0% vs. 82.3±7.0%) and LV relaxation was less synchronous with fewer outward MPs during second half of cardiac cycle (Q3: 61.4±16.4% vs. 93.0±6.3%; Q4: 36.7±32.8% vs. 56.2±8.4%).
Conclusions: MediGuide motion mapping identified differences in mechanical activation patterns in pts with impaired vs. normal systolic function, suggesting applicability of MediGuide for CRT guidance.
- © 2013 by American Heart Association, Inc.