[Value of statistical analysis of cardiac rhythm for the prognosis of electric instability in patients with acute myocardial infarction].

Patients with acute myocardial infarction and acute hemodynamic disorders were divided into 2 groups: 56 patients with severe arrthythmias (group 1) and 29 patients without heart rhythm disorders (group 2). Sinus rhythm analysis, making use of the computer technology and a specifically designed cardiac rhythm analyzer, RKAS-1, demonstrated changes, typical for patients at risk for severe arrhythmias. Segments of rigid rhythm alternating with those of high variability on the rhythmogram are a visual sign of electric instability of the heart. This rhythmic variability may be qualified as a result of discrupted adaptation of the sinus node. Mathematical analysis of statistical rhythm characteristics demonstrated typical indicators of the risk of electric instability. They are sigma 15 min between 2.73 and 7.4 ms and RR/sigma between 10.5 and 41.1, while P3 is less than 25%.