TRANSESOPHAGEAL ECHOCARDIOGRAPHY AND ACOUSTIC QUANTIFICATION IN ASSESSING REGIONAL LEFT-VENTRICULAR WALL-MOTION

Acoustic Quantification (AQ) is a technique based on analysis of ultra sonic integrated backscatter. It enables a real time detection of bloo d - tissue borders and numbers the end-diastolic and end-systolic area s throughout the cardiac cycle. AQ added to the 2D image therefore off ers an on-line estimate of global ventricular function in the operatin g room. Since Aa is dependent on a good 2D image as well as adjustment of both transmit- and time gain control the question arises whether t his leads to a different assessment, compared co che 2D image only, of off-line assessment of regional left ventricular wall motion (LVWM). Twenty-three consenting patients scheduled for elective coronary bypas s grafting were studied. A total of 31 observations were performed and divided into 21 short axis and 10 three chamber long axis views. Regi onal LVWM score was assessed off-line (video recordings postoperativel y) by two independent readers on two occasions. There was no intra-rea der difference in assessment of regional LVWM in the short axis view w hen Aa was added to the 2D image. On the other hand, the interreader d ifference was highly significant both without and with AQ (P=0.0001) i n this view. In the long axis view the intra-reader difference was sig nificant (P=0.0008 and P=0.004 respectively), while the inter-reader d ifference was non-significant. However, the overall intra-reader and i nter-reader agreement was 78% or higher except for the intra-reader di fference in the long axis view. Our conclusion is that AQ added to the 2D image does not alter LVWM score in the short axis bur in the three chamber long axis view