METHOD, FEASIBILITY, AND REPRODUCIBILITY OF HIGH FREQUENCY ECHOCARDIOGRAPHIC IMAGING IN RATS.

B. A. Anderson*. L. Brown, C. A. Hegerty. J. L. Fawcett, B. J. Shearer, and D. J. Burstow. Echocardiographic Laboratory, The Prince Charles Hospital, Brisbane, Qld.

The feasibility of performing echocardiograms on rats for the ongoing investigation of the cardiovascular changes with hypertension was determined utilising the latest "state-of-the-art" ultrasound equipment with high frequency transducers. The reproducibility and accuracy of quantitative cardiac measurements was also assessed

Method: A total of 195 echocardiographic examinations were performed in 98 male Wistar rats (0 weeks to 24 months old) over a 6 month period. Left parasternal and left apical echocardiographic images were obtained using the Hewlett Packard Sonos 5500 (12 MHz frequency transducer) at an image depth of 3 cm using two focal zones. Left ventricular M-mode measurements at the level of the papillary muscles including left ventricular end-diastolic dimension (LVEDD), left ventricular end-systolic dimension (LVESD), interventricular septum (IVS), posterior wall (PW), and fractional shortening (FS%) were obtainable in the majority of rats. Pulsed-wave Doppler velocities of the ascending aorta (AscAo), descending aorta (DescAo), mitral valve inflow (MV), and pulmonary veins (PV) were attempted in all rats.

Results: Feasibility (parameters successfully measured 1 total) is presented.

Conclusion: Echocardiographic assessment of ventricular dimensions and function is technically feasible in most adult Wistar rats. Pulsed-wave Doppler profiles are less reliably obtained. The principle limiting factor affecting the measurement of M-mode dimensions was heart rate over 400 bpm. The limiting factors for mitral inflow profiles include the size and age of the rat, heart rate, and the sample volume size.

[ Back to 47th ASM Abstract Index ]