[Effect of drug therapy of hyperthyroidism on the electrophysiological parameters of the heart]

Investigations of heart automatism have been performed in 10 patients with hyperthyreosis prior and after the euthyreosis obtaining with the methizol therapy. The control group consisted of 34 healthy volunteers. The electrophysiologic parameters of heart were determined by the transoesophageal stimulation of atrium using the method of single impulse and rapid stimulation. Instantly after obtaining the remission the normorhytmia has been observed; moreover, the significant elongation of the effective time of atium refraction and of the border interval, has been noted; the last two parameter were shorter than in the control group. The normalization of the border atrioventricular conduction and the sinusal rhythmus return as well as appearance in half of patients treated of latent block of intracardial conductivity has also been stated. According to the authors' opinion the early period after the obtaining of euthyreosis by the use of methizol is characterized by cardiological risk.