A Canine Case of Bradycardia-Tachycardia Syndrome

Abstract

An approximately 10-year-old female Duchsfund showing weakness and syncope during exercise or excitement, was diagnosed as bradycardia-tachycardia syndrome (BTS) on electrocardiogram. The dog suddenly died 3 months later, regardless of exercise restriction, and histopathology revealed remarkable atrophy of the cardiac sinus node with decreased number of nodal cells and fibrosis within and around the atrophied sinus node. The interruption of contiguity between the sinus node and the right atrial myocardium might be related with the occurrence of BTS.