(15) Congenital Defects Causing Stenosis/Regurgitation

Relative to other valves, what is more commonly congenital than degenerative?

Pulmonary stenosis

What is the most common congenital heart defect found in adulthood?

Bicuspid Aortic Valve

How many cusps compose a bicuspid aortic valve?

Two cusps

A bicuspid aortic valve most commonly results from the fusion of which two cusps?

Right and left coronary cusps

In the most common form of bicuspid aortic valve, which cusp is larger?

The anterior cusp

In a bicuspid aortic valve with fused right and left coronary cusps, where do both coronary arteries originate?

The anterior cusp

What heart sound may be produced immediately after $S_1$ in a patient with a bicuspid aortic valve?

Systolic ejection click

If stenosis is present in a bicuspid aortic valve, what type of murmur is produced?

Crescendo-decrescendo systolic murmur

What is the systolic appearance of bicuspid aortic valve leaflets on imaging?

Doming or concave appearance

What is the diastolic appearance of bicuspid aortic valve leaflets on imaging?

Hammock-shaped or convex appearance

Which imaging view best demonstrates abnormal bicuspid aortic valve structure?

Parasternal short-axis (PSAX)

During which phase of the cardiac cycle must cusp number be evaluated to identify a bicuspid aortic valve?

Systole

Why is the fused raphe of a bicuspid aortic valve difficult to detect in diastole?

It cannot be reliably detected without the valve opening

What M-mode and 2D finding during diastole is characteristic of a bicuspid aortic valve?

Eccentric (off-center) line of closure

What common valvular pathology is associated with bicuspid aortic valves besides stenosis?

Aortic regurgitation

What calculation is used to evaluate the area of a stenotic bicuspid aortic valve?

Continuity equation

List three associated findings with a bicuspid aortic valve.

Coarctation, dilated aorta, and Marfan syndrome

How often should asymptomatic bicuspid aortic valve patients be screened?

Annually

When should bicuspid aortic valve patients be screened more frequently than once a year?

When aortic dilation is present

Who among the patient's relatives should be screened for bicuspid aortic valve defects?

First-degree family members

In PLAX, what are the characteristic findings of a bicuspid aortic valve?

Systolic doming, disproportionate cusp size, eccentric leaflet coaptation, and dilated aortic root/ascending aorta

In PSAX, what is the 'football-shaped' opening characteristic of?

Bicuspid aortic valve

Which echocardiographic views are used to evaluate a malformed aortic valve for stenosis and LVH?

Apical 5 and/or 3 chamber

Why is the suprasternal notch view important in bicuspid aortic valve assessment?

To evaluate the descending aorta for coarctation

Where is the membranous band of tissue located in Membranous Subvalvular Aortic Stenosis?

In the LVOT near the aortic valve

Which view is best for evaluating Membranous Subvalvular Aortic Stenosis?

Apical 5-chamber view

What cardiac muscle adaptation occurs as a result of Membranous Subvalvular Aortic Stenosis?

Compensatory LV hypertrophy

Why is the continuity equation invalid for determining the valve area in Membranous Subvalvular Aortic Stenosis?

The obstruction is in the LVOT, not the valve, and valve motion may be normal

How is PW Doppler used in the evaluation of subvalvular aortic stenosis?

To locate the obstruction by documenting increasing velocity as the cursor moves along the LVOT

After locating a subvalvular defect with PW Doppler, what is used to document peak velocity?

CW Doppler

What M-mode finding indicates subvalvular aortic stenosis?

Early systolic closure of the aortic valve

According to study notes, what is the M-mode triad for subvalvular stenosis?

Elevated velocity + normal valve opening + early systolic closure

According to study notes, what is the M-mode triad for valvular stenosis?

Elevated velocity + restricted valve opening

Where is the narrowing located in Supravalvular Aortic Stenosis?

Aortic root or ascending aortic lumen (above the valve)

What congenital syndrome is commonly associated with Supravalvular Aortic Stenosis?

Williams syndrome

In adults, what inflammatory condition can lead to supravalvular narrowing?

Takayasu arteritis

What happens to the continuity equation in cases of Supravalvular Aortic Stenosis?

