A 20-year-old man is referred for further evaluation of hypertension. He has remained hypertensive despite a 12-week trial of β-blocker treatment. Examination reveals a right upper extremity BP of 150/100 mmHg and a right lower extremity BP of 130/90 mmHg. HR is 88 bpm. There is brachial– femoral pulse delay. The rest of the physical and neurologic examinations are within normal limits. A TTE confirmed a diagnosis of coarctation of the aorta, with a maximum gradient of 30 mmHg. He is referred for cardiac catheterization. Intervention for coarctation is recommended when the coarctation gradient is greater than which of the following?
20 mmHg. Intervention for coarctation is recommended in those with a peak-to-peak coarctation gradient greater than or equal to 20 mmHg. In the presence of significant collateral vessel blood flow, catheter-based and Doppler systolic gradients may underestimate the degree of obstruction and intervention may be considered with gradients <20 mmHg in this setting. The most appropriate intervention for adults with native coarctation of the aorta remains controversial and either surgical or percutaneous intervention may be considered according to anatomy, comorbidities, center outcomes, and patient preference. In most ACHD centers, stenting has replaced balloon dilatation as the percutaneous intervention of choice, although this is not recommended in those with long segments of coarctation, vessel tortuosity, and transverse arch hypoplasia. Early mortality is usually less than 1% for primary operation in aortic coarctation.
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Which of the following is the most common coronary artery anomaly?
Left coronary artery arising from the right sinus of Valsalva.
Which of the following statements about coronary arteriovenous fistula is true?
Spontaneous closure rarely occurs. Coronary fistulae rarely close spontaneously. The most common origin of coronary arteriovenous fistula is the right coronary artery, with a fistulous communication into the RV, RA, or coronary sinus (appearance on echocardiography demonstrated on the next page). Less commonly, it empties into the LV, LA, or PA. Complications may include CHF from left-to-right shunt, bacterial endocarditis, coronary ischemia, and rupture or thrombosis of the fistula. Surgical closure is associated with a good outcome (figure below).
The right coronary artery fistula (red arrow) is seen in transthoracic short- axis (SAX) views arising from the right coronary cusp of the aortic valve (A) confirmed with color flow Doppler (B). In this case, the right coronary fistula drained into the right atrium (C) via a dilated coronary sinus (D). PLAX, parasternal long axis.
Which of the following differentiates valvular aortic stenosis from subvalvular aortic stenosis?
Valvular calcification. Both valvular and subvalvular aortic stenoses have male preponderance and may be associated with dilatation of the ascending aorta. The indications and risk of operation are similar. Although aortic regurgitation is more common in subvalvular aortic stenosis, it may also occur in valvular aortic stenosis. Valvular calcification is usually not observed in subvalvular aortic valve stenosis.
Echocardiography in a 20-year-old asymptomatic man reveals a subaortic membrane with a peak gradient of 20 mmHg. The aortic valve remains mobile, but there is associated mild to moderate aortic valve insufficiency. LV size is normal ejection fraction is 60%.
What should you advise this patient?
Transluminal balloon dilatation is the best treatment option in this case. Subaortic valve stenosis involves the presence of a membranous diaphragm in the LVOT that creates a turbulent flow across the LVOT. This frequently causes damage to the aortic valve and may cause aortic valve insufficiency. Surgical intervention is recommended for patients with subaortic stenosis and a peak instantaneous gradient of 50 mmHg or mean gradient of 30 mmHg on echo Doppler. 1 Elective surgical resection is also indicated with lesser gradients <30 mmHg in the presence of progressive aortic regurgitation, LV systolic dysfunction (<55%), or dilatation (end-systolic diameter >50 mm). Although recurrences occur, surgical resection is frequently curative. Patients with aortic regurgitation may undergo valve repair at the time of subaortic stenosis resection. AVR would best be avoided unless the valve is severely damaged as it would involve the patient having to have further surgery if a biologic valve or be on long-term anticoagulation if a mechanical valve.
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