Polish to English Medical Medical: Cardiology cardiology

This comes from a patient's echocardiography report. The parameter is given exactly as shown above. I have been unable to match the acronym with those used in echocardiography in the English language, and have no contextual words to give any further clues. The measurement before this is relates to the aortic annulus, and one after to the left atrium. Any possible help will be much appreciated.