Biomedical subjects
Publications and source records attributed to Yu R Sheikh-Zade.
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.
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.
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.