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Background: Artificial intelligence (AI) could improve accuracy and reproducibility of echocardiographic measurements in dogs., Hypothesis: A neural network can be trained to measure echocardiographic left ventricular (LV) linear dimensions in dogs., Animals: Training dataset: 1398 frames from 461 canine echocardiograms from a single specialist center., Validation: 50 additional echocardiograms from the same center., Methods: Training dataset: a right parasternal 4-chamber long axis frame from each study, labeled by 1 of 18 echocardiographers, marking anterior and posterior points of the septum and free wall., Validation Dataset: End-diastolic and end-systolic frames from 50 studies, annotated twice (blindly) by 13 experts, producing 26 measurements of each site from each frame. The neural network also made these measurements. We quantified its accuracy as the deviation from the expert consensus, using the individual-expert deviation from consensus as context for acceptable variation. The deviation of the AI measurement away from the expert consensus was assessed on each individual frame and compared with the root-mean-square-variation of the individual expert opinions away from that consensus., Results: For the septum in end-diastole, individual expert opinions deviated by 0.12 cm from the consensus, while the AI deviated by 0.11 cm (P = .61). For LVD, the corresponding values were 0.20 cm for experts and 0.13 cm for AI (P = .65); for the free wall, experts 0.20 cm, AI 0.13 cm (P < .01). In end-systole, there were no differences between individual expert and AI performances., Conclusions and Clinical Importance: An artificial intelligence network can be trained to adequately measure linear LV dimensions, with performance indistinguishable from that of experts., (© 2024 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine.)

OBJECTIVE To determine effects of a combination of acepromazine maleate and butorphanol tartrate on conventional echocardiographic variables and on strain values obtained by use of 2-D speckle tracking echocardiography (STE) in healthy dogs. ANIMALS 18 healthy medium- and large-size adult dogs. PROCEDURES Transthoracic echocardiographic examination (2-D, M-mode, color flow, spectral Doppler, and tissue Doppler ultrasonography) and high-definition oscillometric blood pressure measurement were performed before and after dogs were sedated by IM administration of a combination of acepromazine (0.02 mg/kg) and butorphanol (0.2 mg/kg). Adequacy of sedation for echocardiographic examination was evaluated. Circumferential and longitudinal global and segmental strains of the left ventricle (LV) were obtained with 2-D STE by use of right parasternal short-axis and left parasternal apical views. Values before and after sedation were compared. RESULTS The sedation combination provided adequate immobilization to facilitate echocardiographic examination. Heart rate and mean and diastolic blood pressures decreased significantly after dogs were sedated. A few conventional echocardiographic variables differed significantly from baseline values after sedation, including decreased end-diastolic LV volume index, peak velocity of late diastolic transmitral flow, and late diastolic septal mitral and tricuspid annulus velocities, increased ejection time, and increased mitral ratio of peak early to late diastolic filling velocity; global strain values were not affected, but 1 segmental (apical lateral) strain value decreased significantly. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that acepromazine and butorphanol at the doses used in this study provided sedation adequate to facilitate echocardiography, with only mild influences on conventional and 2-D STE variables.

Our aim was to compare plastinated sections of the canine heart with corresponding two-dimensional (2D) echocardiographic images. Thirteen dog hearts were fixed by dilation and then processed by the S10 silicon plastination method (Biodur). Two dogs without evidence of cardiac disease were imaged using 2D echocardiography so as to obtain a complete series of the standard right and left parasternal images, which were compared with corresponding plastinated slices obtained by knife sectioning of the hearts. The plastinated slices revealed the internal anatomy of the heart with great detail and were particularly useful to display the spatial relationship between complex anatomic structures. The plastinated slices corresponded accurately with the echocardiographic images. Because of the dilation of the right heart during the fixation process, it was not possible to obtain plastinated specimens in ventricular systole. This paper may be a reference atlas for assisting 2D echocardiography interpretation.