[The modification of the effects of calcium on the heart using beta-adrenergic blockers]

To reduce unwanted effects of calcium upon the heart, in particular in cows during the treatment of hypocalcaemia, experiments were carried out in isolated hearts of guinea pigs and in conscious rabbits, to show whether beta-adrenergic blocking agents are able to antagonize these effects. It was found that calcium effects in the second phase which is characterized by a tachycardia, are antagonized by carazolol, which was used for these experiments.