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Biomedical subjects

S S Grigorov

Publications and source records attributed to S S Grigorov.

At least 19 recordsLinked to original sources
PubMed1987

[20-year experience with continuous endocardial stimulation of the heart].

Twenty years' experience with continuous endocardial stimulation of the heart is summed up. The bulk of the reviewed data falls to the period of 1980 through 1985, when 1776 primary implantations were performed, whereas more than 3,000 implantations have been performed in the past 6 years. Opinions are voiced on many aspects related to endocardial stimulation. Endocardial application of electrodes is believed to be the principal method, while myocardial stimulation should only be done simultaneously with heart surgery. Electrode application via puncture is discussed with special reference to its advantages (possible application of two electrodes at once, small cosmetic defect) and possible side effects. The results obtained with a borer electrode, designed by the authors, are reported (130 cases). Complications associated with developing rhythm competition are discussed. It is proposed that the manufacture of asynchronous pacemakers be limited considerably, and that they should mostly be implanted in cases of clinically manifest myopotential inhibition.

Adolescent↗
PubMed1987

[Use of the electric stimulation of the heart in sick sinus syndrome (achievements and disputable problems)].

Experience with cardiac electrostimulation for the weak sinus node syndrome is presented. Between 1982 and 1985, 296 primary pacemaker implantations were performed, or 21.44% of all primary implantations performed over that period. The weak sinus node syndrome was diagnosed on the basis of ECG, Holter's monitoring and the atrial stimulation test. Initial atrioventricular conductivity disorders were recorded in 22.1%. Atrioventricular conductivity deteriorated in 16.1% of patients after 2 to 8 years of follow-up. The right ventricle was the principal stimulus application site in 267 patients, right-atrial stimulation was performed in 9, and double stimulation (radio-frequency right-atrial stimulation plus right-ventricular or right-atrial stimulation on demand), in 20. Permanent atrial fibrillation developed in 25% of 144 patients, followed up for 2 to 8 years, and the implant was removed in 5 (14%) patients.

Cardiac Pacing, Artificial↗
PubMed1986

[Laser endoscopic destruction of the atrioventricular junction of the heart conduction system in an experiment].

Feasibility and degree of local AV junction destruction were studied prior to the induction of complete transversal block on the model of 18 isolated perfused dog hearts, using endoscopic laser device, employing cardiofibroscope and laser Ne: YAG. Morphological pattern in the destruction zone is presented. The technique and device can be used for transvenous AV junction destruction.

Animals↗
PubMed1986

[Morphophysiological aspects of closed destruction of the conduction pathways of the heart].

An experimental study in an electrophysiological model of the human body showed defibrillator discharge current, used for closed electrodestruction of His' bundle in cases of drug-resistant supraventricular tachycardias, to cause a spark discharge and high-energy shock wave around the intracardiac electrode resulting in contusion of the heart. To stop the sparking, it is suggested that impulse voltage should be reduced while its duration should be prolonged in order to maintain local destruction potential. The relationship between the damaging effect of the impulse, and its force and duration was examined so that optimum action parameters could be established.

Body Surface Area↗
PubMed1986

[Hemodynamic aspects of the transvenous electrodestruction of the atrioventricular junction].

Transvenous electrodestruction of the atrioventricular junction is an effective method of surgical treatment for supraventricular arrhythmias (paroxysmal tachysystoles) refractory to medication. However, it is central hemodynamic status alone that can be an objective indicator of favorable clinical effect. Major central hemodynamic parameters were examined in 52 patients before and after the operation. Considerable late postoperative improvement of the general condition and normalization of major central hemodynamic parameters were noted in most cases.

Adult↗
PubMed1985

Differential diagnosis of rhythm disturbances induced by endocardial pacing.

Rhythm disturbances induced by endocardial pacing were studied in 15 patients. Atrial extrasystoles were found in 8, ventricular extrasystoles in 5, ventricular tachycardia in 1 and ventricular fibrillation in 1 patient. In all cases, an implanted pacemaker EKS-222 was used working in VVI regime. The connection of the above-mentioned rhythm disturbances with pacing is deduced from the stability of the coupling interval with the earlier induced complex, and from the presence of a negative P wave in standard leads II and III. A reliable criterion is in the authors' view, the disappearance of rhythm disturbances after the implanted pacemaker has been switched off.

Aged↗
PubMed1985

[Clinical use of transvenous electrodestruction of the atrioventricular junction in patients with supraventricular tachyarrhythmia].

The authors described 51 patients with different types of supraventricular tachyarrhythmias and ciliary arrhythmia paroxysms who showed resistance to drug therapy. All the patients were treated by the closed transvenous electrodestruction of the atrioventricular junction by producing a series of discharges with a defibrillator to the area of His' bundle, the power being 280-400 J. A stable and complete transversal blockade was obtained in 45 patients, in 6 patients the restoration of permeability in the atrioventricular system with frequent ventricular responses was observed, being the reason for repeated electrodestructions. No complications were observed. In the patients with blockade of the I-II degree tachycardia paroxysms either stopped or were milder and subjected to drug therapy. Biologically controlled electrocardiostimulators of the "demand" type were implanted to all patients after electrodestruction of the atrioventricular junction. Proceeding from the above the authors made a conclusion that the closed transvenous electrodestruction was a method of choice in the treatment of supraventricular tachyarrhythmias and ciliary arrhythmia paroxysms who showed resistance to drug therapy. It can be effectively used for seriously ill patients and elderly persons.

Adult↗
PubMed1984

[Determination of the life expectancy of patients undergoing continuous endocardial stimulation].

Using an actuarial analysis, the authors studied the time of survival in 120 patients with continuous endocardiac electrostimulation. There were 37 lethal outcomes by the end of the fourth year of the follow-up, with 31 of these patients aging from 65 to 100 years. The study of the survival rate in different age groups showed that the highest survival rate was in the group below 55 years and the lowest in the group of patients aged 75 to 100 years. The study of survival in different age groups is important for the prognosis of the necessary amount of cardiostimulators with energy sources varying in relation to their operational life time.

Adolescent↗
PubMed1983

[Programmed transesophageal electrostimulation of the left atrium].

In 34 patients with complex arrhythmias and conduction disturbances, programmed transesophageal electric stimulation of the left atrium was performed to determine the sinoatrial conduction time, relative refractory period of the atrioventricular conducting system, effective refractory period of the atrioventricular conducting system, that of the atria, that of an accessory tract in the Wolff-Parkinson--White syndrome, and stimulation parameters to trigger and reverse supraventricular tachicardia in order to define its mechanism. Potentials of a new noninvasive method of study are discussed.

Adult↗
PubMed1983

[ECG in endocardiac electric heart stimulation].

An electrocardiographic study was conducted in 126 patients with endocardial electric stimulation from the right-ventricular apex. All electrocardiograms were divided in 6 groups on the basis of the vector direction of the artificial ventricular complex in the frontal aspect and the complex' morphology in right and left standard leads. The clinical value of the proposed classification of artificial ventricular complexes is discussed.

Cardiac Pacing, Artificial↗