To view the full text, please login as a subscribed user or purchase a subscription. Click here to view the full text on ScienceDirect. The normal heart is shown on the left at the beginning of the excitation (red) of the left ventricle. Electrical vectors that are projecting from the segments of the heart are color coded for each segment (anteroseptal—black, anterosuperior—green, posterior—blue, and inferior—pink). Three vectors are shown for each segment at the midpoint of the apical third, the middle third, and the basal third. On the right, the heart with medium anterior MI shows its infracted myocardium in gray. As a result of the infarct, the excitation of the anteroseptal segment is greatly diminished. On the left, we see a single summation vector at 20 milliseconds from the beginning of the QRS complex. On the right, we see the history of the vectors for the entire QRS complex. The summation vectors and the surface of the excitation (red) are shown for the normal and the heart with medium anterior MI for the first 55 milliseconds of the QRS complex. A view of a 3D vector diagram alone from the top of the heart shows the extreme modification of the normal heart by the medium anterior MI. The Q waves that result in the V1, V2, and V3 leads are obviously due to the loss of the initial anterior vectors. Medium posterior MI shows the rejection of vectors to the posterior and the deflection of initial vectors to the anterior direction. This is shown in the 12 lead by the strong R waves in leads V1 to V3. Medium inferior MI shows the large initial deflection of vectors to the superior and away from the MI in the inferior quadrant. The limb leads III, aVF, and II show deep and long Q waves. This figure shows a large anterior MI, and in the top diagram the point of obstruction by coronary thrombosis in the proximal left anterior descending artery (red circle) and the arteries with obstructed flow in blue. In the lower diagram are the areas in which the myocardial cells are infracted, in light blue for only subendocardial infarction, and in dark blue for transmural infarction. Activation diagrams of the right and left ventricles (RV, LV) during the QRS complex for LBBB. Initial activation of the RV at 25 milliseconds shows the balance of forces between the RV free wall (black vectors) and the RV septal (blue vectors) point posteriorly. At 65 milliseconds, the RV free wall is finished and the RV septum is near finished, while the main activation is the LV via the propagation of the Purkinje system and the inferior and anterosuperior myocardium. All vectors point posteriorly as shown in blue. Left bundle branch block at 65 milliseconds is apparent from the rapid posterior deflection of the total vector sum. The large negative Q waves are seen in V1 to V4. This new training method is based on developing a sound understanding of the sequence in which electrical excitation spreads through both the normal and the infarcted myocardium. The student is made aware of the cardiac electrical performance through a series of 3-dimensional pictures during the excitation process. The electrocardiogram 3D Heart 3-dimensional program contains a variety of different activation simulations. Currently, this program enables the user to view the activation simulation for all of the following pathology examples: Simulations relating to other cardiac abnormalities, such as bundle branch block and left ventricular hypertrophy fasicular block, are being developed as part of a National Institute of Health (NIH) Phase 1 Small Business Innovation Research (SBIR) program. If you are a current subscriber with Society Membership or an Account Number, claim your access now. Source.