Relationship between mechanical dyssynchrony and intra-operative electrical delay times in patients undergoing cardiac resynchronization therapy

• Type of Material: Article
• Authors: Jonathan D Suever, Georgia Institute of Technology; Gregory R Hartlage, Emory University; R Patrick Magrath III, Georgia Institute of Technology; Shahriar Iravanian, Emory University; Michael S Lloyd, Emory University; John Oshinski, Emory University
• Language: English
• Date: 2014
• Publisher: BioMed Central
• Publication Version: Final Published Version
• Copyright Statement: © 2014 Suever et al.; licensee BioMed Central Ltd.
• License: Creative Commons Attribution 2.0 Generic
• Final Published Version (URL): http://www.jcmr-online.com/content/16/1/4
• Title of Journal or Parent Work: Journal of Cardiovascular Magnetic Resonance
• ISSN: 1097-6647
• Volume: 16
• Issue: 1
• Start Page: 4
• End Page: 4
• Grant/Funding Information: Funding for this research was provided by AHA Grant-in-Aid (Oshinski), the National Science Foundation Graduate Research Fellowship Program (Suever), and by the National Center for Advancing Translational Sciences of the National Institutes of Health Award Number UL1TR000454.
• Keywords: Cardiovascular magnetic resonance; Electromechanical delay; Electrophysiology; Cardiac resynchronization therapy
• Research Categories: Health Sciences, General

Abstract

Background It is important to understand the relationship between electrical and mechanical ventricular activation in CRT patients. By measuring local electrical activation at multiple locations within the coronary veins and myocardial contraction at the same locations in the left ventricle, we determined the relationship between electrical and mechanical activation at potential left ventricular pacing locations. Methods In this study, mechanical contraction times were computed using high temporal resolution cine cardiovascular magnetic resonance (CMR) data, while electrical activation times were derived from intra-procedural local electrograms. Results In our cohort, there was a strong correlation between electrical and mechanical delay times within each patient (R2 = 0.78 ± 0.23). Additionally, the latest electrically activated location corresponded with the latest mechanically contracting location in 91% of patients. Conclusions This study provides initial evidence that our method of obtaining non-invasive mechanical activation patterns accurately reflects the underlying electromechanical substrate of intraventricular dyssynchrony. Keywords: Electrophysiology; Cardiac resynchronization therapy; Cardiovascular magnetic resonance; Electromechanical delay