PMC7716751_01
The preoperative echocardiogram was showing no obstruction of the left ventricular outflow tract. (a) The apical four-chamber view. (b) The apical four-chamber view with flow mapping. (c) The apical three-chamber view. (d) The apical three-chamber view with flow mapping. A normal left ventricular contraction and mild aortic regurgitation was noted on the apical three-chamber view (Supplement video 1).
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The preoperative echocardiography showed good biventricular contraction with neither regional wall motion abnormality nor LVOT obstruction (Figure 1 and Supplement video 1).
The postoperative echocardiogram performed during hemodynamic instability revealed a left ventricular outflow tract (LVOT) obstruction caused by systolic anterior movement of the mitral leaflet (SAM). (a) SAM leading to dynamic LVOT obstruction and the apical ballooning of the left ventricle. (b) A severe mitral regurgitation secondary to SAM. (c) Elevated pressure gradient across LVOT of 73 mmHg with typical dagger-shaped spectral Doppler. (d) High pressure gradient across the mitral valve in systole. The SAM and ballooning of the LV apex was seen on the apical three-chamber view (Supplement video 2).
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A senior cardiologist was called upon to perform a comprehensive echocardiography, which revealed a poor left ventricular contraction with LVEF of 28% (biplane Simpson method), a severe LVOT obstruction with a pressure gradient of 73 mmHg due to an obvious SAM, and a significant mitral regurgitation secondary to SAM (Figure 2 and Supplement video 2).
The echocardiogram performed on 4th day postoperatively showed complete relief of left ventricular outflow tract (LVOT) obstruction. (a) No SAM was seen on the three-chamber view. (b) No flow acceleration nor mitral regurgitation on the three-chamber view with color mapping. (c) Patent LVOT and regular LV shape. (d) No flow acceleration nor mitral regurgitation on the five-chamber view with color mapping. The Supplement video 3 and Supplement video 4 provide a better appreciation of normal LV shape, good LV contraction, and patent LVOT.
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Parallel, the MR reversed from severe to mild degree as being observed preoperatively, and the LVEF gradually returned to normal (Figure 3).