It will NOT provide the correct valve area because the obstruction is in the aortic root

Why might CT or MRI be used instead of ultrasound for Supravalvular Aortic Stenosis?

Sonographic visualization of the ascending aorta may be limited

Where do normal aortic cusps coapt?

Approximately halfway between the annular base and the sinotubular junction

What defines Aortic Valve Prolapse?

Downward displacement of a cusp below the expected coaptation level

What is the most common association for aortic valve prolapse?

Bicuspid aortic valve

Besides bicuspid valves, name three conditions associated with aortic valve prolapse.

Aortic root dilation, mitral valve prolapse, and outlet VSD

What does a Cleft Mitral Valve commonly occur with?

Partial atrioventricular septal defect

Besides partial AVSD, what other septal defect is associated with a Cleft Mitral Valve?

Primum ASD

In PSAX, what imaging finding identifies a Cleft Mitral Valve?

A division or cleft of the anterior leaflet

What visual appearance does the mitral valve take in the PSAX view when it has a cleft?

It may appear to have three leaflets

What is the typical hemodynamic result of a Cleft Mitral Valve?

Mitral regurgitation

How does mid-diastolic doming in PLAX relate to Cleft Mitral Valve?

Doming of the anterior leaflet occurs without true stenosis

What is a Parachute Mitral Valve?

A congenital anomaly where one papillary muscle is attached to both sets of chordae

Which papillary muscle is usually present in a Parachute Mitral Valve?

Posteromedial papillary muscle

What condition does Parachute Mitral Valve mimic on Doppler echocardiography?

Mitral stenosis

What defines a Double Orifice Mitral Valve?

The presence of an accessory mitral orifice

What is the best view for visualizing a Double Orifice Mitral Valve?

Parasternal short-axis (PSAX)

What surgical device can create an appearance similar to a Double Orifice Mitral Valve?

MitraClip

How can you distinguish a congenital Double Orifice Mitral Valve from an acquired appearance?

The echogenic clip helps identify a device-created appearance

What is Cor Triatriatum?

A membrane across the mid portion of the left atrium that disrupts flow toward the mitral valve

Where is the membrane in Cor Triatriatum typically located relative to the fossa ovalis?

Above the level of the fossa ovalis

What unique 2D imaging appearance is produced by Cor Triatriatum?

The appearance of three atrial chambers

What type of inflow obstruction is caused by Cor Triatriatum?

Supravalvular inflow stenosis

What valve pathology does Cor Triatriatum mimic?

Mitral stenosis

What percentage of patients with Cor Triatriatum also have an ASD?

$$80\,\%$$

Can Cor Triatriatum occur in the right atrium?

Yes, but it is less common

Where is the obstructing tissue located in Supravalvular Mitral Stenosis (Ring)?

At the level of the mitral annulus (below the fossa ovalis)

Name one complex of defects associated with a Supravalvular Mitral Ring.

Shone complex

When does congenital Mitral Valve Prolapse (MVP) typically present?

Most commonly occurs as a congenital disorder but may not present until later in life

What is Pulmonary Vein Stenosis?

Narrowing of one or more pulmonary veins at their connection with the left atrium

What hemodynamic condition can be caused by pulmonary vein stenosis?

Pulmonary hypertension

What right-heart adaptations result from pulmonary vein stenosis?

RV hypertrophy and RV/RA dilation

During Doppler evaluation of Pulmonary Vein Stenosis, what happens to peak systolic ($S$) and diastolic ($D$) velocities?

Both peak systolic ($S$) and peak diastolic ($D$) velocities are increased

What Doppler finding may be seen between systole and diastole in pulmonary vein stenosis?

Flow reversal

Which congenital aortic defect is associated with Williams syndrome?

Supravalvular Aortic Stenosis

How are abnormal cusp numbers or structures classified in valvular assessment?

Valvular anomalies can cause stenosis and/or regurgitation

In PSAX, three cusps found with a raphe is suggestive of what?

Bicuspid Aortic Valve

What is the high-yield Registry clue for Cor Triatriatum?

Membrane within LA; three-chamber LA appearance; supravalvular inflow obstruction

What is the high-yield Registry clue for Parachute Mitral Valve?

Single papillary muscle; restrictive inflow; resembles mitral stenosis