Quantitative assessment of regional left ventricular motion after early thrombolysis using endocardial landmarks

The very existence of several methods (6, 13, 16, 20, 26, 41) to analyze left ventricular wall motion from contrast angiograms indicates that no exact, generally accepted procedure is available to track fixed points along the endocardial wall. In animals, specific sites of the endocardium can easily be followed with endocardially implanted metal clips (5, 32, 44) and roentgen cinematography. For obvious reasons, endocardial markers have not been inserted in humans, although midwall motion (9) and epicardial wall motion (3, 15, 31) have been studied in human hearts with surgically implanted metal markers. However, major differences exist in extent and direction of movements of neighboring endocardial, midwall and epicardial sites as the wall thickens (44, 64). Therefore, none of these methods can provide an accurate description of endocardial wall motion. Recently, we described and evaluated a method to assess left ventricular endocardial wall motion in humans from the pathways of anatomic landmarks recognizable on the endocardial border. For delineation of the endocardial border in the contrast angiogram, an automated high resolution outlining system (60) was employed. In the detected left ventricular contour, small landmarks are available that can be followed throughout the cardiac cycle by analysis of consecutive frames of the cineangiogram. The hypothesis that these landmarks represent specific anatomic sites has been validated by placing minute "harpoons" in the endocardium of piglets.