P155 CT EVIDENCE OF PARTIAL ISCHEMIC PAPILLARY MUSCLE RUPTURE

Abstract

Abstract A 77–year–old man was referred for coronary CT following an episode of prolonged chest pain that occurred about 30 days earlier, with subsequent onset of dyspnea on moderate exertion. Coronary CT demonstrated right dominance, occlusion of the right coronary artery, as well as severe stenosis of the distal segment of the left anterior descending artery and of the first obtuse marginal branch. CT scan also showed an intraventricular image consistent with partial rupture of the posteromedial papillary muscle (Figure 1). The patient was transferred to the emergency department. An ECG showed signs of inferolateral necrosis. Transthoracic echocardiography confirmed akinesia of the inferior and inferolateral walls and of the basal segment of the inferior septum, with severe mitral valve insufficiency from anterior leaflet prolapse (A3 scallop) from partial rupture of the posteromedial papillary muscle (Figure 2). Transesophageal echocardiography confirmed the diagnosis (Figure 3). The patient was admitted to the CCU and underwent coronarography, which confirmed the severe triple vessel coronary artery disease with occlusion of the right coronary artery, and then urgent mitral valve replacement with bioprosthesis and aortocoronary bypass with saphenous vein grafting to the posterior descending artery. The postoperative course was uneventful. Ischemic papillary muscle rupture is a rare cause of mitral insufficiency. Papillary rupture typically occurs within 5 days of an acute myocardial infarction, and causes mitral insufficiency by prolapse and flail of one or, more rarely, both mitral valve leaflets. The posteromedial papillary muscle is most commonly affected, since the anterolateral papillary muscle has dual supply from the anterior interventricular artery and the circumflex artery. Papillary muscle rupture can be total or partial; however, most cases of partial rupture progress to complete rupture and therefore require urgent surgical treatment. The peculiarity of this case lies in the fact that it is the first case described in the literature of a papillary muscle rupture documented on CT.