Schematic of the 2-sinus BAV phenotypes as seen by the transthoracic echocardiogram parasternal short axis. Applicable to similar tomographic views obtained from cardiac computed tomography and cardiac magnetic resonance, the figure demonstrates 2-sinus BAV phenotypes as zoomed views of the base of the heart for anatomical landmark correlation. (Left panels) (1) 2-sinus laterolateral BAV with only 2 distinguishable aortic sinuses in diastole and 2 cusps of roughly same size and shape, each occupying 180° of the circumference, with a 180° angle of the commissures. Note that although it is possible to suspect right non-fusion, the landmark anatomical relations are not clear because both the normal geographic ‘left’ and ‘non-coronary’ cusps occupy portions of the normal geographic location of the ‘non-coronary’ cusp, and the posterior commissural line is almost aligned with the interatrial septum, bisecting the geographical location of the normal non-coronary cusp (Figs 5 and 12). The 2-sinus BAV laterolateral phenotype has 1 coronary artery arising from each sinus. (Right panel) (2.A) A 2-sinus anteroposterior BAV with only 2 distinguishable aortic sinuses in diastole and 2 cusps of roughly same size and shape each occupying 180° of the circumference, with a 180° angle of the commissures. Note that although it is possible to suspect right–left fusion, the landmark anatomical relations are not clear because the commissural line actually bisects the normal geographical location of the left cusp, such that both anterior and posterior functional cusps appear to have a ‘piece’ of the left cusp (see Figs 5 and 12). (2.B) A 2-sinus anteroposterior BAV that resembles a fused right–left fusion but without a raphe, with only 2 distinguishable aortic sinuses in diastole and 2 same size/shape cusps each occupying 180° of the circumference. The 2-sinus anteroposterior BAV may have coronary arteries arising from each cusp (2.A) or from the anterior cusp (2.B). Modified from Michelena et al. [10] with permission from Elsevier. A: anterior cusp; BAV: bicuspid aortic valve; L: lateral cusp; P: posterior cusp.