[Analysis of the structure of cardiac rhythm during treatment of auricular fibrillation with digitalis]. / Analiz struktury serdechnogo ritma pri digitalisnoi terapii mertsatel'noi aritmii.

The structure of cardiac rhythm was studied with the help of specialized computers during digitalization in 60 patients with atrial fibrillation of different etiology. The reduction of the heart contractions rate under digitalization is accompanied by certain changes in the structure of cardiac rhythm: the arrhythmic pattern of the ventricular contractions increases with a predominant growth of the number of long R--R intervals, the transitions from short intervals to longer ones become sharper, and portions of a relatively stable ventricular rhythm appear. Three main types of dynamics of the rhythm structure were distinguished on the basis of the changes in the interval R--R histogram. The described changes in the structure of cardiac rhythm are not specific, but when Digitalis drugs are used alone they can be used as additional criteria for digitalization.

[Analysis of the structure of cardiac rhythm in auricular fibrillation with the aid of a specialized computer]. / Analiz struktury serdechnogo ritma pri mertsanii predserdii s pomoshch'iu spetsializirovannoi EVM

In 37 patients with atrial fibrillation of varying etiology the electron-computer technique was used in recording the cardiointervalogram and interval histogram and also in determining a number of indices characterizing distinctive features of the R-R intervals distribution. When analyzing the available data not was taken of a tendency towards appearance of definite types of the interval histograms, variations in the mean level of the cardiointervalogram, resembling the so-called slow waves observable in the sinus rhythm. During repeated investigations made in the same patients features of a single type in the distribution of the R-R intervals were apparent. In the course of conservative therapy of atrial fibrillation a certain stereotypy in the R-R intervals distribution was noted, it being indicative of an increased arrhythmicity in the work of the heart occurring simultaneously with the slowing down of the cardiac contractions.