Diagnostic Pitfalls in Papillary Muscle Rupture-Associated Acute Mitral Regurgitation after Acute Myocardial Infarction

Papillary muscle rupture (PMR) is a rare and fatal complication of acute myocardial infarction (AMI). We report a case of acute mitral regurgitation (MR) due to PMR with pulmonary edema and cardiogenic shock following AMI with small myocardial necrosis. An 88-year-old woman was brought to our emergency department in acute respiratory distress, shock, and coma. She had no systolic murmur, and transthoracic echocardiography was inconclusive. Coronary angiography showed obstruction of the posterior descending branch of the right coronary artery. Although the infarction was small, the hemodynamics did not improve. Transesophageal echocardiography established papillary muscle rupture with severe mitral regurgitation 5 days after admission. Thereafter, the patient and her family did not consent to heart surgery, and she eventually died of progressive heart failure. Physicians should be aware of papillary muscle rupture with acute mitral regurgitation following AMI in patients with unstable hemodynamics, no systolic murmur, and no abnormalities revealed on transthoracic echocardiography.

Acute posteromedial papillary muscle rupture secondary to aortic valve endocarditis: a case report

Background Acute papillary muscle rupture due to infective involvement has been recognized as a complication of infective endocarditis. However, there is very limited literature describing the rupture of the posteromedial papillary muscle in primary aortic valve endocarditis without aortic root abscess. This report highlights the etiology of the papillary muscle rupture in the setting of primary aortic valve endocarditis and the importance of a multidisciplinary approach. Case summary An 81-year-old man without any heart failure symptoms presented with fever and loss of vision in his left eye. Initial echocardiography revealed moderate aortic valve regurgitation due to a perforated right coronary cusp without aortic root abscess, and his blood cultures were positive for Group G Streptococci. During adequate antibiotic therapy, he developed acute severe mitral regurgitation secondary to posteromedial papillary muscle rupture. Following emergent aortic and mitral valve replacement using bioprosthetic valves, he made excellent progress on a 6-week course of intravenous antibiotics. Discussion The echocardiography and the histological findings suggested that the main cause of papillary muscle rupture was most likely a metastatic focus of infection from the aortic valve via a regurgitant jet. Successful treatment of this fatal complication includes early diagnosis and prompt surgical intervention by a multidisciplinary approach.