MEDBULLETIN MARCH 2019

Question:

A 24-year-old male patient sees you for exertional chest tightness. He is known to have a murmur since childhood. A transthoracic echo is arranged. The figure shows parasternal images obtained using 3-dimensional acquision: long-axis view (left panel) with a perpendicular plane placed across the image, and the corresponding short-axis view (right panel). LV denotes left ventricle; RV, right ventricle; LA, left atrium.

Which of the following are true?

1. An anomalous coronary artery should be excluded.
2. This patient is at elevated risk of a thoracic aortic aneurysm.
3. Cascade screening in first-degree family members should be considered.
4. This condition is twice as common in males as in females.
5. All of the above are correct.

Answer:

Diagnosis is bicuspid aortic valve, correct answer is 5.

Bicuspid aortic valve (BAV) is the most common congenital abnormality of the heart. It occurs in 1 – 2% of the population and is twice as common in males. It is usually the result of fusion between left and right aortic valve cusps (80%), and less frequently of the right and non-coronary cusps (10 – 20%). Fusion between left and non-coronary cusps is rare.

A key aspect of this condition to keep in mind in clinical practice is its association with other vascular and connective tissue defects, especially (i) anomalous coronary arteries, (ii) coarctation of the aorta, and (iii) aortic aneurysms. This is important as BAV is quite common. Interestingly, many practitioners are very aware of the related connective disorder Marfan’s syndrome, and its potential for acute aortic syndromes. However, some reports have found that BAV accounts for a larger number of such catastrophic events due to the fact that its prevalence in the population is so much higher.

The genetics of BAV follow an autosomal dominant mode of inheritance with incomplete penetration. Concerns regarding the associated aortopathy have led to recommendations to carry out family screening in first degree family members with echocardiography.