[Impact of the time of outpatient monitoring of patients with implanted pacemakers to evaluate dangerous changes in the parameters of apparatuses]. / Vliianie srokov ambulatornogo kontrolia patsientov s implantirovannymi élektrokardiostimuliatorami dlia otsenki opasnykh izmenenii parametrov apparatov.

Patients with implanted pacemakers (PM) should pass outpatient monitoring at definite intervals given in the PM certificate. The paper shows that the monitoring periods in the patients are frequently violated, therefore the voltage of the PM battery is less than the critical level at which the PM is to be replaced. As the discharge of the battery is less than the critical level, the electronic unit of the PM begins first to regenerate an irregular sequence of stimulating pulses and then the generation of pulses stops. Thus, if the outpatient monitoring intervals in patients with implanted PM are over those given in the PM certificate, this will cause errors in encoding the causes of replacement of a PM, followed by dangerous changes in its parameters.

[A new method for the diagnosis of myocardial ischemia in patients with an implanted programmable pacemaker]. / Novyi sposob diagnostiki ishemii miokarda u bol'nykh s implantirovannym programmiruemym élektrokardiostimuliatorom.

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.

[20-year experience with continuous endocardial stimulation of the heart]. / 20-letnii opyt primeneniia postoiannoi éndokardial'noi stimuliatsii serdtsa.

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.

[Use of the electric stimulation of the heart in sick sinus syndrome (achievements and disputable problems)]. / Primenenie élektricheskoi stimuliatsii serdtsa pri sindrome slabosti sinusovogo uzla (dostizheniia i diskutabel'nye voprosy).

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.

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.

[Determination of the life expectancy of patients undergoing continuous endocardial stimulation]. / Opredelenie sroka zhizni bol'nykh s postoiannoi éndokardial'noi stimuliatsiei.

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.