Supplementary Videos and Figures

Supplementary Videos and Figures

Files in this Data Supplement:

• Figure 1 - A schematic guide for understanding the direction of movement of speckles in the inner and outer regions of left ventricle (LV) as shown in Video 1. As the 10-MHz ultrasound transducer is moved over the explanted heart from the apex toward the base, a clockwise movement is seen in the subepicardial region and a counter-clockwise movement is seen in the inner subendocardial region.
• Figure 2 - Longitudinal isovolumic deformation of the left ventricular (LV) wall seen on ultrasonographic speckle tracking (2-dimensional strain) (Video 5). Onset of contraction (red color, A) occurs near the apical segment and is followed by transient lengthening (blue color, B). Shortening (red color, C) reappears during ejection and travels in apex-to-base direction (D). This biphasic phenomenon has been suggested to represent a summation of initial shortening and subsequent stretching as the shape of the LV wall changes during the isovolumic contraction period (50). LA = left atrium.
• Figure 3 - Longitudinal movement of the left ventricular wall seen on tissue Doppler imaging. Velocity tracings obtained from the basal segment of the anterior wall (A) in apical 2-chamber view shows presence of distinct waves for each phase of the cardiac cycle. Transient biphasic movements are seen during the isovolumic periods (arrows, A) which also produce distinct notches in the regional displacement curves (arrows, B). A’ = late diastole; E’ = early diastole; IVC = isovolumic contraction; IVR = isovolumic relaxation; S = ejection.
• Figure 4 - Left ventricular rotation measured by 2-dimensional (2-D) speckle tracking of B-mode ultrasound images (2-D strain) in basal and apical short-axis views of the left ventricle. As seen from apex, clockwise rotation is shown in negative (degrees), whereas counterclockwise rotation is shown in positive. Net twist angle of the left ventricle has been computed as a difference of rotation measured from the basal and apical short-axis views of the left ventricle. Note that net ventricular twist during the ejection phase is positive because of higher counterclockwise rotation of the apex. Both apex and base show reversal of the direction of rotation during the phase of isovolumic relaxation. Transient untwisting is also seen during isovolumic contraction period. Phases 1 to 5 are described in Fig. 6 legend. ECG = electrocardiogram.
• Video 1 - High-resolution short-axis view of an explanted porcine left ventricle. A linear ultrasonographic transducer (10 MHz) is moved at a constant speed over the heart specimen from the apical end to the basal end for obtaining a panning view of the left ventricle in its short axis as viewed from the left ventricular base. The counter-directional arrangement of fiber-sheets in the inner and outer layers of the left ventricular wall produces an illusion of motion in counter-clockwise and clockwise directions, respectively. Supplementary Figure 1 provides a schematic guide for the direction of movement in the inner and outer layers of left ventricular wall (Source: Sengupta PP, Young Investigator Award session, Annual Scientific Sessions of the American Society of Echocardiography, San Diego, 2004).
• Video 2 - Real time epicardial imaging of a beating porcine heart in its short axis using a high resolution linear ultrasonographic transducer (14 MHz). Note the helical arrangement of the myocardial wall, as viewed from left ventricular apex, coincides with the direction of counterclockwise twist seen near the apex.
• Video 3 - The direction of longitudinal shortening deciphered by ultrasonographic speckle tracking (2-dimensional strain) in a porcine left ventricle beating in situ (apical 2-chamber view). A longitudinal region of interest has been placed along the subendocardial region of the anterior wall. Longitudinal shortening of the anterior wall (shades of red) originate in the apical segment and propagate longitudinally from the apex toward the base. Note that the onset of shortening (red) in the apical segment is followed by transient lengthening (blue) before shortening again during ejection. This biphasic movement of the left ventricular wall occurs during the isovolumic contraction phase and has been further clarified in supplementary Figure 2.
• Video 4 - Imaging of endocardial trabeculae near apex using a high resolution linear ultrasonographic transducer (14 MHz). The echocardiographic appearance of the trabeculae, as viewed from left ventricular apex, has an arrangement inverse to that of the subepicardial layer (Video 2). During systole, shearing of myocardial layers causes the subendocardial layers to buckle inward toward the left ventricular cavity.
• Video 5 - Left ventricular flow sequence on contrast echocardiography in a beating porcine heart. Contrast agent (Definity; Bristol-Myers Squibb Medical Imaging, Inc., North Billerica, Massachusetts) is injected intravenously as a slow infusion at 0.01 ml/s. B-mode images of intraventricular flow were obtained at a mechanical index of 0.2, using the apical long-axis view at 250 frames/s. Phases of cardiac cycle are identified from the movement of the mitral and aortic valves. Note the apex-to-base redirection of flow during preejection period with a vortex formed across the edge of a closing mitral valve. Isovolumic relaxation is characterized with brisk base-to-apex reversal of blood flow. Intracavitary vortex formations are also seen during early diastolic and late diastolic filling phases. Ao = aorta; LA = left atrium; LV = left ventricle; LVOT = left ventricular outflow tract.
• Video 6 - Left ventricular intracavitary flow during preejection period. The movement of contrast bubbles (left) has been tracked with particle imaging velocimetry (right) in the apical long-axis view. Note that the apex-to-base redirection of blood flow merges with a vortex formed across the edge of a closing anterior mitral leaflet. The apex-to-base movement of intracavitary flow continues further during isovolumic contraction. Ao = aorta; LA = left atrium; LV = left ventricular. Reproduced from Sengupta et al. (61).