title: Physical conditioning effects on cardiac dimensions: a review of echocardiographic studies.
abstract: Echocardiographic studies related to chronic exercise effects on cardiac dimensions were reviewed. Sources of error in M-mode echocardiography include its resolving power, changes in transmission velocity in a nonhomogeneous medium, subjective analysis of records, and assumptions to predict ventricular volume and mass from one-dimensional data. Existing studies document larger values for left ventricular internal diastolic dimension (LVIDd) in endurance athletes, and for septal and posterior wall thicknesses (ST, PWT) in endurance, strength-type and anaerobic-type athletes compared to nonathletes. Values for the athletes were lower than in cardiac disease states. Short-term conditioning studies generally reported unimpressive changes in ventricular dimensions. Existing literature also does not clearly support a relationship between training intensity and the degree of cardiac enlargement, or changes in the heart's trainability with age. Hereditary and/or familial factors appear to influence heart size to some degree and a correlation with anthropometric variables may exist. Further study concerning hereditary and long-term conditioning effects is recommended.
mesh_terms: D000293:Adolescent; D000328:Adult; D000885:Anthropology, Physical; D001824:Body Constitution; D006332:Cardiomegaly / Q000175:diagnosis; D002648:Child; D002675:Child, Preschool; D004452:Echocardiography; D005190:Family; D005260:Female; D006321:Heart / Q000033:anatomy & histology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D005082:Physical Exertion; D013177:Sports; D014427:Twins