Effect of stress induced by electrical stimulation of the hypothalamus on the electrical stability of the heart in rabbits.

The influence of stress on cardiac electrical stability (CES) and chaotic dynamics of the electrical activity of the heart was studied in acute and chronic experiments in rabbits. Stress was caused by 2-3 h daily immobilization of the animals with electrical stimulation of emotiogenic centers of the hypothalamus through implanted electrodes. CES was estimated by the thresholds for ventricular arrhythmia: paroxysmal ventricular tachycardia, repeated ventricular extrasystoles and ventricular fibrillation (VF).