Document Detail

Comparative mechanical activation mapping of RV pacing to LBBB by 2D and 3D speckle tracking and association with response to resynchronization therapy.
MedLine Citation:
PMID:  20466341     Owner:  NLM     Status:  MEDLINE    
OBJECTIVES: The goals of this study were to compare patterns of mechanical activation in patients with chronic right ventricular (RV) pacing with those with left bundle branch block (LBBB) using 2-dimensional and novel 3-dimensional speckle tracking, and to compare ejection fraction (EF) response and long-term survival after cardiac resynchronization therapy (CRT). BACKGROUND: Several randomized CRT trials have excluded patients with chronic RV pacing, and current guidelines for CRT include patients with intrinsically widened QRS, typically LBBB. METHODS: We studied 308 patients who were referred for CRT: 227 had LBBB, 81 were RV paced. Dyssynchrony was assessed by tissue Doppler, routine pulsed Doppler, and 2-dimensional speckle-tracking radial strain. 3D strain was assessed using speckle tracking from a pyramidal dataset in a subset of 57 patients for mechanical activation mapping. Survival after CRT was compared with survival in a group of 46 patients with attempted, but failed, CRT. RESULTS: Patients with chronic RV pacing and LBBB had similar intraventricular dyssynchrony, with opposing wall delays by tissue Doppler of 82 +/- 45 ms versus 87 +/- 63 ms and anteroseptum-to-posterior delays by speckle tracking of 225 +/- 142 ms, versus 211 +/- 107 ms, respectively. RV-paced patients, however, had greater interventricular dyssynchrony: 44 +/- 24 ms versus 35 +/- 21 ms (p < 0.01), which correlated with their greater QRS duration (p < 0.001). Sites of latest mechanical activation were most often posterior or lateral in both groups, but RV-paced patients had sites of earliest activation more often from the inferior-septum and apex (p < 0.05). EF response was similar in RV-paced and LBBB groups, and survival free from transplantation or mechanical support after CRT was similarly favorable as compared with failed CRT patients over 5 years (p < 0.01). CONCLUSIONS: RV-paced patients, when compared with LBBB patients, had similar dyssynchronous patterns of mechanical activation and greater interventricular dyssynchrony. Importantly, RV-paced patients had similar EF response and long-term outcome as those with LBBB, which supports their candidacy for CRT.
Hidekazu Tanaka; Hideyuki Hara; Evan C Adelstein; David Schwartzman; Samir Saba; John Gorcsan
Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, N.I.H., Extramural    
Journal Detail:
Title:  JACC. Cardiovascular imaging     Volume:  3     ISSN:  1876-7591     ISO Abbreviation:  JACC Cardiovasc Imaging     Publication Date:  2010 May 
Date Detail:
Created Date:  2010-05-14     Completed Date:  2010-08-30     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  101467978     Medline TA:  JACC Cardiovasc Imaging     Country:  United States    
Other Details:
Languages:  eng     Pagination:  461-71     Citation Subset:  IM    
Copyright Information:
Copyright 2010 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
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MeSH Terms
Atrioventricular Block / mortality,  physiopathology,  therapy*,  ultrasonography
Bundle-Branch Block / mortality,  physiopathology,  therapy*,  ultrasonography
Cardiac Pacing, Artificial*
Disease-Free Survival
Echocardiography, Doppler*
Echocardiography, Doppler, Pulsed
Echocardiography, Three-Dimensional*
Electric Countershock*
Heart Failure / mortality,  physiopathology,  therapy*,  ultrasonography
Heart Ventricles / physiopathology,  ultrasonography
Kaplan-Meiers Estimate
Linear Models
Middle Aged
Patient Selection
Predictive Value of Tests
Stroke Volume
Time Factors
Treatment Outcome
Ventricular Function, Left*
Grant Support
2 K24 HL004503-06/HL/NHLBI NIH HHS

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