Schematic Clock Diagram to Assess Mitral Paravalvular Leak by 2D TEE

To the Editor, Real-time 3D transesophageal echocardiography (TEE) has proven invaluable for diagnosing and assessing paravalvular leaks (PVL) following valve replacements/repair. However, it has some limitations, which include artifacts of acoustic shadowing and reverberations, tissue dropout, reduced temporal and spatial resolution, and time constraint in the intraoperative period.[1] The unavailability of 3D TEE probes is not uncommon and, in those instances, 2D TEE is vital. During real-time 3D imaging of the prosthetic mitral valve, the location of PVL has been defined in relation to the aortic valve and left atrial appendage (LAA). In the “surgeon’s view” or “en face view,” the aortic valve is located anteriorly at the 12 O’ clock position, the interatrial septum medially at the 3 O’ clock position, and the left atrial appendage laterally at the 9 O’ clock position.[1] [Figure 1a].Figure 1: (a) Schematic surgeon’s view of the mitral valve prosthesis. LAA-Left atrial appendage. (b) Transgastric basal short axis view and its transection by the midesophageal views. (c) Schematic clock diagram in the transgastric basal short axis view. LAA-Left atrial appendageMahjoub et al.[2] proposed anatomic localization of PVL in 2D TEE, based on the polar coordinate system of a surgeon’s view time clock. According to their convention, the LAA is located at 9 O’ clock position as it can be easily identified while looking through the left atrium. Inspection of the prosthetic ring and localization of PVL is performed using cues obtained from 2D longitudinal TEE views. For example, in the midesophageal 4-chamber view at 0°, the medial or left side of the screen corresponds to 12 O’ clock on the surgeon’s view, and the lateral or right side on the screen corresponds to 6 O’ clock on the surgeon’s view [Video 1]. In 2-chamber view at 90°, the left side of the screen corresponds to 3 O’ clock, whereas the right side adjacent to the LAA corresponds to 9 O’ clock on the surgeon’s view [Video 2]. In the 150° view, the aortic valve corresponds to 11 O’ clock, whereas a defect visible on the left side of the display, opposite to the aortic valve, would correspond to 5 O’ clock on the surgeon’s view.[2] {"href":"Single Video Player","role":"media-player-id","content-type":"play-in-place","position":"float","orientation":"portrait","label":"Video 1.","caption":"","object-id":[{"pub-id-type":"doi","id":""},{"pub-id-type":"other","content-type":"media-stream-id","id":"1_aqrt5v1q"},{"pub-id-type":"other","content-type":"media-source","id":"Kaltura"}]} {"href":"Single Video Player","role":"media-player-id","content-type":"play-in-place","position":"float","orientation":"portrait","label":"Video 2.","caption":"","object-id":[{"pub-id-type":"doi","id":""},{"pub-id-type":"other","content-type":"media-stream-id","id":"1_rdcsogr9"},{"pub-id-type":"other","content-type":"media-source","id":"Kaltura"}]} To the best of our knowledge transgastric basal short axis view has not been described to locate PVL by schematic clock diagram. Therefore, to further enhance the accuracy of 2D TEE for detecting PVL we propose a schematic clock diagram in the transgastric basal short axis view. As shown in Figure 1b, compared to the 3D mitral valve en face view, the clock is oriented slightly in the counterclockwise direction.[3] In this view, the upper left side of the screen corresponds to 12 O’ clock of the surgeon’s view whereas the lower right side of the screen corresponds to 6 O’ clock of the surgeon’s view [Figure 1c and Video 3]. {"href":"Single Video Player","role":"media-player-id","content-type":"play-in-place","position":"float","orientation":"portrait","label":"Video 3.","caption":"","object-id":[{"pub-id-type":"doi","id":""},{"pub-id-type":"other","content-type":"media-stream-id","id":"1_y8rqbhjz"},{"pub-id-type":"other","content-type":"media-source","id":"Kaltura"}]} Therefore, in situations where 3D TEE is not available or there is a lack of experience in 3D TEE, the precise location of PVL can be conducted using the 2D transgastric basal short axis view in addition to 2D midesophageal longitudinal views; as the transgastric basal short axis view supplements other clock positions. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.