ABC | Volume 111, Nº3, September 2018

Case Report Silveira et al Partial papillary muscle rupture and early severe obstructive bioprosthetic valve thrombosis Arq Bras Cardiol. 2018; 111(3):430-433 Figure 1 – Transoesophageal echocardiogram two-chamber view showing a 9 mm disruption of the posteromedial papillary muscle (pointed with an arrow) consistent with a contained, but morphologically imminent rupture, leading to a broad posterior leaflet prolapse and a severe mitral regurgitation with an eccentric jet. LA: Left Atria; LV: Left Ventricle. Figure 2 – Transoesophageal echocardiogram long axis view and 3D zoom on face view of the mitral valve presenting a significant thickening of mitral bioprosthetic cusps due to thrombotic material deposition, leading to severe obstruction of the prosthetic valve and a large mural thrombus covering the left atrial posteroseptal wall (pointed with an arrow). BPMV: Bioprosthetic Mitral Valve; LA: Left Atria; LV: Left Ventricle. 100%. 4,5 Although partial PMR may be more difficult to identify than complete rupture, it should always be closely investigated in the setting of a flail/prolapse mitral leaflet. 5 In our case, only TEE evaluation provided a full characterisation of mitral valve structure and an accurate identification of the mitral valve apparatus disarray. Due to the adverse hemodynamic complications associated with PMR, emergent identification and treatment are essential to improve patient outcomes. The natural history of post-MI PMR is extremely unfavourable under medical treatment alone. 6 Partial PMR is also considered a surgical emergency as most of the cases will progress to complete rupture. 7 In our case, the instability of the sub-valvular apparatus was notorious with potential imminent complete rupture, as can be seen in Figure 1. Bioprosthetic valves are advantageous over mechanical ones due to their comparatively lower incidence of thromboembolic events and avoidance of long-term anticoagulation. Clinically significant bioprosthetic valve thrombosis (BPVT) is considered a rare phenomenon, however accumulated evidence suggests that it is an under-recognised 431