Clinical Laboratory and Pacing Predictors of CRT

Authors: Jagdesh Kandala Robert K Altman Mi Young Park Jagmeet P Singh

Publish Date: 2012/02/24

Volume: 5, Issue: 2, Pages: 196-212

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Abstract

A decade of research has established the role of cardiac resynchronization therapy CRT in medically refractory moderate to severe systolic heart failure HF with intraventricular conduction delay CRT is an electrical therapy instituted to reestablish ventricular synchronization in order to improve cardiac function and favorably modulate the neurohormonal system CRT confers a mortality benefit improved HF hospitalizations and functional outcome in this population but not all patients consistently demonstrate a positive CRT response The nonresponder rate varies from 20 to 40 depending on the defined response criteria Efforts to improve response to CRT have focused on a number of fronts Methods to optimize the correction of electrical and mechanical dyssynchrony which is the primary target of CRT has been the focus of research in addition to improving patient selection and optimizing postimplant care However a major issue in dealing with improving nonresponse rates has been finding an accurate and generally accepted definition of “response” itself The availability of a standard consensus definition of CRT response would enable the estimation of nonresponder burden accurately and permit the development of strategies to improve CRT response In this review we define various aspects of “response” to CRT and outline variability in the definition criteria and the problems with its inconsistencies We describe clinical laboratory and pacing predictors that influence CRT response and outcome and how to optimize response

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