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Biomedical subjects

I L Cherednik

Publications and source records attributed to I L Cherednik.

At least 19 recordsLinked to original sources

[The sino-atrial node as an indicator of oscillatory processes in the cardiovascular system].

The spectrogram of heart rate in denervated (vagotomy + propranolol) and artificially ventilated cats always contains the true respiratory peak and 1-3 resonance ones pacing at intervals equivalent to frequency of breathing. Hypothermic decrease of heart rate periodically draws the splitting of respiratory peaks and generation of supplementary rate-dependent peaks reflecting the interference of heart and breathing rhythms. The functional base for detection of mentioned peaks is myogenic reaction of sino-atrial node to its extension by fluctuations of venous inflow.

Animals↗

A method for evaluation of conduction anesthesia.

We propose a new method for evaluation of conduction anesthesia in animals: by the degree of prolongation of cardiac cycle during vagus nerve stimulation by solitary electric discharges synchronous to the dominant ECG wave, proximally from the site of anesthetic application on the nerve.

Anesthesia, Conduction↗

Structural analysis of heart rhythm spectrogram in narcotized cats.

Eight types of peaks were revealed in the cardiac rhythm spectrum during acute experiments on vagotomized cats. Some peaks had no physiological nature and resulted from specificity of ECG processing by Fourier analysis, while others reflected myogenic reaction of the sinoatrial node (length-dependence of automaticity) to changes in venous return caused by respiratory-induced and other variations of the blood flow in the cardiovascular system.

Animals↗

Sympathetic modulation of vagal chronotropic and arrhythmogenic influences on the heart.

In acute experiments on cats, stimulation of the caudal cardiac nerve inhibited tonic and synchronizing components of the vagal chronotropic effects and suppressed arrhythmogenic effect of vagal stimulation. By contrast, stimulation of ansa subclavia potentiated the effects of vagal stimulation. A novel model of vagosympathetic interactions in the heart of mammals is proposed.

Animals↗

Atrial fibrillation: a new explanation of the old phenomenon.

We propose a new mechanism of atrial fibrillation basing on the results of 30 series of acute experiments on anesthetized cats. In brief, combination of two or more arrhythmogenic factors shortens the interval between the inward and outward ionic currents in cardiomyocytes to a critical value. Under these conditions repolarization of cardiomyocyte membrane reaches the excitation threshold before complete inactivation of the depolarizing currents. This inevitably results in autoexcitation of myocytes (or extrasystole), that in turn promotes repolarization. Once occurred, autoexcitation turns into self-triggering activity resembling tachyarrhythmia paroxysm.

Animals↗

Peculiarities of cardiotropic effect of aconitine.

In experiments on anesthetized cats, aconitine produced direct arrhythmogenic and cardiotoxic effects on the myocardium combined with indirect cardiotropic effects mediated via activation of extracardial nerves. Aconitine demonstrated pronounced cholinolytic properties and blocked vagal arrhythmogenic effect.

Aconitine↗