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Biomedical subjects

A M Zhdanov

Publications and source records attributed to A M Zhdanov.

At least 19 recordsLinked to original sources
PubMed2002

[Mental disorders in patients with complete heart block before and after a pacemaker implantation].

Mental disorders were studied in 52 patients with acquired complete heart block (CHB) before and after pacemaker implantation. Mental state of the patients was characterized primarily by borderline mental pathology--asthenia, affective pathology, hysteria spectrum disorders with autonomic symptoms and hypochondriac disorders. The structure and expression of mental disorders depend on premorbid personality traits of the patients, duration, severity and stage of the disease, the phase in respect to surgery intervention as well as preoperative period duration. Being the main therapy method, the operative CHB treatment, in general, positively influences the dynamics of mental disorders. However, in some cases, pacemaker implantation changes the behavior and quality of life of patients. Peculiarities of mental disorders in the CHB demand to include of psychopharmacotherapy and psychotherapy in treatment process.

Aged↗
PubMed1994

[Experience with the implantation of sensory multiple programmable pacemakers of the Siemens firm].

The paper summarizes the experience on 27 implantations of sensory multiprogrammable pacemakers (two-chamber Synchrony-II and one-chamber Sensolog-III) produced by Siemens-Elema. The implantations were performed in the Moscow Cardiostimulation Center in 1993. Primary pacemaker implantation was performed in 19 patients, 8 patients needed the replacement of one-chamber pacemakers because of the power source exhaustion or circulatory insufficiency. The two-chamber pacemaker was implanted to 14 patients with a complete AV-block and chronotropic sinus node incompetence and to 4 patients with sick sinus syndrome in intact AV-conduction. In 6 patients the one-chamber pacemaker was implanted to stimulate the right ventricle. They had permanent bradysystolic auricular fibrillation and complete AV block with persistent or transitory tachysystolic auricular fibrillation. 3 patients with sick sinus syndrome received one-chamber pacemaker. The authors think their experience with sensory Siemens-Elema pacemakers positive.

Adolescent↗
PubMed1994

[A new method for the diagnosis of myocardial ischemia in patients with an implanted programmable pacemaker].

Implanted programmable pacemaker (IPP) applicability for detection of myocardial ischemia has been tried in patients with continuous pacing (CP). 28 patients (mean age 59 +/- 9 years) on CP in VVI and AAI regimens because of arrhythmia and abnormal cardiac conduction underwent loading test with enhanced stimulation made with IPP on the changed program. Impaired local contractility (ILC) of the left ventricle was registered at two-dimensional echoCG. The test reached diagnostic criteria in 27 cases. The results of the test appeared positive in 11 patients whose ILC index increased from 3 +/- 3 to 9 +/- 5 (p < 0.01), on the average. The authors believe this variant of stress-echoCG applicable for diagnosis of myocardial ischemia in IPP patients. Limitations are indicated in AAI and VVI CP regimens.

Adult↗
PubMed1993

[Radionuclide ventriculography for evaluating left ventricular myocardial contractility in patients with implanted pacemaker].

An EKC-500 pacemaker was implanted in 16 patients with coronary heart disease (CHD) and 14 idiopathic conduction disturbance for complete atrioventricular block. After surgery, the patients underwent equilibrium radionuclide ventriculography by using a nuclear stethoscope at rest and during exercise at different stimulation rates with the aim of choosing their optimal values. It was established that patients with idiopathic conduction disturbances showed improved left ventricular contractility at all stimulation rates and their optimal values ranged 60-70 per minute. In patients with CHD, the stimulation rate of 60 impulses/min was optimal at rest, and with this, exercise resulted in a significant deterioration of myocardial contractility, but only the stimulation rate of 80 impulses/min led to a slight improvement, which was due to accessory mechanisms of contractility enhancement. The peak ejection rate was the most sensitive to progressive myocardial dysfunction, yet the basic contractility index was the mean ejection rate.

Arrhythmias, Cardiac↗
PubMed1991

[Rhythmographic analysis of atrial extrasystole in patients with sick sinus syndrome].

