Electrocardiographic study in the American Quarter Horse breed

An evaluation of the electrocardiographic profile of 50 clinically healthy Quarter Horses, with ages ranging from six months to 28 years old, 34 females and 16 males, was performed. Heart rate has not decreased with age, and duration of the QRS complex increased with the growth of the animal. The amplitude of the S and T1 waves were higher in male subjects than in female Quarter Horses. Avaliou-se o perfil eletrocardiográfico de 50 equinos da raça Quarto de Milha, clinicamente sadios, com idades variando de seis meses a 28 anos, sendo 34 fêmeas e 16 machos. A frequência cardíaca não diminuiu com a idade, e a duração do complexo QRS aumentou ao longo do crescimento do animal. A amplitude das ondas S e T1 foram maiores nos indivíduos machos do que nas fêmeas da raça Quarto de Milha.