[Inpatient cardiac defibrillation: efficacy of bipolar sinusoidal impulse]. / Vnutribol'nichnaia defibrilliatsiia zheludochkov serdtsa: éffektivnost' bipoliarnogo sinusoidal'nogo impul'sa.

Efficacy of external defibrillation of the heart with low energy (

[Optimisation of electroimpulse therapy of life threatening arrhythmia in patients with ischemic heart disease]. / Sposob optimizatsii élektroimpul'snoi terapii zhizneopasnykh aritmii u bol'nykh s ishemicheskoi bolezn'iu serdtsa.

The thorax impedance (TI) was measured in 230 patients with atrial and ventricular rhythm impairments according to L. Geddes et al. Gauze napkins moistened in physiological solution (PS) and in 7% hypertonic solution NaCl (HS) were used as contact material. The electrode diameter was approx. 12 cm. The use of HS was shown to bring about a TI decrease by 21% (from 77.0 +/- 0.9 to 61.0 +/- 1.0 ohm) versus the former. A high TI (60-146 ohm) was registered in 41 of 230 patients for whom PS was applied. HS ensures a TI decrease by 17% (to 79-128 ohm). Forty-six patients with atrial fibrillation underwent the electropulse therapy (EPT). Low-energy bipolar discharges (< or = 65 J.) were effective in 31 (67.5%) of 46 patients, < or = 65 J. Discharges were more effective in patients with TI < or = 60 ohm versus patients with TI > 60 ohm (76.7 and 52%, respectively, p = 0.04). With HS the efficiency of bipolar < or = 90 J. discharges reached 83% (38/46). According to estimates, at least one more 100-115 J. discharge would be needed for 7 patients to ensure the similar EPT efficiency with PS.

[Analysis of ECG in ventricular fibrillation in man and animals based on chaos theory]. / Analiz EKG pri fibrilliatsii zheludochkov u cheloveka i zhivotnykh na osnove teorii khaosa.

The methods of the chaos theory were used to estimate the degree of irregularity of ventricular fibrillation in human and experimental animals. To verify the hypothesis that the degree of chaos depends on the species of the living organisms, the parameters characterizing the degrees of irregularity of ventricular fibrillation were estimated and compared. The comparative analysis was performed using 32 fragments of electrocardiographic records from five patients with sudden ventricular fibrillation bouts and 215 episodes of induced fibrillation in 17 animals. It was shown that fibrillation in human and animals has a different degree of regularity and different values of the chaotic component. The highest values of chaos were recorded in dogs, the lowest degree of chaos was observed in human. Rabbits and rats are intermediate, between dogs and humans. The fractuality of the structure-function organization of myocardium is discussed.

[The shape of high-voltage impulse and the effect of defibrillation]. / Vliianie formy vysokovol'tnogo impul'sa na éffekt defibriliatsii.

The paper discusses how to choose the optimum shape of a pulse for electric defibrillation of the heart. The authors' data are given on the values of an induced field in the contracting myocardial structure when a defibrillator evokes pulses. Mono- and bipolar pulse-induced changes of the transmembranous potential on the hyper- and depolarized sides of a cell are calculated. Mechanisms of defibrillation in the use of pulses of different shapes are considered.

[Transthoracic defibrillation of cardiac ventricles: effects of novocainamide on effectiveness of an electric impulse of bipolar sinusoidal shape]. / Transtorakal'naia defibrilliatsiia zheludochkov serdtsa: vliianie novokainamida na éffectivnost' élektricheskogo impul'sa bipoliarnoi sinusoidal'noi formy.

Experiments on nembutal-narcotized dogs were made to study dose effects of novocainamide (10-65 mg/kg) on threshold values of transthoracic defibrillation current of bipolar sinusoidal shape. Reversible dose-dependent increase of the threshold of ventricular defibrillation by 21%, on the average, was achieved only after novocainamide lowering of arterial pressure by 15-35 mm Hg. Coefficient of correlation between the drug dose and intensity of the efficient current made up 0.72.

[Segmental contractile activity of the left ventricle in life threatening arrhythmia]. / Segmentarnaia sokratitel'naia aktivnost' levogo zheludochka pri zhizneopasnykh aritmiiakh.

Intramural pressure (IMP) in the middle segment of the left ventricle and in the apex under ventricular extrasystoles was measured in experiments on the hearts of narcotized dogs. Early extrasystoles caused greater lowering of IMP and blood ejection. Bigeminia was associated with segmental and transmural nonuniformities of IMP which may be due to additional dragging effects in the myocardium. Magnitude of cardiac ejection under extrasystoles depends on nonuniform contractions of the segments of the left ventricle.

[Transthoracic ventricular defibrillation: effectiveness of bipolar sinusoidal impulse]. / Transtorakal'naia defibrilliatsiia zheludochkov serdtsa: éffektivnost' bipoliarnogo sinusoidal'nogo impul'sa.

The efficacy of low-energy bipolar pulse is studied in 41 patients with sudden heart arrest caused by ventricular fibrillation (VF). Maximal energy of effective charges during defibrillation of patients with or without acute myocardial infarction and primary VF (30 episodes) was only 90 J x 1-2. For eliminating secondary VF (76 episodes), maximal energy of 165-195 J x 1-5 was needed in only 25% patients. Total efficacy of charges of at least 115 J x 1-2 in patients with primary and secondary VF was 87%. The results indicate a high efficacy of low-energy bipolar sinusoidal charges for elimination of VF in patients with acute myocardial infarction and other forms of coronary disease.

