Aortic Stenosis

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 A "quick look" with ME AV SAX5 is very useful offering a look at the valve phenotype, degree of stenosis and any concomitant regurgitation. In addition bicuspid valves may be distinguished along with degree of calcification. 3D is difficult but may have utility as well. While simple trace of aortic valve area would seem simple it is not reliable .

The ME LAX view is ideal for measuring the annulus assessing leaflet motion and Doppler alignment. In addition associated aortic regurgitation may be evaluated along with LV thickness and aortic valve calcification.

The DTG LAX view is often the best view for Doppler interrogation for velocity (gradient) across the valve (severe velocity is greater than 4 m/s). A gradient greater than 36 mmHg is considered moderate and greater than 64 mmHg is considered severe stenosis. Here the gradient is over 90 mmHg and the aortic valve area is about 0.4 cm2, calculated by measuring VTI of the LVOT (dark shaded area) and the stenotic jet.

 The ME LAX view is ideal for visualizing the aortic valve, left ventricular outflow tract (LVOT) and the aortic regurgitation (AR) jet in relation to the mitral valve. Quantification severity is based on several factors that may be evaluated in this view including vena contracta (>0.6 cm) and AR jet width/LVOT ratio (>65% is severe).

 The ME AV SAX view is best for identifying  the number of cusps (bicuspid vs tricuspid) or valve phenotype and identifying prolapse or perforation. Color flow Doppler may offer insight into the presence f AR as well as severity as well. Other views such as the midesophageal ascending aorta short and long axis views may offer insight into possible aortic root dilation and its impact on AR.

The DTG LAX view is often the best view for using Continuous Wave Doppler to assess pressure-half-time (PHT). A shortened PHT (<200 ms) indicates rapid equilibration of pressures, often seen in acute or severe AR, along with color flow during diastole as a qualitative assessment. 

 The ME 5 Chamber view is useful for assessing residual aortic regurgitation and paravalvular leaks. As well sub-valvular masses and vegetations may be seen along with normal washing jets and dehiscence.

 ME LAX view is useful for assessing for paravalvular leak, valve function/residual regurgitation and vegetations/thrombus along with normal washing jets. 

 In the DTG LAX view gradients across the new valve may be assessed (the valve may not be large enough etc.). Gradients are calculated using the simplified Bernoulli equation such that velocity squared times four is the gradient across the valve, shown here with a velocity 1.35 m/s (gradient of  7.3 mmHg). In addition paravalvular leaks are best assessed in this view.

 A "quick look" with ME 5 is very useful offering a look at the septum, turbulent LVOT flow, anterior mitral valve leaflet morphology and mitral regurgitation. The patient with HOCM has a rotated heart such that it may require rotation with the probe o obtain a standard view. HOCM is managed by slow heart rate, afterload with phenylephrine and adequate ventricular filling to decrease septal anterior mitral motion. TEE can help with differentiating between mild SAM and severe HOCM.

Key findings in HOCM include asymmetrical septal hypertrophy seen here as a 2 cm septum (normal less than 1 cm). In addition systolic anterior motion (SAM) of the mitral leaflet causes obstruction and mitral regurgitation. Elongated mitral vave leaflets and anteriorly displaced papillary muscles contribute to SAM along with impaired LV relaxation and diastolic dysfunction. Finally a pressure gradient exists across the LVOT mimicking aortic stenosis.

 In the DTG LAX view, continuous wave Doppler is used to quantify gradients where a gradient greater than 30 mmHg indicates significant obstruction. In this rendering the velocity is around 3 m/s with a gradient of 38.3 mmHg. The Doppler profile is the typical "dagger shaped" waveform with a late-peaking systolic jet, characteristic of dynamic obstruction. 

The ME 4 is an essential view for MR in identifying primary vs secondary etiology as well as measuring vena contracta and establishing degree of severity. In addition jet direction (especially eccentric jets) may be determined along with secondary findings such such LV dilation.

 The ME LAX View has high utility along with the ME commissural and ME two chamber view in evaluating individual leaflets or scallops for function (here the P2 leaflet is prolapsing ad the left atrium is dilated). 

Probably the highest utility of 3D TEE is evaluating the mitral valve for the opportunity to repair the valve. Repair vs. replace is much better structurally but must be evaluated pre and post repair. Here the P2 scallop of the posterior mitral leaflet is seen en face prolapsing as the surgeon sees it. This is 3D Zoom and not an extremely difficult view to obtain. 

In the ME 4 a characteristic thickening, fusion and shortening of the chordae tendinae and mitral valve are seen in this patient with rheumatic mitral valve. A mosaic CFM pattern is seen due to the turbulent flow and flow acceleration across the stenotic valve. Significant dilation of the left atrium is also appreciated with a left atrium measuring 5.3 cm from top to the mitral annulus. along with reduced mitral valve mobility.

 In the TG Basal SAX view calcification of the mitral valve leaflets is noticed along with commissural fusion causing a narrow "fish mouth" opening and reduced mobility. Planimetry is useful and mitral valve area is approximately the same as measurements using continuous wave Doppler.   

 The DTG LAX view offers the ability to line up continuous wave Doppler and obtain precise velocities along with pressure half-time (PHT) which may be used to calculate valve area. In addition gradients across the valve may be assessed, with gradients > 5 mmHg considered to be marginal and > 10 mmHg to be unacceptable. This is key when performing mitraclip valve repairs. Here the velocity is 1.8 m/s, translating into a gradient of almost 13 mmHg across the mitral valve (severe mitral stenosis)

ME Bicaval View is the best for assessing ASD PFO or other interatrial communication. This and other TEE views are essential in defining morphology and type of ASD (secundum, primum, sinus venosus vs, coronary sinus ASD).  Color flow Doppler typically shows a left-to-right shunt. TEE can help calculate the Qp/Qs ratio (pulmonary-to-systemic flow) where a ratio of >1.5:1 indicates a hemodynamically significant shunt.  In this ASD the flow is left to right which is typical unless there is Eisenmenger physiology.

In this ME 4 view findings of right-sided volume overload include dilation of the right atrium (RAE) and right ventricle, and interventricular flattening during diastole.  

ASD is very common following atrial fib ablation or Watchman, the key is whether it is large enough to create an an issue or whether there is right to left instead of left to right flow. This  ME AV SAX view is typically used to cross the septum then evaluate the resulting ASD. Here the congenital ASD is significant and pulse wave Doppler or continuous wave Doppler may be used to assess flow.