Ventricular vulnerability during sympathetic stimulation: role of heart rate and blood pressure.

Sequential pulsing of the normal ventricle of intact dogs with twice threshold stimuli during stellate ganglion stimulation resulted in a 60% incidence of ventricular fibrillation (VF). The occurrence of VF was independent of accompanying changes in heart rate and arterial blood pressure. Reserpine pretreatment prevented the development of VF.