Right sinus of Valsalva aneurysm ruptured into the right atrium in a dog

Masaki Kochi, Naoyuki Nishihara, Ryuhei Yamamoto, Tomoki Wada, Takuya Mori, Yuki Kurokawa, Kenji Kutara, Keisuke Sugimoto

A 10-year-old spayed female Shih Tzu was referred with a heart murmur. Auscultation revealed a continuous 4/6 right anterior chest basilar murmur. Chest X-ray showed no cardiac dilation or lung abnormalities. Short-axis view on transthoracic echocardiography revealed an aneurysmal dilation from the right sinus of Valsalva, with a defect opening into the right atrium. Color Doppler echocardiography showed a continuous, turbulent flow through the defect, entering the right atrium from the aorta, along with mild mitral and moderate aortic regurgitations. Pulmonary-to-systemic flow ratio was 1.11; no cardiac dilation was observed. Computed tomography angiography showed contrast influx into the right atrium, which connected to the right sinus of Valsalva aneurysm. The coronary arteries were normal. A ruptured right sinus of Valsalva aneurysm into the right atrium was diagnosed.