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Dyssynchrony, contraction efficiency and regional function with apical and non-apical RV pacing
Background: Recent work has shown no difference in change of LVEF between RV apical (RVA) pacing and non-RVA pacing in patients with normal LV function. We hypothesised that a more sensitive marker (global longitudinal strain, GLS) could identify a detrimental effect of RVA and that assessment of deformation could identify whether dyssynchrony, contraction inefficiency and regional LV impairment were responsible for functional changes.
Methods: In this substudy of Protect-PACE (The Protection of Left Ventricular Function During Right Ventricular Pacing. Does Right Ventricular High-septal Pacing Improve Outcome Compared With Right Ventricular Apical Pacing?), a randomised controlled trial of RVA and non-RVA pacing in pacemaker-dependent patients with preserved EF, 145 patients (76 with RVA) with echocardiograms of sufficient quality underwent measurement of LV longitudinal strain (GLS) from speckle tracking just after implantation and at 2 years. LV dyssynchrony, discoordination and regional apical longitudinal strain were also measured.
Results: Pacing was associated with reduced GLS after 2 years, although 2-year GLS was lower in RVA (-13.9 ± 4.1 vs -15.5 ± 4.6, p = 0.02). RVA was an independent correlate of ΔGLS, although there was a minor difference in ΔGLS between the RVA and non-RVA groups (-1.8 ± 3.6 vs -0.8 ± 3.4%, p = 0.07), reflecting impairment of GLS at baseline in RVA. Apical strain was significantly lower in RVA than those in non-RVA at baseline and 2 years (both p < 0.01). Dyssynchrony and discoordination parameters at 2 years also showed significant deterioration in RVA. Apical strain, dyssynchrony and discoordination parameters at 2 years were significantly associated with ΔGLS.
Conclusions: Inefficient dyssynchronous contraction and the decrease in apical strain appear to be associated with global LV impairment in RVA.
History
Publication title
HeartVolume
101Issue
8Pagination
600-608ISSN
1355-6037Department/School
Menzies Institute for Medical ResearchPublisher
BMJ Publishing GroupPlace of publication
British Med Assoc House, Tavistock Square, London, England, Wc1H 9JrRights statement
Copyright 2015 Copyright Article author (or their employer)Repository Status
- Restricted