Effects of atropine, isoprenaline, neostigmine and practocol on cardiac arrhythmias induced by potassium in anesthetized dogs.

Either atropine, isoprenaline, neostigmine or practolol was given intravenously in therapeutic doses to dogs anesthetized with pentobarbitone sodium. Cardiac arrhythmias were induced by potassium chloride intravenously as a bolus injection in a dose of 0.3 mmol/kg. The standard electrocardiographic lead II was recorded continuously. pH, Po2 and Pco2 were checked from arterial blood samples before and after the injection. The isoprenaline treated dogs showed the smallest amount of arrhythmias and all the dogs survived. More severe arrhythmias were seen in the neostigmine and practolol treated dogs and the most severe occurrences were encountered in the atropine treated dogs.