[Phenomenon of a complete interventricular (interatrial) block]. / Fenomen polnoi mezhzheludochkovoi (mezhpredserdnoi) blokady.

In 21 cases of separate cardiac cavity excitation (20 of separate ventricular excitation (SVE) and one of separate atrial excitation), 40 right and left QRS complexes were obtained by routine, prolonged and synchronous ECG recording in various standard leads. A differential diagnosis was made between fusion QRS complexes and right and left QRS complexes. Three criteria of fusion ventricular complexes were found to be undiagnostic for right and left ventricular complexes in SVE. SVE has its own electrocardiographic criteria: (1) heterodirectional P waves or QRS complexes separated and unseparated from each other by an isoelectrical interval of less than 0.15 or less than 0.25 s, respectively; (2) in SVE, P-R interval may be no more than 0.06 s shorter than sinus P-R interval; (3) the end vector may be different from or similar to the sinus one. The basis for separate cardiac cavity excitation is functional longitudinal interatrial or interventricular blockade.

[Mechanism of the occurrence of ventricular bigeminy]. / K mekhanizmu vozniknoveniia zheludochkovoi bigeminii.

Twenty-seven patients, aged 15 to 77, with a variety of cardiovascular diseases and bigeminy, and 3 normal subjects were investigated, using exercise and atropin tests. Electrocardiograms were recorded at pre-ectopic intervals of no more than 0.55 sec in bigeminy and polygeminy. The common divisor for interectopic intervals, ectopic complex interpolation, P-Q and Q-T intervals of the main complex and the presence of a wave on the ascending or descending slope of the R wave in sinus QRS complex were determined. Three mechanisms were identified to explain ventricular bigeminy developing during the third phase of action potential and the supernormal myocardial excitation period. A risk group was identified with respect to persistent bigeminy, incorporating patients with the short P-Q syndrome and signs of the typical or atypical Wolff-Parkinson-White syndrome.

[Mechanisms of the occurrence of parasystole and extrasystole]. / O mekhanizmakh vozniknoveniia parasitolii i ékstrasistolii.

Mechanisms involved in the development of parasystole and extrasystole are substantiated on the basis of vast clinical material (261 patients with parasystole and 45 with extrasystole). The use of functional tests employing exercise and atropine contributed to both the correct diagnosis of parasystole and extrasystole and a logical explanation of the mechanisms governing their development. Prolonged ECG recording identified, for the first time ever, the limits of the maximum admissible coupling interval for normotopic extrasystole, as the preliminary diagnosis of the nature of the arrhythmia was only made after the said tests. Parasystole was shown to be rooted in a pathologic automatism, and extrasystole, in the summation of extrasystolic focus potentials and the principal pacemaker potential during movement as well as the principal pacemaker impulse along the route of the minor circular wave on Purkinje' level. The localization of ectopic foci in parasystole and extrasystole confirms the hypothesis of the mechanisms involved in these arrhythmias. A parallel study of parasystole and extrasystole defined parasystole as active heterotopia, and extrasystole, as passive heterotopia incapable of generating a rhythm.

[Differential diagnosis of linked parasystole and extrasystole]. / Differentsial'naia diagnostika parasistolii stseplennogo tipa i ékstrasistolii.

The differentiation between linked parasystole and extrasystole was based on functional tests with exercise and atropin as stimuli. A total of 116 patients (71 with parasystole and 45 with extrasystole) were investigated. Two mechanisms involved in parasystole with fixed links between ectopic complexes were identified: 1) a mechanism of simple quantitative correlation between two pace-makers, 2) a mechanism of the principal pace-maker being discharged with impulses from the parasystolic one. Extrasystole is based on the trigger mechanism of relationship between ectopic excitation and the impulse from the principal pace-maker. Prolonged ECG recording established limits for the maximum interval of links between monotopic extrasystoles and the interectopic interval for paired extrasystole. Extrasystole was shown to be incapable of generating a pace of its own, i.e. a succession of three or more ectopic complexes of similar morphology.

[Cordarone treatment of parasystole]. / Lechenie parasistolii kordaronom.

Cordarone was used in the treatment of 15 patients with various forms of parasystole. There were 9 cases with ventricular and 5 with atrial parasystole. Cordarone was prescribed according to the following schedule: 200 mg three times daily for the first 10 days and 200 mg twice daily in the next 20 days. A clear positive effect was produced in 14 patients. In 13 cases parasystoles disappeared on the first to tenth day of treatment. The number of parasystoles reduced considerably in one case. The drug had no positive effect on one patient.

[Electrocardiographic classification of total atrioventricular block]. / Elektrokardiograficheskaia klassifikatsiia polnoi atrio-ventrikuliarnoi blokady.

The introduced systematization of full atrioventricular blocks is a new method of analysis of ECG data in such patients. Singling out the arrhythmic form of a full atrioventricular block serves as a means of early diagnosis of the possible complications of making the prognosis of the patient's state, and as a method of choice of surgical or medical treatment; it permits timely implantation of a pacemaker, reduces the period of examination and therapy, which ensures an economic effect.