Link to the University of Pittsburgh Homepage
Link to the University Library System Homepage Link to the Contact Us Form

Differential effects of left ventricular pacing sites in an acute canine model of contraction dyssynchrony

Johnson, L and Hyung, KK and Tanabe, M and Gorcsan, J and Schwartzman, D and Shroff, SG and Pinsky, MR (2007) Differential effects of left ventricular pacing sites in an acute canine model of contraction dyssynchrony. American Journal of Physiology - Heart and Circulatory Physiology, 293 (5). ISSN 0363-6135

[img] Plain Text (licence)
Available under License : See the attached license file.

Download (1kB)

Abstract

The goal of the present study was to assess the effects of left ventricular (LV) pacing sites (apex vs. free wall) on radial synchrony and global LV performance in a canine model of contraction dyssynchrony. Ultrasound tissue Doppler imaging and hemodynamic (LV pressure-volume) data were collected in seven anesthetized, opened-chest dogs. Right atrial (RA) pacing served as the control, and contraction dyssynchrony was created by simultaneous RA and right ventricular (RV) pacing to induce a left bundle-branch block-like contraction pattern. Cardiac resynchronization therapy (CRT) was implemented by adding simultaneous LV pacing to the RV pacing mode at either the LV apex (CRTa) or free wall (CRTf). A new index of synchrony was developed via pair-wise cross-correlation analysis of tissue Doppler radial strain from six midmyocardial cross-sectional regions, with a value of 15 indicating perfect synchrony. Compared with RA pacing, RV pacing significantly decreased radial synchrony (11.1 ± 0.8 vs. 4.8 ± 1.2, P < 0.01) and global LV performance (cardiac output: 2.0 ± 0.3 vs. 1.4 ± 0.1 l/min and stroke work: 137 ± 22 vs. 60 ± 14 mJ, P < 0.05). Although both CRTa and CRTf significantly improved radial synchrony, only CRTa markedly improved global function (cardiac output: 2.1 ± 0.2 l/min and stroke work: 113 ± 13 mJ, P < 0.01 vs. RV pacing). Furthermore, CRTa decreased LV end-systolic volume compared with RV pacing without any change in LV end-systolic pressure, indicating an augmented global LV contractile state. Thus, LV apical pacing appears to be a superior pacing site in the context of CRT. The dissociation between changes in synchrony and global LV performance with CRTf suggests that regional analysis from a single plane may not be sufficient to adequately characterize contraction synchrony. Copyright © 2007 the American Physiological Society.


Share

Citation/Export:
Social Networking:
Share |

Details

Item Type: Article
Status: Published
Creators/Authors:
CreatorsEmailPitt UsernameORCID
Johnson, L
Hyung, KK
Tanabe, M
Gorcsan, Jgorcsan@pitt.eduGORCSAN
Schwartzman, D
Shroff, SGsshroff@pitt.eduSSHROFF
Pinsky, MRpinsky@pitt.eduPINSKY
Date: 1 November 2007
Date Type: Publication
Journal or Publication Title: American Journal of Physiology - Heart and Circulatory Physiology
Volume: 293
Number: 5
DOI or Unique Handle: 10.1152/ajpheart.00728.2007
Schools and Programs: School of Medicine > Critical Care Medicine
Refereed: Yes
ISSN: 0363-6135
PubMed ID: 17873017
Date Deposited: 05 Mar 2012 17:27
Last Modified: 21 Jan 2019 14:55
URI: http://d-scholarship.pitt.edu/id/eprint/11191

Metrics

Monthly Views for the past 3 years

Plum Analytics

Altmetric.com


Actions (login required)

View Item View Item