Cardiology Resident University of Illinois Savoy, Illinois, United States
Abstract: Background Blood speckle imaging (BSI) enables angle-independent visualization of intracardiac blood flow particularly diastolic vortices, but its feasibility in dogs has not been established. Hypothesis/Objectives Assess the feasibility of BSI to produce left ventricular (LV) diastolic vortices in dogs. Animals Fifty client-owned dogs (25 clinically normal and 25 dogs with cardiac disease), ages 4-months-old to 14-years-old, and median body weight of 8.2 kg (range 2–44.2 kg). Methods Prospective feasibility study. Echocardiography was performed using a Vivid E95 system with 6 and 12.5 MHz probes. BSI was acquired from a zoomed apical five-chamber view with the color Doppler region encompassing the LV cavity. Frame rates of 400 - 1000 frames/s were targeted, and imaging depth and sector width were optimized to maximize temporal resolution. Color Doppler Nyquist limits of 0.41, 0.58, and 0.70 m/s were utilized. Two cardiac cycles were recorded and two acquisitions were obtained at each Nyquist limit. Feasibility was defined as visualization of one or more LV diastolic vortices. Results Forty-eight of 50 studies (96%) yielded measurable vortices. The Nyquist limit of 0.41 m/s consistently produced vortices with the largest size and longest duration. Two examinations were non-diagnostic because adequate speckle resolution could not be achieved at the imaging depths required; both dogs were large-breed. Conclusions and Clinical Importance BSI produces LV diastolic vortices in most dogs across a broad range of body sizes and cardiac conditions. Depth-related resolution may reduce feasibility in large-breed dogs. BSI may enable future noninvasive assessment of intracardiac flow in veterinary cardiology.
