The effect of sulfonamide administration on cardiac function in the dog

The effect of various sulfonamide drugs on the electrocardiogram was studied in thirty-nine dogs.Sulfonamide administration had no effect upon the cardiac muscle and conducting system which could be demonstrated by the electrocardiogram in thirty-two dogs (82 per cent of the number studied), even though eleven of these dogs showed conduction defects before treatment.Electrocardiographic abnormalities consisting of slight S-T segment deviation and change in direction of T wave occurred in seven dogs during medication and indicated some myocardial involvement. These changes were transient and disappeared after drug administration was stopped in all except three cases. The possibility that these electrocardiographic changes were the result of morphologic changes in cardiac muscle caused by sulfonamide sensitization is discussed.