[Transthoracic defibrillation of heart ventricles: effectiveness and safety of mono- and bipolar impulses]. / Transtorakal'naia defibrilliatsiia zheludochkov serdtsa: éffektivnost' i bezopasnost' mono- i bipoliarnogo impul'sov.

Two widely used forms of defibrillating pulse were compared in experiments on narcotized dogs weighing 7 to 39 kg. Gurvich quasisinusoidal bipolar pulse was found to be much more effective than Edmark's critically dampered sinusoidal monopolar pulse. A close direct correlation between body weight (m) and threshold values of current (I) was found characteristic of both pulse forms. The following regression equations were derived: I = 0.32.m + 3.78 for a bipolar pulse and I = 0.76.m + 2.5 for monopolar one. A bipolar noncardiosynchronized pulse during exposure of an intact heart was found to induce a far less in duration reversible ventricular asystole and a much rarer development of fibrillation of cardiac ventricles.

[Effects of bonnecor on transmembrane potentials of cardiomyocytes of the ventricular contractile myocardium of the intact heart and ventricular fibrillation]. / Vliianie bonnekora na transmembrannye potentsialy kardiomiotsitov sokratitel'nogo miokarda zheludochkov intaktnogo serdtsa i fibrilliatsiiu zheludochkov.

The microelectrode technique has shown that bonnecor given in a dose of as many as 2 mg/kg increases the action potential amplitude, but when its dose is increased up to 3 mg/kg, the agent decreases the action potential amplitude of ventricular cardiomyocytes in the guinea-pig, the resting potential remaining steady. Administration of bonnecor prevents ventricular fibrillation after aconitine application and provokes ventricular fibrillation and flutter when the focus of ectopic automatism is formed.

[A comparative evaluation of the efficacy of the traditional combination of high-frequency and intermittent high-frequency artificial ventilation of the lungs in patients with parenchymatous acute respiratory insufficiency]. / Sravnitel'naia otsenka éffektivnosti traditsionnoi sochetannoi vysokochastotnoi i preryvistoi vysokochastotnoi iskusstvennoi ventiliatsii legkikh u bol'nykh s parenkhimatoznoi ostroi dykhatel'noi nedostatochnost'iu.

Conventional controlled lung ventilation (CLV) with positive end expiratory pressure (PEEP) (Con CLV), combined high-frequency CLV (Com HF CLV) and intermittent high-frequency CLV with PEEP (Int HF CLV) have been performed in 43 patients with parenchymatous acute respiratory failure (ARF). It has been established that Int HF CLV significantly increases PaO2 in patients with focal damages of the lung parenchyma and effective compliance (Ceff) > 0.033 l/cm H2O. Com HF CLV increases significantly PaO2 and lung compliance in patients with disseminated lung damages and Ceff < 0.030 l/cm H2O and has marked consequences. Different efficacy of various types of HF CLV under study may be to some extent accounted for by different intraalveolar maximum pressure, which (as it has been shown on the lung model) is higher in Com HF CLV and lower in Con CLV and Int HF CLV.

[Effects of taurine and dipeptide Tyr-Tyr on ventricular defibrillation]. / Vliianie taurina i dipeptida Tyr-Tyr na defibrilliatsiiu zheludochkov serdtsa.

Results of the study of taurine and dipeptide Tyr-Tyr effect on the threshold values of functional lesions of the myocardium and heart defibrillation are reported. The experiments were carried out on 27 narcotized mongrel dogs weighing 12-30 kg. Defibrillation was performed using Lifepak-7 defibrillator (USA). Lesion threshold (LT), defibrillation threshold (DT) and electrotherapeutic index (ETI) as a LT:DT ratio were determined. In 14 experiments (control group) these parameters were evaluated during 3 h. In group 1 (6 experiments) taurine (100 mg/kg) was infused intravenously by the end of the 1st hour, in group 2--Tyr-Tyr (25 mg/kg). It was shown that infusion of taurine did not have a noticeable effect of the LT, DT and ETI values. Infusion of Tyr-Tyr resulted in an increase in LT and DT. The possibility to use dipeptide Tyr-Tyr in the complex of measures aimed at ceasing ventricular fibrillation is discussed.

[Analysis of late potentials of the heart ventricles in patients with respiratory failure]. / Analiz pozdnikh potentsialov zheludochkov serdtsa u bol'nykh s dykhatel'noi nedostatochnost'iu.

The ECG signal was studied by the method of Simson in 43 patients with the clinical pattern of respiratory failure of different genesis with the aim in view to detect signs of late ventricular potentials (LVP) in the QRS vector and in separate orthogonal leads X, Y and Z. The signal was averaged by 150 complexes. It has been shown that 53% of the patients examined have signs of LVP, their incidence being much higher in critical patients subjected to controlled lung ventilation. Characteristic differences of the LVP signs analysed in leads X, Y and Z have been detected, as compared to the analogous parameters of the control group.

[Role of heart mass in the spontaneous defibrillation process]. / Rol' massy serdtsa v protsesse spontannoi defibrilliatsii.

The duration of periods of the spontaneous reversible fibrillation of heart ventricles of different masses of guinea pigs, rabbits, pigeons and chickens was investigated. It was demonstrated, that a heart mass doesn't play an important role in the process of spontaneous heart ventricles defibrillation. Only the number of strong contacts and the level of the parasympathetic control are determined.