• Reflex mechanisms affecting the coronary circulation have been postulated and described as participating in the profound fall in blood pressure frequently attending cardiogenic shock following acute coxxmary occlusion. The reflex mechanisms suggested as being responsible for potentiating the cause of sudden death in coronary artery disease are: (1) an intercoronary reflex, which is believed t...

Previous studies showed that the cardiac response of the baroreceptor reflex (bradycardia) is inhibited during the defense reaction evoked by direct electrical or chemical stimulation of the periaqueductal gray (dPAG) in the rat. Whether central serotonin and nucleus tractus solitarius (NTS) serotonin(3) (5-HT(3)) receptors might participate in this inhibition was investigated in urethane-anest...

Cardiac arrest caused by startling stimuli, such as visual and vibration stimuli, has been reported in some animals and could be considered as an extraordinary case of bradycardia and defined as reversible missed heart beats. Variability of the heart rate is established as a balance between an autonomic system, namely cholinergic vagus inhibition, and excitatory adrenergic stimulation of neural...

• Reflex mechanisms affecting the coronary circulation have been postulated and described as participating in the profound fall in blood pressure frequently attending cardiogenic shock following acute coxxmary occlusion. The reflex mechanisms suggested as being responsible for potentiating the cause of sudden death in coronary artery disease are: (1) an intercoronary reflex, which is believed t...

H eart transplantation (HTx) surgically interrupts the parasympathetic vagal neurons and the intrinsic postganglionic sympathetic nerve fibers traveling from the stellate ganglia to the myocardium, causing axonal Wallerian degeneration and thus extrinsic cardiac denervation. Cardiac denervation causes loss of afferent nerves in the myocardium, which is hypothesized to impair the reflex response...