Aortocardiac fistula is a broad term used to describe defects between the aorta and other cardiac chambers that can occur in humans and animals. A 1.5-year-old, 1.7 kg, male castrated Holland lop rabbit () was presented for a two-week history of a heart murmur with corresponding cardiomegaly on radiographs. Physical examination confirmed a grade-V/VI continuous heart murmur on the right sternal border with a regular rhythm and a gallop sound. Echocardiography revealed an aortic-to-right-atrial fistula causing severe left-sided volume overload. Based on the echocardiographic findings, rupture of the right aortic sinus was suspected. Due to the poor prognosis, euthanasia was elected. On necropsy, a fistula was found connecting the right aortic sinus with the right atrium, without evidence of an inflammatory response nor evidence of an infectious etiology. The sudden onset of a heart murmur supported acquired fistulation from a ruptured aortic sinus (also known as the sinus of Valsalva), though a congenital malformation could not be completely excluded.

中文翻译：

---

宠物兔（Oryctolagus cuniculus）右主动脉窦自发破裂导致无菌主动脉心房瘘

主动脉心瘘是一个广泛的术语，用于描述人类和动物中可能发生的主动脉和其他心腔之间的缺陷。一只 1.5 岁、1.7 公斤重的雄性去势荷兰垂耳兔 () 因有两周的心脏杂音病史，并在 X 光片上显示相应的心脏肥大。查体证实胸骨右缘有V/VI级连续性心脏杂音，节律规则，有奔马律声。超声心动图显示主动脉至右心房瘘导致严重的左侧容量超负荷。根据超声心动图检查结果，怀疑右主动脉窦破裂。由于预后不良，选择安乐死。尸检时，发现连接右主动脉窦和右心房的瘘管，没有炎症反应的证据，也没有感染性病因的证据。突然出现的心脏杂音支持主动脉窦破裂（也称为瓦尔萨尔瓦窦）的后天性瘘管，但不能完全排除先天性畸形。