title: High-Intensity Training Improves Global and Segmental Strains in Severe Congestive Heart Failure.
abstract: BACKGROUND
  High-intensity training (HIT) is superior to moderate aerobic training (MAT) for improving quality of life in congestive heart failure (CHF) patients. Speckle-tracking echocardiography (STE) has recently been suggested for estimation of left ventricle global and regional function. We evaluated the utility of STE for characterizing differences in cardiac function following MAT or HIT in a CHF rat model.
  
  
  RESULTS
  After baseline physiologic assessment, CHF was induced by means of coronary artery ligation in Sprague-Dawley rats. Repeated measurements confirmed the presence of CHF (ejection fraction 52 ± 10%, global circumferential strain (GCS) 10.5 ± 4, and maximal oxygen uptake (V˙O2max) 71 ± 11 mL⋅min-1⋅kg-1; P < .001 vs baseline for all). Subsequently, rats were divided into training protocols: sedentary (SED), MAT, or HIT. After the training period, rats underwent the same measurements and were killed. Training intensity improved V˙O2max(73 ± 13 mL⋅min-1⋅kg-1in MAT [P < .01 vs baseline] and 82 ± 6 mL⋅min-1⋅kg-1in HIT [P < .05 vs baseline or SED] and ejection fraction (50 ± 21% in MAT [P < .001 vs baseline] and 66 ± 7% in HIT [P > .05 vs baseline]). In addition, strains of specific segments adjacent to the infarct zone regained basal values (P > .05 vs baseline), whereas global cardiac functional parameters as assessed with the use of 2-dimensional echocardiography did not improve.
  
  
  CONCLUSIONS
  High-intensity exercise training improved function in myocardial segments remote from the scar, which resulted in compensatory cardiac remodeling. This effect is prominent, yet it could be detected only with the use of STE.
authors.affiliation: Eliachar Research Laboratory, Galilee Medical Center, Nahariya, Israel; Faculty of Medicine in the Galilee, Bar-Ilan University, Safed, Israel.
authors.forename: Yair
authors.initials: Y
authors.lastname: Blumberg
authors.affiliation: Eliachar Research Laboratory, Galilee Medical Center, Nahariya, Israel. Electronic address: offirE@gmc.gov.il.
authors.forename: Offir
authors.initials: O
authors.lastname: Ertracht
authors.affiliation: Faculty of Medicine in the Galilee, Bar-Ilan University, Safed, Israel.
authors.forename: Itai
authors.initials: I
authors.lastname: Gershon
authors.affiliation: Migal, Computational Sciences and Bioinformatics Center, Tel-Hai, Israel.
authors.forename: Noa
authors.initials: N
authors.lastname: Bachner-Hinenzon
authors.affiliation: Eliachar Research Laboratory, Galilee Medical Center, Nahariya, Israel.
authors.forename: Tali
authors.initials: T
authors.lastname: Reuveni
authors.affiliation: Faculty of Medicine in the Galilee, Bar-Ilan University, Safed, Israel; Department of Cardiology, Galilee Medical Center, Nahariya, Israel.
authors.forename: Shaul
authors.initials: S
authors.lastname: Atar
mesh_terms: D000818:Animals; D006333:Heart Failure / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D010805:Physical Conditioning, Animal / Q000379:methods / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012420:Running / Q000502:physiology*; D012720:Severity of Illness Index
keywords: Heart failure (HF); high intensity training (HIT); speckle tracking echocardiography (STE)