Most commonly, a BAV is associated with the congenital fusion of right and left coronary cusps, which is seen in 70–80 % of cases (Fig. 6.4). The other, less common fusion is of the right cusp and the posterior (noncoronary) cusp, which is seen in the other 20–30 % of cases [1].

Median raphe is typically (60 %) in the conjoint cusp. Differential point for acquired bicuspid AV: Raphe does not reach cusp margin.

BAV is a congenital disorder that affects 1–2 % of the population [2]. Males make up 70–80 % of cases. It is the most prevalent congenital heart abnormality.

BAV accounts for approximately half of all cases of AS, with a presentation typically in the 5th–6th decade. It also accounts for about one-fourth of all cases of AR, commonly presenting earlier in life.

A 2012 study of patients at necropsy found that 61 % of those with BAV had aortic stenosis [3, 4]. There is a significant association with aortic dilatation, with studies varying from 33 to 79 % prevalence depending on the study criteria. Increased risk for endocarditis has also been associated with BAV [4].

There does appear to be a significant genetic component to BAV. One epidemiological study showed a prevalence of 14.6 % of BAV in affected families, which is a much higher rate than the general population [5]. The risk of BAV among 1st degree relatives of an affected individual is 10 % [2]. A family history of BAV should raise suspicions during evaluation.

There is also a high association of BAV with other congenital anomalies including aortic coarctation, interrupted aortic arch, and other aortopathies [2].

Commonly asymptomatic and may be found as an incidental finding on an echo for another reason.

Symptoms of BAV are related to the pathologies closely associated with the anomaly, including AR, AS, and aortopathies.