Noninvasive pulsed doppler determination of cardiac output in an unanesthetized neotenic salamander, Ambystoma tigrinum

A pulsed Doppler was used to determine cardiac output noninvasively in partially restrained unanesthetized neotenic tiger salamanders, Ambystoma tigrinum (mean wt. 105.0 gm ± 13.7 SD, N = 5). Although mean heart rates were similar, mean stroke volume (0.18 ml ± 0.06) and cardiac output (11.0 ml · min−1 ± 3.6) were greater than those previously reported for other amphibia. This dissimilarity is most likely due to species differences and/or the effects of anesthesia and surgical disruption of the thoracic cavity.