Left ventricular adaptations in herding dogs
Martins, Raimy CostaPascon, João Paulo da ExaltaçãoBéltran, Karen GuzmánMistieri, Maria Ligia de Arruda
Background: Athletes heart syndrome comprises a set of functional and anatomic cardiac changes secondary to intenseand prolonged physical exercise in humans and animals. The heart adapts to the type of activity performed, and Dopplerechocardiography is the best tool for identifying these changes. Speckle tracking echocardiography (STE) has providednew data on cardiovascular adaptations secondary to physical exercise in humans, information that conventional echocardiography cannot provide. Although physical activity and work in dogs are well documented, there are few studies oncardiovascular adaptations secondary to exercise in dogs, and no studies to date evaluated these adaptations using STE.Materials, Methods & Results: A total of 31 dogs of the Border Collie and Ovelheiro Gaúcho Brasileiro breeds weredivided into two groups: a herding group (HG, n = 15), which performed herding activity five to six times a week for atleast 4 months, and a sedentary group (SG, n = 16), with no history of physical activity in the past twelve months. Alldogs were previously subjected to electrocardiography and blood pressure measurement. After that, the animals underwentechocardiographic examination at rest at a single time point. The data were analyzed by two-way multivariate analysisof variance (ANOVA) at a level of significance of 5% (P < 0.05) and a trend at 90% (P < 0.1). The dogs of the HG hadhigher values for left-ventricular end-systolic diameter (LVESD) and systolic volume (SV), and lower values for leftventricular myocardial performance index (Tei index) and systolic septal movement. STE results indicated that the HGpresented lower values for strain and strain rate in some myocardial segments in the radial, circumferential, longitudinal,and transverse directions.Discussion: The increase in LVESD is justified by the increase in preload (volume) required to meet the increased oxygendemand... (AU)
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