Working Toward a Genetic Test for Heart Arrhythmias

Cardiac arrhythmias are thought to be an important cause of sudden death in horses during exercise. Most horses that develop arrhythmias have no underlying structural heart disease, making it challenging to detect animals that may succumb to the condition. Studies in human athletes with arrhythmias, but no underlying heart disease, show the condition is almost exclusively caused by genetic mutations. Researchers will test if genetic mutations found in a small number of Standardbred racehorses with these arrhythmias are associated with cardiac arrhythmias in a larger group of Standardbred racehorses. If successful, the team will use this information to develop genetic tests as well as other screening protocols for early identification of horses at increased risk of developing cardiac arrhythmias, with the goal of reducing sudden death caused by this condition.