Jonderko G, Kocot E, Marcisz C. Z Gesamte Inn Med 1983 Jan 1;38(1):15-7. Investigations of the heart automatism were carried out in 8 persons with primary hypothyroidism before therapy and after euthyroid status procurement. In order to determine the electrophysiologic parameters there has been applied the transoesophageal atrium extrastimulus technique and the overdriving stimulation. There has been stated a positive effect of the thyroid function compensation upon the atrium refractory period, the atriumventricular conductibility and the refractory time of the total conductivity system. The authors suggest, that investigation, in which transoesophageal atrium stimulation has been applied, may belong to the methods of tracing the effect of hypothyroidism therapy.