title: Measurement of internal left ventricular diameter by a tracking sonomicrometer.
mesh_terms: D000818:Animals; D001699:Biometry; D004285:Dogs; D004581:Electronics; D006321:Heart / Q000033:anatomy & histology*; D006352:Heart Ventricles / Q000033:anatomy & histology; D008722:Methods; D014159:Transducers; D014463:Ultrasonography