The comparative analysis of 141 electrocardiograms showing premature atrial contraction from 43 patients with the sick sinus syndrome and 19 subjects with normal sinus nodal function revealed new electrocardiographic signs suggesting sinus dysfunction: an increase in the postextrasystolic pause by more than 135% of the preextrasystolic interval; greater full compensatory pause values; extrasystolic appearance of a full compensatory pause with the coupling interval of less than 68% of the presystolic interval; an increase in the sinus cycle followed the postextrasystolic pause by greater than 50 msec. The proposed criteria show a 5.7-fold increase in the informative value of ECG analysis in the diagnosis of the sick sinus syndrome in premature atrial contraction.

Adolescent↗
PubMed1991

[Provocation of supraventricular arrhythmia in the diagnosis of sick sinus syndrome].

The diagnostic value of routine evaluations of sinus function and of analysis of sinus pause lengths were compared in 31 patients with a brady- and tachycardia types of the sick sinus syndrome after abolishing the tachyarrhythmic paroxysms provoked during an electrophysiological study. The study was performed by transesophageal electric stimulation. The sensitivity of the two modes of diagnosing the sick sinus syndrome was comparable: 55.5-65.2% for the former and 47.7-69.6% for the latter mode. Their concomitant application increases the diagnostic value of electrophysiological studies in patients with suspected brady- and tachycardia types of the sick sinus syndrome by more than 17%.

Adolescent↗
PubMed1989

[Potential of the method of transesophageal stimulation of the left atrium].

The authors provide the results of examining the conduction system of the heart in 623 patients with different disorders of heart conduction and rhythm by means of transesophageal pacing (TEP). The non-invasive electrophysiological examination of patients with sick sinus syndrome with latent disorders of atrioventricular (AV) conduction, and with supraventricular tachyarrhythmias turned out to be of high diagnostic value, inducing no complications. Application of programmed TEP (scanning extrastimulus on basis pacemaking) employed by the authors for the first time during TEP considerably widens the diagnostic possibilities of the technique permitting the measurement of the refractory periods of the conduction system (the refractory periods of the sinus node, atria, and AV-conduction system along normal and additional pathways), the performance of the trigger and removal of supraventricular arrhythmias with diagnostic and treatment purposes in view. The use of TEP for the treatment of patients with the syndrome of the prolonged QT interval and ventricular premature heart beat accelerates the choice of adequate antiarrhythmic therapy and raises its efficacy.

Adolescent↗
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

[P-synchronized ventricular stimulation in supraventricular tachycardia].

The author used P-synchronized stimulation of the ventricles to prevent tachycardia paroxysms in patients with frequent drug-resistant paroxysms of supraventricular tachycardia (SVT). Electrophysiologic examinations revealed additional conductive pathways functioning during tachycardia in the retrograde direction in 12 patients whereas in 6 cases tachycardia was accounted for by the mechanism of the re-entry of the excitation wave inside the atrioventricular node. The detected mechanisms of SVT development made it possible to use a method of its prevention by ventricular electrostimulation in the P-synchronized mode. Stimulation parameters were determined by a specially devised technique during electrophysiological examination. Following this stimulation, tachycardia attacks were completely prevented and attempts to provoke them by various types of stimulation were unsuccessful.

Adult↗
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↗
PubMed1982

[Use of P-synchronized electrical stimulation of the heart for preventing supraventricular tachycardia paroxysms due to accessory conduction pathways].

The paper deals with a possibility to apply P-synchronized ventricular stimulation for the prevention of frequent, drugirresponsive paroxysms of supraventricular tachycardia (SVTC) due to the accessory conduction pathways. During the electrophysiologic study of 5 patients with SVTC paroxysms, the presence of Kent's bundle conducting the impulses in a retrograde way has been revealed. The observed mechanisms of SVTC occurrence (delayed His-Purkinye system conduction in 2 patients and atrioventricular nodal conduction in 3 patients) enabled its prevention to be achieved by a method of ventricular electric stimulation in the P-synchronized regimen with a shortened atrioventricular delay in the impulse conduction. While performing this type of stimulation tachycardia episodes were completely terminated, and it was impossible to provoke them by different types of stimulation.

Adult↗