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Cardiology Research and Practice
Volume 2011 (2011), Article ID 956062, 8 pages
Clinical Study

The Use of Epicardial Electrogram as a Simple Guide to Select the Optimal Site of Left Ventricular Pacing in Cardiac Resynchronization Therapy

Department of Cardiology, Brest University Hospital, 29609, Brest Cedex, France

Received 1 November 2010; Revised 23 December 2010; Accepted 4 January 2011

Academic Editor: Georgios Giannakoulas

Copyright © 2011 Marjaneh Fatemi et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Cardiac resynchronization therapy (CRT) has been demonstrated to improve symptoms and survival in patients with left ventricular (LV) systolic dysfunction and dyssynchrony. To achieve this goal, the LV lead should be positioned in a region of delayed contraction. We hypothesized that pacing at the site of late electrical activation was also associated with long-term response to CRT. We conducted a retrospective study on 72 CRT patients. For each patient, we determined the electrical delay (ED) from the onset of QRS to the epicardial EGM and the ratio of ED to QRS duration (ED/QRS duration). After a followup of 30 ± 20 months, 47 patients responded to CRT. Responders had a significantly longer ED and greater ratio of ED/QRS duration than nonresponders. An ED/QRS duration ≥0.38 predicted a response to CRT with 89% specificity and 53% sensitivity.