In vivo echocardiographic detection of enhanced left ventricular function in gene-targeted mice with phospholamban deficiency

BD Hoit, SF Khoury, EG Kranias, N Ball… - Circulation …, 1995 - Am Heart Assoc
BD Hoit, SF Khoury, EG Kranias, N Ball, RA Walsh
Circulation research, 1995Am Heart Assoc
We evaluated the ability of M-mode and Doppler echocardiography to assess left ventricular
(LV) function reliably and repeatedly in mice and tested whether these techniques could
detect physiological alterations in phospholamban (PLB)–deficient mice. Anesthetized wild-
type mice (n= 7) and mice deficient in PLB (n= 8) were studied with two-dimensional guided
M-mode and Doppler echocardiography using a 9-MHz imaging and 5-to 7.5-MHz Doppler
transducer. Data were acquired in the baseline state and after intraperitoneal isoproterenol …
Abstract
We evaluated the ability of M-mode and Doppler echocardiography to assess left ventricular (LV) function reliably and repeatedly in mice and tested whether these techniques could detect physiological alterations in phospholamban (PLB)–deficient mice. Anesthetized wild-type mice (n=7) and mice deficient in PLB (n=8) were studied with two-dimensional guided M-mode and Doppler echocardiography using a 9-MHz imaging and 5- to 7.5-MHz Doppler transducer. Data were acquired in the baseline state and after intraperitoneal isoproterenol administration (2.0 μg/g IP). Interobserver and intraobserver variability and reproducibility were excellent. PLB-deficient mice were associated with significant (P<.05) increases in several physiological parameters (mean±SD) compared with wild-type control mice: normalized mean velocity of circumferential shortening (7.7±2.1 versus 5.5±1.0 circ/sec), peak aortic velocity (105±13 versus 75±9.2 cm/s), mean aortic acceleration (57±16 versus 31±4 m/s2), and peak early-diastolic transmitral velocity (80.0±7.2 versus 66.9±7.7 cm/s). LV dimensions, shortening fractions, heart rates, late diastolic transmitral (A) velocities, and early to late (E/A) diastolic velocity ratios were similar in both groups. Isoproterenol administration resulted in significant increases in Doppler indices of ventricular function in control but not PLB-deficient mice. These findings indicate that assessment of LV function can be performed noninvasively in mice under varying physiological conditions and that PLB regulates basal LV function in vivo.
Am Heart Assoc