Treatment of focal junctional tachycardia using ivabradine in a dog

Abstract A 10‐year‐old labrador retriever was referred as an emergency due to ascites and lethargy. Physical examination revealed a regular tachycardia at 160 beats per minute with a Grade 3/6, left apical systolic heart murmur. The dog was diagnosed with severe myxomatous mitral valve disease with biventricular congestive heart failure (mild pulmonary oedema and severe ascites) and focal junctional tachycardia. Congestive heart failure was managed with pimobendan, furosemide and benazepril/spironolactone. Ivabradine, a funny channel blocker, was used for rate control of the focal junctional tachycardia, and the dog achieved adequate rate control with monotherapy. The dog was euthanased 10 months after the initial presentation due to refractory congestive heart failure. This case report suggests that ivabradine might be useful for rate control in focal junctional tachycardia, but further studies are required to confirm this observation.