Responses of sympathetic nerves to programmed ventricular stimulation

Responses of sympathetic nerves to programmed ventricular stimulation.

Ventricular arrhythmias generally result in a decrease in arterial pressure and increases in atrial and ventricular filling pressures which would be expected to induce reflex changes in efferent sympathetic nerve activity to the heart and peripheral circulation. Experiments were performed in 14 anesthetized dogs in order to determine whether programmed ventricular stimulation produces changes i...

Localized myocardial responses to stimulation of cardiac sympathetic nerves.

Myocardial contractile force was recorded at three to five positions on the canine heart while progressively more distal portions of the cardiac sympathetic nerves were electrically stimulated. When the electrodes were applied directly to the stellate ganglion or to the ansa subclavia, positive inotropic responses were generally observed on all of the test regions of the heart. However, when mo...

Cardiac responses to sympathetic stimulation.

The cardiac res|x>nses to stimulation of sympathetic nerves to the heart were studied both in thoracotomized and in intact unanesthetized dogs. The changes in heart rate, left ventricular pressure, right and left ventricular dimensions and systemic arterial pressures were recorded. The powerful effects of sympathetic stimulation resemble cardiac responses to exercise more than those following a...

Impaired responses of sympathetic nerves to cardiac receptor stimulation in hypertension.

We recently reported that the vagal cardiopulmonary baroreceptor reflex inhibition of renal nerve traffic is impaired in rabbits with renal hypertension. The purpose of this study was to determine if the locus of the abnormality is mainly in the brain or in the afferent limb of the reflex. Experiments were done in alpha-chloralose-anesthetized rabbits with (n = 10) or without (n = 10) hypertens...

Programmed ventricular stimulation: not dead.