Location of flow axis line in the left ventricle and its interaction with local myocardial motion.

Background: The interaction between local myocardial motion and blood flow dynamics should be assessed to evaluate left ventricular pump function.

Methods: The contour map of the absolute value of blood flow velocity in the left ventricle (LV) was drawn. The ridgeline of the contour was defined as the "flow axis line". LV wall motion was assessed by the tracing endocardial border in consecutive B-mode images and by myocardial tissue velocity distribution obtained by the optical flow method.

Results: The location of the main flow axis line was affected by the local myocardial movement in the short axis direction. The flow axis line method is superior to the previous investigations on two-dimensional blood flow analysis because it considered three-dimensional blood flow.

Conclusions: The flow axis line represents not only intracardiac blood flow structure but also its interaction with the cardiac wall motion.