A Successful Case of Open Heart Surgery for a Ventricular Septal Defect with Second-degree AV Block in a Dog

Abstract

A 19-month-old female Jomon-shiba dog with the main complaint of cardiac murmur was diagnosed by echocardiography and cardiac catheterization as having a membranous ventricular septal defect with second-degree AV block. It was also confirmed that the dog was suffering from consequent overload of blood flow in the left ventricle. Therefore, open heart surgery was performed with mildly hypothermic extracorporal circulation to correct the septal defect. Postoperative auscultation did not show any detectable murmur, and echocardiography showed that overload of blood flow in the left heart had diminished. The dog recovered without any complications, and has been doing well since the surgery. Second-degree AV block was found to have disappeared completely five months after surgery. It is probable that the improvement of the left ventricular blood flow caused the disappearance of the second-degree AV block.