Page 27 - Delaware Medical Journal - November 2015
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CASE REPORT
FIGURE 2
Color flow imaging shows turbulent flow (arrow) suggestive of LVOT obstruction at the level of the subaortic membrane.
that is primarily due to hypertrophic cardiomyopathy (HCM). HCM is a genetic disease of the heart muscle, which is characterized by asymmetric hypertrophy of the LV and is often associated with systolic anterior motion of the mitral valve and resultant mitral regurgitation. LVOT obstruction can be induced or increased by maneuvers that reduce preload (such
as Valsalva maneuver or dehydration), decrease afterload, or increase left ventricular inotropy (such as isoproterenol infusion) which translate into increased intensity of the systolic ejection murmur ausculted in the left sternal border. Other causes of dynamic LVOT obstruction are treatment with catecholaminergic drugs,2 following mitral valve repair,3 or after aortic valve replacement.4
mitral regurgitation was found. The presence of subvalvular AS was, therefore, highly suspected. The patient underwent transesophageal echocardiography (TEE), which showed a thin subaortic membrane arising from the interventricular and mild aortic regurgitation (Figure 3). Coronary angiography was unremarkable. She resection of the subaortic membrane.
DISCUSSION
Sub- or supravalvular AS is usually suspected when the valve anatomy is not stenotic, yet Doppler examination reveals high transaortic pressure gradients. Supravalvular AS is commonly caused tubular hypoplasia of the ascending aorta or discrete membrane at the sinotubular
or can have a dynamic component
FIGURE 3
Transesophageal echo demonstrates presence of a thin subaortic membrane (arrow) arising from the interventricular septum.
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