Three-Dimensional Mapping to Guide Optimal Catheter Position in Cardiac Resynchronization Therapy

Contractile dyssynchrony due to intraventricular conduction delay diminishes systolic function and is a major independent risk factor for worsening heart failure. Cardiac resynchronization therapy (CRT) is a relatively new treatment that employs a biventricular pacemaker to re-coordinate contraction in ventricles with conduction delay. Although it is highly effective in many patients, approximately 35% do not respond to the therapy. Even when the "right" patient is selected for CRT using inadequate baseline predictors of responsiveness, stimulating the "wrong" left ventricular (LV) site remains an important cause ofnon-response to CRT. As the underlying disease substrate can vary widely from patient to patient, employing a "one size fits all" strategy has raised skepticism. In this chapter,we review the potential role of mapping both the electrical and mechanical myocardial substrate to enable personalized lead placement for CRT implementation. This edition first published 2013