The role of isolated cardiac muscle preparations in the study of training effects of the heart.
D000818:Animals; D009129:Muscle Tonus; D009200:Myocardial Contraction; D009213:Myography; D010210:Papillary Muscles / Q000502:physiology; D010805:Physical Conditioning, Animal; D005082:Physical Exertion; D051381:Rats