[Change in the thresholds of development of ventricular arrhythmias after stimulation of negative emotiogenic...

The dynamics of changes in the thresholds of the origin of ventricular extrasystole, paroxysmal ventricular tachysystole and ventricular fibrillation in long-term stimulation of the ventromedial hypothalamic nucleus were studied in experiments on rabbits. It was found that myocardial resistance to the development of arrhythmias depended on the manifestation of the sympathetico-parasympathic interaction on the heart. In predominance of parasympathetic effects on the heart during hypothalamic stimulation, the threshold of the origin of arrhythmia increased by 40% for ventricular extrasystole, by 38% for paroxysmal ventricular tachysystole and by more than 36% for ventricular fibrillation. In predominance of sympathetic effects during stimulation of negative emotiogenic hypothalamic centers, the threshold of arrhythmia origin decreased by 45% for ventricular extrasystole, by 32% for paroxysmal ventricular tachysystole and by 24% for ventricular fibrillation.