Quantitative M-mode and two-dimensional echocardiography in calves.

A standardised echocardiographic protocol was applied to 18 healthy calves for the estimation of 51 anatomical and functional cardiac variables. These variables were measured in a long axis and a short axis view of the heart, and both two-dimensional and cursor-directed time-motion (M-) modes were used. The repeatability of each of the measurements was estimated by comparing values obtained twice within 24 hours, and most of the 51 variables showed a high degree of repeatability. Statistical analysis revealed a close correlation between cardiac measurements taken post mortem and by in vivo echocardiography, and between the echocardiographic values obtained in different scanning planes of the heart or ultrasonic modes, indicating that quantitative echocardiography is a reliable technique in calves.