Two-dimensional echocardiography with a 15-MHz transducer is a promising alternative for in vivo measurement of left ventricular mass in mice

Murine models of left ventricular (LV) hypertrophy recently have been devel oped. We tested the accuracy of 2-dimensional (2D) echocardiographic measur ement 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 transt horacic Linear-array transducer. End-diastolic myocardial area (A)(epicardi al - endocardial) from the parasternal short-axis view at the midpapillary level and LV length (L) from the parasternal long-axis view were measured t o calculate LV mass with the area-length method (1.05 [5/6 X A X L]) and da ta were compared with LV-mass with the 2D guided M-mode method. Within 3 da ys 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 inclu ded 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-systo lic dimension (2.34 +/- 0.32 mm). Echocardiographic LV mass with the area-l ength 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 cor relation existed between LV weight (x) and echocardiographic LV mass (y) wi th the area-length method: y = 0.745x + 18.9, r =0.908, standard error of e stimate (SEE) = 5.9 mg, P <.0005. This correlation was stronger than that o f LV weight Cx) 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 s uggest 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 mode ls of LV pathology.