Perforation of the membranous atrioventricular septum caused by infective endocarditis in a patient with a unicuspid aortic valve

Transthoracic echocardiography showed moderate aortic stenosis with calcification (peak velocity of 3.67 m/s, mean aortic valve gradient of 31.6 mmHg, aortic valve area of 0.99 cm2) and moderate aortic regurgitation. See PDF.] a Transesophageal echocardiography showed wall thickening from the aortic sinus to the atrial septum, abscess, and LV-RA shunt flow near the vegetation. b Transthoracic echocardiography showed the vegetation near the tricuspid valve (white arrowhead). c Transesophageal echocardiography showed a single commissure (yellow arrowhead), rounded leaflet-free edge (yellow arrow) on the opposite side of the commissural attachment zone, and an eccentric valvular orifice. Declarations Conflict of interest Yukiko Sugawara, Atsushi Kobayashi, Yuki Muto, Takashi Igarashi, and Yasuchika Takeishi declare that they have no conflicts of interest.