Endoventricular Electromechanical Mapping—The Diagnostic and Therapeutic Utility of the NOGA® XP Cardiac Navigation System

Abstract

Combined analysis of the electrical and mechanical function of the heart holds promise as a means of acquiring a better understanding of a variety of cardiac diseases that ultimately may lead to heart failure. The NOGA XP Cardiac Navigation System is a unique, nonfluoroscopic, catheter-based technology that achieves real-time acquisition of three-dimensional, endoventricular electromechanical maps. Through the provision of point-by-point measurements of endocardial electrical activation and voltage and mechanical shortening, electromechanical mapping has been evaluated for its ability to identify regional myocardial ischemia and characterize tissue viability. A decade of preclinical and clinical research has verified its safety and feasibility and raised the possibility of its application as a diagnostic adjunct to conventional angiography in the catheterization laboratory. However, this role has not yet been realized outside of the research setting. Instead, a more prominent niche for NOGA XP has emerged as a therapeutic tool for guiding direct myocardial interventions, most notably the targeted administration of regenerative therapies (e.g., cells, genes) to the heart. In this review, we discuss the fundamental aspects of this electromechanical mapping system and the evidence for both its diagnostic and therapeutic utility.

Assessment of myocardial fibrosis by endoventricular electromechanical mapping in experimental nonischemic cardiomyopathy

“…In our preclinical model of anthracyclineinduced cardiomyopathy, LV mapping revealed multisegmental electrical and mechanical dysfunction compared to healthy myocardium. Moreover, endocardial voltage and shortening data showed reasonable capacity for identifying myocardial segments with increased fibrosis burden, with threshold values and accuracy rates that are compatible with previous experience in IHD [12].…”

“…Thereafter, points were sampled from each region of the chamber without fluoroscopy. Endocardial-catheter tip contact and stability were verified at each site using well-described criteria, based on point loop stability, location stability, cycle length stability and local activation time stability [12]. Point sampling was performed with the map displaying local activation times, with fill threshold 15 mm.…”

“…Regional mechanical function was represented by the linear local shortening ratio (LLS), which was determined by a validated formula that averages the change in distance between an index point and all its recorded surrounding points from late diastole to maximum systole [12,18]. To account for non-uniformity of sampled points, the formula incorporates a weighting function to emphasize points within a distance of 8-15 mm.…”

“…The NOGA Ò XP system automatically determined the long axis of the reconstructed LV as the line connecting its center of mass to its designated apical point. The nine segments were obtained by dividing the long axis into three longitudinal areas (distal (20%), mid (40%) and base (40%)), and then the mid and basal levels into anterior (80°), septal (120°), lateral (80°) and posterior (80°) segments [12,14,19] (Fig. 1).…”

“…Direct intramyocardial intervention can be achieved via a percutaneous, transendocardial approach, using the catheter-based NOGA Ò XP Cardiac Navigation System (Biologics Delivery Systems Group, Cordis Corporation, Diamond Bar, CA, USA) (reviewed in [12]). NOGA Ò XP creates three-dimensional (3D) map reconstructions of the LV by sampling electromechanical information from multiple endocardial sites.…”