Simon is a 16 year old Standard Poodle that came in for an exam. He has been experiencing some Ataxia (not noted so much on exam today) along with some staring off into space. He also has Anisocoria. I noticed an arrhythmia on exam along with a grade 2 HSM heard over the mitral valve. No history of syncope.

I did an EKG and it came back with multiple PVC’s. I wanted to start him on 5 mg/kg Mexilitine for the arrhythmia but decided I better do an echo to make sure his heart myocardium is not decompensating.

Simon is a 16 year old Standard Poodle that came in for an exam. He has been experiencing some Ataxia (not noted so much on exam today) along with some staring off into space. He also has Anisocoria. I noticed an arrhythmia on exam along with a grade 2 HSM heard over the mitral valve. No history of syncope.

I did an EKG and it came back with multiple PVC’s. I wanted to start him on 5 mg/kg Mexilitine for the arrhythmia but decided I better do an echo to make sure his heart myocardium is not decompensating.

On Echo I found a mild increase in LA/AO, myxomatous change to the Mitral valves and a large Mitral regurgitation with a velocity of 5.87 m/sec. I could not see any other abnormalites with CFI and Spectral doppler

I am going to attach a .jpg of the evaluation of the L ventricle. As you can see there are changes in the rhythm of IVS making placement of my measure a little tricky.

My ?

1. Is it safe to start the Mexilitine?

2. Would you start him on Pimobendan? He would not qualify IMO if I was going to use the standards of the Epic study. Yes I know he is not a small dog.

Owner is reluctant to do a cardio consult at 16 years of age.