Athletic Heart Syndrome in the Sled Dog

Athletic heart syndrome is a medical condition common to the endurance athlete, whether human or canine. It is a characterized by the presence of bradycardia, arrhythmia in the form of P wave amplitude increase, QRS wave voltage and amplitude increase, ST segment elevation, and QT segment lengthening. Also indicative of athletic heart syndrome is hypertrophy of the cardiac muscle, mostly the left ventricle and ventricular septum, and presence of systolic murmurs. These findings are concluded through the use of auscultatory means as well as electrocardiography. Causes of athletic heart syndrome are most likely attributed to the physiologic response of the heart to endurance training, but genetics, hormonal responses, environment, and nutrition may all have an effect. Research in the field of canine athletic heart syndrome is severely lacking, and further elucidation of the causes and consequences of this medical condition in the canine endurance athlete may prove to be useful in both humans and canines in the related conditions of systolic anesthetic complications, training, nutrition, and sudden death syndrome.