Final Feigenbaum’s Echocardiography DIGITAL

Chapter 5 Evaluation of Systolic Function of the Left Ventricle

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Chapter 5 Evaluation of Systolic Function of the Left Ventricle

Evaluation of Systolic Function of the Left Ventricle

FIGURE 5.9. Apical four-chamber view recorded in a young patient with normal ventricular function and fairly prominent trabeculae along the lateral ventricular wall. The upper panel is an apical four-chamber view in which the papillary muscle and trabeculae can be seen on the lateral wall ( arrows ). The lower left panel is the initial, unaltered, automatically deter- mined endocardial border from a commercially available platform. Note that the algorithm for identifying the endocardial border has included papillary muscles and the trabeculae within the ventricular cavity which results in a calculated left ventricular volume of 99 mL. The lower right panel was recorded after manual adjustment of the previously automatically determined border. Only the lateral border has required adjustment. After adjustment, notice that the calculated left ventricular volume is 158 mL.

FIGURE 5.8. Apical four-chamber view recorded in a patient with normal ventricular size and function. The upper panel is the apical four-chamber view from which volume can be calculated. Notice the vague echoes at the apical septal and apical lateral wall due to a combination of beam width imaging and trabeculae ( arrows ) as well as the papillary muscle protruding into the left ventricular cavity ( arrow ). The lower panel outlines three separate contours which could be drawn from this view. The white line represents the true inner endo- cardial border of the left ventricle, excluding trabeculation, beam width imaging, and the papillary muscle from the cavity, and results in a left ventricle cavity volume of 97 mL. The yellow line excludes the papillary muscle tip but includes the apical trabeculations and tan- gential beam–related echoes and results in a left ventricular volume of 70 mL. The red line further excludes the papillary muscle tip from the left ventricular volume and would result in a left ventricular volume of 60 mL. the endocardial boundary. A er the initial approximation of the endocardial boundary, operator interaction is o en required to adjust the boundary to t the visually identi ed cavity (Fig. 5.11). Because the algorithms are detecting a blood pool–tissue boundary they o en delineate the cavity of the le ventricle along the boundary of trabeculations and papillary muscles, which by convention should be excluded from the blood pool for calculation of ventricular vol- umes (Fig. 5.9). €ese same techniques (or speckle tracking which is discussed subsequently), for detecting the cavity boundary can also be applied to three dimensional datasets (Fig. 5.12). A er the endocardial boundary has been identi ed, various algorithms are utilized to determine the volume. In earlier systems, Simpson rule was employed in a manner similar to that used for manually drawn contours. In its simplest form borders were out- lined only in diastole and end-systole. Modern systems typically determine the le ventricular volume from an actual pixel count bounded by the endocardial boundary. Ventricular volume can then

FIGURE 5.10. Apical four-chamber view from which continuous volume determination has been made using an automated acoustic boundary detection system. The apical four- chamber view is presented. The dots represent the automatically determined acoustic boundary after manual adjustment. See Figure 5.11 for the initially automatically detected acoustic boundary. At the upper right is a table with numeric values. Note the calculated ejection fraction of 58.1%.

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