title: Two-dimensional echocardiography with a 15-MHz transducer is a promising alternative for in vivo measurement of left ventricular mass in mice.
abstract: Murine models of left ventricular (LV) hypertrophy recently have been developed. We tested the accuracy of 2-dimensional (2D) echocardiographic measurement of LV mass with high-frequency imaging in mice. Ten anesthetized mice (weight 20 to 31 g, aged 1 to 5 months) were examined with a 15-MHz transthoracic linear-array transducer. End-diastolic myocardial area (A)(epicardial - endocardial) from the parasternal short-axis view at the midpapillary level and LV length (L) from the parasternal long-axis view were measured to calculate LV mass with the area-length method (1.05 [5/6 x A x L]) and data were compared with LV-mass with the 2D guided M-mode method. Within 3 days of echocardiography, the hearts were removed and weighed after potassium-induced cardiac arrest. Two-dimensional echocardiographic measurement with a 15-MHz transducer was performed in all mice. LV chamber dimensions included end-diastolic septal (0.80 +/- 0.12 mm) and posterior wall thickness (0.76 +/- 0.13 mm), end-diastolic dimension (3.64 +/- 0.28 mm), and end-systolic dimension (2.34 +/- 0.32 mm). Echocardiographic LV mass with the area-length method, 2D guided M-mode method, and autopsy LV weight were 80.8 +/- 16.1 mg, 97.6 +/- 17.8 mg, and 78.8 +/- 13.2 mg, respectively. A strong correlation existed between LV weight (x ) and echocardiographic LV mass (y ) with the area-length method: y = 0.745x + 18.9, r =0.908, standard error of estimate (SEE) = 5.9 mg, P <.0005. This correlation was stronger than that of LV weight (x ) and echocardiographic LV mass (y ) with the 2D guided M-mode method: y = 0.577x + 22.6, r =0.779, SEE = 8.8 mg, P =.008. These data suggest that serial in vivo measurements of LV mass with the 2D area-length method may be more accurate than M-mode methods in experimental murine models of LV pathology.
authors.affiliation: Adult Echocardiographic Laboratory, Cardiovascular Research Institute, University of California, San Francisco, 94143-0214, USA.
authors.forename: H J
authors.initials: HJ
authors.lastname: Youn
authors.forename: G
authors.initials: G
authors.lastname: Rokosh
authors.forename: S J
authors.initials: SJ
authors.lastname: Lester
authors.forename: P
authors.initials: P
authors.lastname: Simpson
authors.forename: N B
authors.initials: NB
authors.lastname: Schiller
authors.forename: E
authors.initials: E
authors.lastname: Foster
mesh_terms: D000818:Animals; D003971:Diastole; D004195:Disease Models, Animal; D004452:Echocardiography / Q000295:instrumentation / Q000379:methods*; D004699:Endocardium / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D005240:Feasibility Studies; D006346:Heart Septum / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D006352:Heart Ventricles / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D017379:Hypertrophy, Left Ventricular / Q000000981:diagnostic imaging; D007091:Image Processing, Computer-Assisted / Q000379:methods; D016014:Linear Models; D051379:Mice; D015588:Observer Variation; D009929:Organ Size; D010210:Papillary Muscles / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D010496:Pericardium / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D015203:Reproducibility of Results; D013599:Systole; D014159:Transducers