The present embodiments relate generally to systems, methods, and apparatus for determining a heart rate of an imaged heart in an ultrasound image feed. A plurality of ultrasound images can first be acquired. For each ultrasound image of the plurality of ultrasound images, the image can be divided into a plurality of regions； where each region is positioned so that the region corresponds to a substantially similar region location present across the plurality of ultrasound images. For each region location on each of the plurality of ultrasound images, a statistical calculation on image data of the region location can be performed. For each region location, a frequency of change in the statistical calculation over the plurality of ultrasound images can then be determined. The region location having a dominant determined frequency of change in the statistical calculation (over the plurality of ultrasound images) can be identified as a region of interest (ROI). The heart rate can be calculated based on the determined frequency of change of the ROI.
