Document Detail


Physiological relevance of quantifying segmental contraction synchrony.
MedLine Citation:
PMID:  22017611     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: Most current indices of synchrony quantify left ventricular (LV) contraction pattern in terms of a single, global (integrated) measure. We report the development and physiological relevance of a novel method to quantify LV segmental contraction synchrony.
METHODS: LV pressure-volume and echocardiographic data were collected in seven anesthetized, opened-chest dogs under several pacing modes: right atrial (RA) (control), right ventricular (RV) (dyssynchrony), and additional LV pacing at either apex (CRTa) or free wall (CRTf). Cross-correlation-based integrated (CCSI(int) ) and segmental (CCSI(seg) ) measures of synchrony were calculated from speckle-tracking derived radial strain, along with a commonly used index (maximum time delay). LV contractility was quantified using either E(es) (ESPVR slope) or ESPVR(area) (defined in the manuscript).
RESULTS: RV pacing decreased CCSI(int) at LV base (0.95 ± 0.02 [RA] vs 0.64 ± 0.14 [RV]; P < 0.05) and only CRTa improved it (0.93 ± 0.03; P < 0.05 vs RV). The CCSI(seg) analysis identified anteroseptal and septal segments as being responsible for the low CCSI(int) during RV pacing and inferior segment for poor resynchronization with CRTf. Changes in ESPVR(area) , and not in E(es) , indicated depressed LV contractility with RV pacing, an observation consistent with significantly decreased global LV performance (stroke work [SW]: 252 ± 23 [RA] vs 151 ± 24 [RV] mJ; P < 0.05). Only CRTa improved SW and contractility (SW: 240 ± 19 mJ; ESPVR(area) : 545 ± 175 mmHg•mL; both P < 0.01 vs RV). Only changes in CCSI(seg) and global LV contractility were strongly correlated (R(2) = 0.698, P = 0.005).
CONCLUSION: CCSI(seg) provided insights into the changes in LV integrated contraction pattern and a better link to global LV contractility changes. 
Authors:
Lauren Johnson; Bouchra Lamia; Hyung Kook Kim; Masaki Tanabe; John Gorcsan; David Schwartzman; Sanjeev G Shroff; Michael R Pinsky
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't     Date:  2011-10-20
Journal Detail:
Title:  Pacing and clinical electrophysiology : PACE     Volume:  35     ISSN:  1540-8159     ISO Abbreviation:  Pacing Clin Electrophysiol     Publication Date:  2012 Feb 
Date Detail:
Created Date:  2012-02-07     Completed Date:  2012-06-11     Revised Date:  2013-09-17    
Medline Journal Info:
Nlm Unique ID:  7803944     Medline TA:  Pacing Clin Electrophysiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  174-87     Citation Subset:  IM    
Copyright Information:
©2011, The Authors. Journal compilation ©2012 Wiley Periodicals, Inc.
Affiliation:
Cardiovascular Systems Laboratory, Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
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MeSH Terms
Descriptor/Qualifier:
Animals
Dogs
Echocardiography / methods*
Elasticity Imaging Techniques / methods*
Heart Ventricles / physiopathology*,  ultrasonography*
Image Interpretation, Computer-Assisted / methods*
Reproducibility of Results
Sensitivity and Specificity
Ventricular Dysfunction, Left / physiopathology*,  ultrasonography*
Grant Support
ID/Acronym/Agency:
HL04503/HL/NHLBI NIH HHS; HL067181/HL/NHLBI NIH HHS; HL073198/HL/NHLBI NIH HHS; K24 HL067181/HL/NHLBI NIH HHS; R01 HL073198/HL/NHLBI NIH HHS
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