Fig. 4

Preoperative coronary angiography of the patient with a mechanical mitral valve. A From the perspective of the liver position (RAO 20, CAUDAL 20), we can see the valve opening and closing, and at the same time, we can see that only one leaflet is located on the mechanical valve, but we cannot find the other leaflet. B From the perspective of CRANIAL 20, we can see the valve opening and closing, and at the same time, we can see that only one leaflet is located on the valve, but we cannot find the other leaflet. ML: mechanical flap; MMV: mechanical mitral valve; RAO: right front oblique position; CAUDAL: foot position; CRANIAL: head position