This video from the Netherlands says about itself:
8 April 2016
This footage shows a heart sonogram on a Harbour porpoise. This female porpoise was found on the Dutch island of Texel and had several medical problems. She was emaciated, had problems in her intestines and had anemia. Also a heart defect was suspected and therefore help was asked from a specialist. During this heart sonogram this defect could me established. More about this article you can find here.