[The value of digital-analog Holter monitoring systems in the noninvasive diagnosis of heart rhythm disorders].

By using the Custo Mega ECG monitoring system as an example, the value and efficiency of digital analog Holter monitoring systems in the non-invasive diagnosis of cardiac arrhythmias have been analyzed. The findings suggest that the Holter monitoring system produces high reliability, sensitivity (80.8-100%), and specificity (70.

[Ablation of ventricular tachycardia in thoracotomy without artificial circulation].

Seventeen patients were operated on for ventricular tachycardia (VT). Closed heart radical surgeries destroying the arrhythmia substrate were made without employing extracorporeal circulation. A VT episode was inducible in 16 (94%) patients for VT intraoperative mapping.

[Surgical treatment of Wolff-Parkinson-White syndrome: analysis of the methods and results].

The authors analyse the outcomes of surgical management in 400 patients with the Wolff-Parkinson-White syndrome who had been operated on in the All-Union Centre for Surgical treatment of Severe Cardiac Arrhythmias and Electrocardiostimulation. Unique surgical procedures were applied, which made it possible to perform cryodestruction of accessory atrioventricular pathways, without resorting to an extracorporeal circulation and without opening heart cavities. The procedures are demonstrated to be not inferior to operations using extracorporeal circulation.

[The effect of calypsol, thiopental sodium and fentanyl on the functional status of the sinoatrial node and the heart conduction system in patients with paroxysmal arrhythmias].

64 patients with paroxysmal arrhythmias caused in 44 cases by collateral atrioventricular pathways have been studied. Endocardial programmed electrical cardiostimulation was applied. It has been established that calypsol at a dose of 2 mg/kg significantly improves the functional state of the sinoatrial node, atrioventricular conduction and conduction in collateral atrioventricular pathways functioning both anterogradely and retrogradely.

[Laser destruction of the atrioventricular bundle using the cardiac endoscope].

The results of experiments where endoscopes of various makes were introduced into the right atrium under thoracotomy or transvenously are reported. After visual determination of the A-V node zone, laser coagulation was performed by Nd-YAG laser until complete A-V block was achieved. Various methods of laser cardiac endoscopy application are discussed.

[Cryogenic effect on the coronary arteries in animal experiments].

The present study was designed to examine both acute and chronic effects of cryothermia on the coronary arteries in the experimental model. Microscopic examination has revealed coronary intimal hyperplasia in the majority of coronary arteries at the site of cryogenic lesion. In some cases cryothermia was complicated by arterial thrombosis.

[Surgical treatment of children with ectopic atrial tachycardia].

Up-to-date electrophysiologic investigations of the heart, carried out in 212 children with arrhythmias, demonstrated a focus of ectopic atrial tachycardia in 21 (9.9%); 17 of those underwent long-term treatment (up to 10 years) with antiarrhythmic drugs. Kordaron produced a positive effect (discontinuation of the attacks) in 1 case only.

[Ambulatory electrophysiological diagnosis of heart rhythm disorders].

A noninvasive method of electrophysiologic investigation (EPI) making use of programmed esophageal electrostimulation of the heart has been developed on the basis of EPI carried out in 2158 inpatients (including 1273 procedures involving esophageal electrostimulation of the heart). Its introduction in an outpatient cardiologic clinic in Kaunas made it possible to investigate 522 patients with heart rhythm disorders in 1985 alone. Effective antiarrhythmic therapy could be selected for 389 (74.

[Transposition of the pacemaker in the right atrium during stimulation of the vagus nerve in the dog].

The heart rate and intraatrial latencies between epicardial electrograms from three sites of the right atrium have been studied during vagal stimulation in open-chest dogs. It has been shown that alterations of latencies started at a certain cardiac cycle length irrespective of pacing frequency. A transitional process of changes from a steady latency value in the control to another steady value during vagal stimulation has been observed.

[Optimization of the shape of implantable electrocardiostimulators].

The deficiencies of current electrocardiostimulation equipment are being discussed on the basis of analysis of cases with the device implantation. The authors propose changing the shape of the electrocardiostimulator so, that the frame of the device were surrounded by soft tissue.

[Structure of the tissue adjacent to the electrode in the case of an extremely low threshold of cardial electrostimulation].

The authors present the data of the histological structure of the dog heart tissue adjacent to the electrode tip following a ten-month period of electrical stimulation by means of an implanted graphited porous endocardial electrode and a pacemaker of the alternating polarity. The reason for performing such an histological investigation was an extremely low chronic threshold of heart electrostimulation, amounting to 0.35 V with the stimulus duration 1 ms.

[Use of differential methods for analyzing electrocardiograms in the diagnosis of supraventricular arrhythmia].

Differential-gain ECG (DG-ECG) recordings were made to investigate the mechanism of tachyarrhythmias. The study comprised experimental and clinical series. Experimental findings demonstrated two types (local and circulatory) of vulnerability manifested during induced tachyarrhythmia.

[Decrease in the electrostimulation threshold of the heart by saturating the electrode with glucocorticoids].

A pacing electrode with a porous surface saturated with glucocorticoids has been designed in order to diminish the pacing threshold of the heart. The data obtained in animal studies show that saturation of the electrode with dexamethasone before implantation significantly reduces the pacing threshold.

[Classification of implantable electrodes intended for constant electrostimulation of the heart].

The analysis is given of the currently used classifications for implantable electrodes with special reference to their disadvantages. Since manufacturers produce a great variety of electrode models with the intrinsic codes, certain difficulties are involved when decoding. So, the new, unique seven-alphabetic coding is proposed that may find extensive application.