[Various diagnostic criteria for abnormal signs of the artificial pacemaker examined by transesophageal electric stimulation of the left atrium].

Forty eight patients with abnormal sinus node were subjected to transesophageal electric stimulation (TES) of the left atrium to assess the length of poststimulation pauses (PSP) and the first 5 spontaneous sinus cycles after TES cessation. Higher values of PSP were found in patients with the sick sinus syndrome than in healthy subjects. Transition of TES to sinus rhythm is of practical value. In patients with the sick sinus syndrome, the first sinus contraction was shorter by 4.6% than the last PSP after TES (the respective value being 16.6% in healthy subjects), whereas this parameter was 20.9% (p less than 0.01) in patients with autonomic dysfunction of the sinus node. Hence, the functional potentialities of sinus node activity recovery are inconclusive with its various abnormalities, which may serve as one of differential diagnostic criteria for organic or functional pathology of a cardiac pacemaker.