RT Book, Section A1 Shindler, Daniel M. A1 Shindler, Olga I. A1 Wright, Alicia SR Print(0) ID 1175625628 T1 Bicuspid Aortic Valve T2 Practical Echocardiography for Cardiac Sonographers YR 2020 FD 2020 PB McGraw Hill PP New York, NY SN 9781260457797 LK accesscardiology.mhmedical.com/content.aspx?aid=1175625628 RD 2024/10/15 AB Definition- Bicuspid aortic valve: two instead of three semilunar aortic valve cusps.- There are also rare patients with unicuspid and quadricuspid aortic valves.Cusp nomenclature- The conjoined cusp is usually wider than normal and contains a raphe.- Raphe: a ridge that extends from the aortic wall to the commissure of the conjoined cusp.Raphe height variants- No evident raphe, just a “fishmouth” systolic opening.- Shallow, difficult-to-image raphe.- Classic thick visible raphe.- Unusually tall raphe—rising as high as the free edge of the leaflets.Over time, the raphe may become calcified. Calcification is manifested on echo by acoustic shadowing past the raphe.Classification:- Type 1: Fusion of the right and left coronary cusp (larger sinus diameter) (70%–86% incidence).- Type 2: Fusion of the right and noncoronary cusp (associated tubular ascending aorta and dilated arch) (12%–28% incidence).- Type 3: Fusion of the left and noncoronary cusp (rare incidence).Imaging:- Parasternal long axis (PLAX) view provides the first clue to the presence of a bicuspid valve.- Asymmetric diastolic leaflet closure line located on an “outside third” of the sinus of Valsalva (Fig. 9-1).- Systolic doming.- Diastolic prolapse.Short axis (SAX) view is used for definitive diagnosis. Sometimes transesophageal echocardiography (TEE) is needed for confirmation.Diastole may fool you: The closed valve may look perfectly normal on echo when a nonthickened raphe is present.Look for a thicker than normal, partly unseparated raphe in systole.Look for the systolic “fishmouth” opening.A commissure line may continue “past the center” without bending.A commissure may violate the 10–2–6 o’clock location.When the intercoronary (right to left) commissure is abnormal (type 1), the systolic opening has a horizontal orientation.When the right-to-noncoronary commissure is abnormal (type 2), the systolic opening has a vertical orientation.Doppler evaluation of the systolic gradient in bicuspid aortic valves:- The maximum instantaneous Doppler gradient is typically higher than a peak-to-peak gradient measured by catheterization.- The mean Doppler gradient is closer to the peak-to-peak gradient measured by catheterization.- The discrepancy is explained in some cases by the presence of pressure recovery.- Direct planimetry of 2D and 3D echo images should be done when feasible (making sure the smallest possible, “mouth of the volcano,” true stenosis orifice is used).- In children with a stenotic bicuspid, or a unicuspid aortic valve, the presence of left ventricular hypertrophy indicates significant valve obstruction.- Bicuspid aortic valve is associated with coarctation of the aorta.