Bicuspid aortic stenosis overview

Overview
A normal aortic valve has three leafs (it is a tricuspid valve), but some patients are born with a congenital abnormality in which the aortic valve has two leaflets (a bicuspid aortic valve).

Pathophysiology
A congenital bicuspid aortic valve may be associated with the development of either progressive clacific stenosis or regurgitation. What differentiates the pathophysiology of bicuspid aortic stenosis from other forms of aortic stenosis such as the degenerative aortic stenosis is the presence of concomitant valve disease, aortic root disease, and an increased incidence of coarctation of the aorta.

Epidemiology and Demographics
In this condition, instead of three valve cusps, the aortic valve has two cusps which results from the fusing of one of the commissures. Bicuspid aortic stenosis is the most common congenital abnormality of the heart accounting for 5% of congenital heart defects and it occurs in 1-2% of the population. It can be manifested as a murmur and usually has no long term health consequences, but if it does, the manifestation of aortic stenosis occurs 10 years earlier.

Risk Factors
Risk factors of bicuspid aortic valve to progress to stenosis are hypercholesterolaemia, hypertension and asymmetrical leaflets

Screening
First degree relatives of patients with bicuspid aortic valves should be screened using echocardiogram for its presence as there are evidence of familial clustering with autosomal dominant inheritance pattern.

Natural History
Typically, aortic stenosis due to calcification of a bicuspid valve appears earlier, at 40 to 50 years of age, whereas that due to calcification and degeneration of a tricuspid aortic valve appears later, at 70 to 80 years of age.

Videos
Below is the video of Dr. Lars Svensson, Cardiothoracic Surgeon and Director of the Aorta Center, at the Cleveland Clinic giving an overview of bicuspid aortic valve and its management.