Left Ventricular Outflow Tract and Transcatheter Mitral Valve Replacement Obstruction and TMVR: Predictors, Evaluation, and Solutions

Figures

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  Figure 1. (a) Gated cardiac CTA assessment of the LVOT in long access following insertion of a hypothetical valve within the previously defined mitral annulus in a patient with previous TAVR. The total height of the valve frame is simulated by the blue outline, while the shorter, pink lines define the covered portion of the prosthesis cage. The white and blue tulips markers at the basal septum define the LVOT area plane for the (b) neo-LVOT (blue), measuring 142.7 mm2, and (c) skirt neo-LVOT (white), measuring 364.3 mm2. Abbreviations: CTA, computed tomography angiography; ES, end systole; LVOT, left ventricular outflow tract; MPR, multiplanar reformat; TAVR, transcatheter aortic valve replacement.

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  Figure 2. Displacement of a long, billowy anterior mitral valve leaflet by the cage of the transcatheter heart valve may result in dynamic LVOT obstruction, mimicking SAM type physiology. Abbreviations: LVOT, left ventricular outflow tract; SAM, systolic anterior motion.

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  Figure 3. SESAME involves traversing the interventricular septal long access with a penetrative wire, which is then snared and externalized. Electrocautery is applied to slice the muscle bulk, increasing the LVOT area by creating a “valley” for blood flow through the septum, which enlarges during healing due to tension from the circumferential fibers of cardiac muscle. Abbreviations: NHLBI, National Heart Lung and Blood Institute; SESAME, septal scoring along the midline endocardium.

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  Figure 4. LAMPOON is performed at the time of TMVR. (a) As seen in the three dimensional en face projection prior to transcatheter heart valve and the two dimensional three chamber view following implantation, (b) the anterior mitral leaflet is sliced from the base to the tip to allow for maximal splay, though nonlaminar flow is still observed as blood flows through the open cells of the valve cage. (c and d) The open position of the mitral leaflet against the valve cage can be clearly seen in CTA reconstructions and is necessary to prevent LVOT obstruction in this patient, given the small predicted neo-LVOT (61 mm2). Abbreviations: LAMPOON, laceration of the anterior mitral leaflet to prevent left ventricular outflow tract obstruction; TMVR, transcatheter mitral valve replacement.