title: Impact of high-intensity endurance exercise on regional left and right ventricular myocardial mechanics.
abstract: OBJECTIVE
  Strenuous endurance exercise acutely increases myocardial wall stress and evokes transient functional cardiac perturbations. However, it is unclear whether exercise-induced functional cardiac disturbances are ubiquitous throughout the myocardium or are segment specific. The aim of this study was to examine the influence of high-intensity endurance exercise on global and segmental left (LV) and right (RV) ventricular tissue deformation (strain).
  
  
  RESULTS
  Echocardiography was used to measure strain in 23 active men (age: 28 ± 2 years; VO2 peak: 4.5 ± 0.7 L min-1) at rest and during a standardized low-intensity exercise challenge, before and after a 90-min high-intensity endurance cycling intervention. Following the cycling intervention, LV and RV global strain decreased at rest (LV: -18.4 ± 0.4% vs. -17.7 ± 0.4%, P < 0.05; RV: -27.6 ± 0.7% vs. -26.4 ± 0.6%, P < 0.05) and by a greater extent during the low-intensity exercise challenge (LV: -21.3 ± 0.4% vs. -19.2 ± 0.5%, P < 0.01; RV: -28.4 ± 0.8% vs. -23.5 ± 0.9%, P < 0.01). Reductions in LV strain were unique to regions of RV attachment (e.g. LV septum: -24.4 ± 0.5% vs. -21.4 ± 0.6%, P < 0.01) with lateral (-18.9 ± 0.4% vs. -18.4 ± 0.5%) and posterior segments (-19.5 ± 0.4% vs. -18.8 ± 0.7%) unaffected. Similarly, augmentation of strain from rest to exercise was abolished in the RV free wall (-1.1 ± 1.0% vs. 2.9 ± 1.2%, P < 0.01), reduced in the septum (-4.6 ± 0.4% vs. -2.4 ± 0.5%, P < 0.01), and unchanged in the lateral (-1.2 ± 0.6% vs. -0.9 ± 0.6%) and posterior walls (-1.7 ± 0.6% vs. -1.3 ± 0.7%).
  
  
  CONCLUSIONS
  Changes in ventricular strain following high-intensity exercise are more profound in the right ventricle than in the left ventricle. Reductions in LV strain were unique to the septal myocardium and may reflect ventricular interactions secondary to exercise-induced RV dysfunction.
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN 55905, USA.|Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia.
authors.forename: Glenn M
authors.initials: GM
authors.lastname: Stewart
authors.affiliation: Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia.|Cardiology Division, The Prince Charles Hospital, Brisbane, Australia.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Chan
authors.affiliation: Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia.|Department of Cardiology, Fujita Health University, Nagoya, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Yamada
authors.affiliation: Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia.
authors.forename: Justin J
authors.initials: JJ
authors.lastname: Kavanagh
authors.affiliation: Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia.
authors.forename: Luke J
authors.initials: LJ
authors.lastname: Haseler
authors.affiliation: Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia.|Department of Cardiology, Fujita Health University, Nagoya, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Shiino
authors.affiliation: Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia.
authors.forename: Surendran
authors.initials: S
authors.lastname: Sabapathy
mesh_terms: D000328:Adult; D015331:Cohort Studies; D025401:Echocardiography, Stress / Q000379:methods*; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008297:Male; D010807:Physical Endurance / Q000502:physiology*; D011446:Prospective Studies; D055070:Resistance Training; D013318:Stroke Volume / Q000502:physiology; D016277:Ventricular Function, Left / Q000502:physiology*; D016278:Ventricular Function, Right / Q000502:physiology*; D020257:Ventricular Remodeling / Q000502:physiology*; D055815:Young Adult
keywords: cardiac function; endurance exercise; segmental strain; speckle-tracking echocardiography