2016 ACVIM Forum Research Abstract Program

In this study dofetilide and ranolazine were safe to administer in healthy horses and none of the compounds or the electrophysiological procedure caused myocardial damage in the horses. When dofetilide was given at a high dose the QT-interval prolonged indicating altered ventricular repolarization. Ranolazine showed an antiarrhythmic effect against acutely induced AF in horses. By combining dofetilide and ranolazine antiarrhythmic effects were obtained at low doses that would have been ineffective when administered separately. These findings lead us to believe that combination therapy may be a future treatment regime in equine AF. The aim of this study was to describe the occurrence of cardiac arrhythmias in young Standardbred horses that have recently entered training, to determine whether cardiac arrhythmias are consistently present during several training sessions and to evaluate if performance can be predicted based on the type and frequency of observed arrhythmias.