title: Letter: A simple non-invasive technique for measuring cardiac contractility.
mesh_terms: D000818:Animals; D004285:Dogs; D004562:Electrocardiography / Q000379:methods*; D006321:Heart / Q000502:physiology*; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007263:Infusions, Parenteral; D007545:Isoproterenol / Q000008:administration & dosage / Q000494:pharmacology; D011187:Posture; D013431:Sulfates / Q000008:administration & dosage / Q000494:pharmacology; D013997:Time Factors
chemical_list: D013431:Sulfates; D007545:Isoproterenol