Electrocardiographic studies in the stumptail macaque (Macaca arctoides).

Our study has defined normal electrocardiographic standards for Macaca arctoides. It appears that certain species differences exist in the electrocardiogram (ECG) in monkeys and that different criteria for normality may be necessary. Thus, in apparently normal Macaca arctoides a high frequency of Q waves and ST segment elevations of the J point type are present compared to Macaca mulatta. It is suggested that normal ECG criteria be established for each species of monkeys to allow accurate interpretation.