title: Relationships between body dimensions, body weight, age, gender, breed and echocardiographic dimensions in young endurance horses.
abstract: BACKGROUND
  The heart's physiological adaptation to aerobic training leads to an increase in heart chamber size, and is referred to as the Athlete's heart. However, heart dimensions are also related to body weight (BWT), body size, growth and (in some species) breed. There are few published data on the relationships between heart dimensions and growth or aerobic training in Arabian and Arabian-related endurance horses. Therefore the objective of the present study was to describe the influence of body dimensions (body length (BL), thoracic circumference (TC), withers height (WH)), BWT, age, gender, breed (purebred Arabians, part-bred Arabians, Anglo-Arabians, and Others) and the initiation of endurance training on echocardiographic measurements in competition-fit endurance horses aged 4 to 6 years.
  
  
  RESULTS
  Most left atrial (LA) and left ventricular (LV) dimensions increased with age, whereas LA and LV functional indices did not. Although there was no gender difference for LV dimensions, females had larger LA dimensions. In terms of breed, Anglo-Arabians had the largest LV dimensions. Regression models indicated that the included explanatory factors had a weak influence on heart dimensions. Age, body dimensions, breed and gender showed the most consistent influence on LA dimensions, whereas BWT, breed and kilometres covered in competition showed the most consistent influence on LV dimensions.
  
  
  CONCLUSIONS
  The increase in echocardiographic dimensions with age indicates on-going growth in our population of 4 to 6 year-old horses. We also observed small changes associated with the initiation of endurance training. Morphometric dimensions had a greater influence on LA dimensions, whereas LV dimensions were also influenced (albeit weakly) by parameters associated with exercise intensity. These results may therefore reflect early adaptations linked to the initiation of endurance training.
authors.affiliation: CIRALE-Hippolia, Médecine Sportive, RD 674, F-14430, Goustranville, France. dagmart@sund.ku.dk.|Université Paris-Est, Ecole Nationale Vétérinaire d'Alfort, 7 avenue du Général de Gaulle, F-94704, Maisons-Alfort, France. dagmart@sund.ku.dk.
authors.forename: D S
authors.initials: DS
authors.lastname: Trachsel
authors.affiliation: Université Paris-Est, Ecole Nationale Vétérinaire d'Alfort, 7 avenue du Général de Gaulle, F-94704, Maisons-Alfort, France.
authors.forename: A
authors.initials: A
authors.lastname: Giraudet
authors.affiliation: Université Paris-Est, Ecole Nationale Vétérinaire d'Alfort, 7 avenue du Général de Gaulle, F-94704, Maisons-Alfort, France.
authors.forename: D
authors.initials: D
authors.lastname: Maso
authors.affiliation: Université Paris-Est, Ecole Nationale Vétérinaire d'Alfort, 7 avenue du Général de Gaulle, F-94704, Maisons-Alfort, France.
authors.forename: G
authors.initials: G
authors.lastname: Hervé
authors.affiliation: Office Fédéral de la Statistique, Espace de l'Europe 10, CH-2010, Neuchâtel, Switzerland.
authors.forename: D D
authors.initials: DD
authors.lastname: Hauri
authors.affiliation: INRA, GABI-UMR1313, 78350, Jouy-en-Josas, France.
authors.forename: E
authors.initials: E
authors.lastname: Barrey
authors.affiliation: Université Paris-Est, Ecole Nationale Vétérinaire d'Alfort, 7 avenue du Général de Gaulle, F-94704, Maisons-Alfort, France.|INRA, GABI-UMR1313, 78350, Jouy-en-Josas, France.
authors.forename: C
authors.initials: C
authors.lastname: Robert
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D001823:Body Composition / Q000502:physiology*; D004452:Echocardiography / Q000662:veterinary*; D005260:Female; D006321:Heart / Q000033:anatomy & histology*; D006736:Horses / Q000502:physiology*; D008297:Male; D010807:Physical Endurance / Q000502:physiology*; D013177:Sports
keywords: (3-10): equine; Age; Body dimensions; Body weight; Breed; Cardiovascular; Echocardiography; Endurance; Gender; Non-invasive cardiac assessment