Cittadini Francesca, Oliva Antonio, Arena Vincenzo, Minelli Natalia, Pascali Vincenzo L
From the *Institute of Forensic Medicine, and †Institute of Pathology, Catholic University, School of Medicine, Rome, Italy.
Am J Forensic Med Pathol. 2011 Sep;32(3):239-41. doi: 10.1097/PAF.0b013e3181d3ca7e.
Anomalies of the mitral subvalvular apparatus can include differing types of papillary muscles and chordae tendinae. Direct insertion of the anomalous papillary muscle or chordae tendinea into the anterior mitral leaflet and fusion to the ventricular septum are common findings related to these anomalies. Anomalous papillary muscles or chordae, especially those that insert directly into the mitral leaflets, play a role in obstructing left ventricular outflow by restricting the mobility of the leaflets and/or tethering them toward the septum, thus narrowing the left ventricular outflow tract (LVOT). The incidence of mitral valve anomalies associated with LVOT is probably underestimated. This topic is frequently studied, however, especially in the pediatric cardiac surgery milieu, because LVOT obstruction could have a surgical solution. We report a case of an 18-year-old woman affected by epilepsy since 5 months of age who was found dead in her bedroom. An uncommon anomalous papillary muscle/chordae was the main autopsy finding. This malformation causes direct continuity between an accessory papillary muscle and a mitral leaflet, resulting in a long rigid area that can cause dynamic late-systolic intraleft-ventricular obstruction. In our case, in the absence of any other pathologic findings or major structural abnormalities, we speculate that a malignant cardiac arrhythmia provoked by the accessory papillary muscle could be the cause of death.
二尖瓣瓣下结构异常可包括不同类型的乳头肌和腱索。异常乳头肌或腱索直接插入二尖瓣前叶并与室间隔融合是与这些异常相关的常见表现。异常乳头肌或腱索，尤其是那些直接插入二尖瓣叶的，通过限制瓣叶的活动度和/或将其拉向室间隔，在阻碍左心室流出方面起作用，从而使左心室流出道（LVOT）变窄。与LVOT相关的二尖瓣异常的发生率可能被低估。然而，这个主题经常被研究，尤其是在小儿心脏外科领域，因为LVOT梗阻可能有手术解决方案。我们报告一例自5个月大起就患有癫痫的18岁女性，她被发现死于卧室。一个不常见的异常乳头肌/腱索是尸检的主要发现。这种畸形导致副乳头肌与二尖瓣叶直接相连，形成一个长的僵硬区域，可导致动态晚期收缩期左心室内梗阻。在我们的病例中，由于没有任何其他病理发现或主要结构异常，我们推测由副乳头肌引发的恶性心律失常可能是死因。
