title: Reproducibility and feasibility of right ventricular strain and strain rate (SR) as determined by myocardial speckle tracking during high-intensity upright exercise: a comparison with tissue Doppler-derived strain and SR in healthy human hearts.
abstract: This study aimed to establish feasibility for myocardial speckle tracking (MST) and intra-observer reliability of both MST and tissue velocity imaging (TVI)-derived right ventricular (RV) strain (ϵ) and strain rate (SR) at rest and during upright incremental exercise. RV ϵ and SR were derived using both techniques in 19 healthy male participants. MST-derived ϵ and SR were feasible at rest (85% of segments tracked appropriately). Feasibility reduced significantly with progressive exercise intensity (3% of segments tracking appropriately at 90% maximum heart rate (HRmax)). Coefficient of variations (CoVs) of global ϵ values at rest was acceptable for both TVI and MST (7-12%), with low bias and narrow limits of agreement. Global SR data were less reliable for MST compared with TVI as demonstrated with CoV data (systolic SR=15 and 61%, early diastolic SR=16 and 17% and late diastolic SR=26 and 31% respectively). CoVs of global RV ϵ and SR obtained at 50% HRmax were acceptable using both techniques. As exercise intensity increased to 70 and 90% HRmax, reliability of ϵ and SR values reduced with larger variability in MST. We conclude that RV global and regional ϵ and SR data are feasible, comparable and reliable at rest and at 50% HRmax using both MST and TVI. Reliability was reduced during higher exercise intensities with only TVI acceptable for clinical and scientific use.
authors.affiliation: Research Institute for Sport and Exercise Sciences, Liverpool John Moores University , Tom Reilly Building, Byrom Street, Liverpool, L3 3AF , UK.
authors.forename: Rachel N
authors.initials: RN
authors.lastname: Lord
authors.affiliation: Research Institute for Sport and Exercise Sciences, Liverpool John Moores University , Tom Reilly Building, Byrom Street, Liverpool, L3 3AF , UK.
authors.forename: Keith
authors.initials: K
authors.lastname: George
authors.affiliation: Research Institute for Sport and Exercise Sciences, Liverpool John Moores University , Tom Reilly Building, Byrom Street, Liverpool, L3 3AF , UK.
authors.forename: Helen
authors.initials: H
authors.lastname: Jones
authors.affiliation: Research Institute for Sport and Exercise Sciences, Liverpool John Moores University , Tom Reilly Building, Byrom Street, Liverpool, L3 3AF , UK ; Countess of Chester Hospital, NHS Trust , Chester , UK.
authors.forename: John
authors.initials: J
authors.lastname: Somauroo
authors.affiliation: Research Institute for Sport and Exercise Sciences, Liverpool John Moores University , Tom Reilly Building, Byrom Street, Liverpool, L3 3AF , UK.
authors.forename: David
authors.initials: D
authors.lastname: Oxborough
keywords: exercise echocardiography; right ventricle; strain rate imaging; tissue Doppler and strain echocardiography