BACKGROUND Patients with congenital long-QT syndrome (LQTS) are susceptible to life-threatening arrhythmias. The sympathetic nervous system may have an important triggering role for cardiovascular events in LQTS. We therefore examined measurements of sympathetic neural traffic in patients with LQTS and matched control subjects. METHODS AND RESULTS Twelve patients with congenital LQTS and 12 h...

OBSTRUCTIVE SLEEP APNEA (OSA) IS CHARACTERIZED BY RECURRENT AIRFLOW CESSATION WITH CYCLIC HYPOXEMIA, HYPERCAPNIAAND TRANSIENT AROUSALS.1 This condition leads to activation of the sympathetic nervous system.2 A number of phenomena resulting from apnea have been shown to contribute to the increase of sympathetic nerve activity (SNA), for instance, chemoreceptor activation by hypoxemia3,4 and hype...

Brain autonomic control is asymmetrical, the left hemisphere affecting predominantly parasympathetic function and the right hemisphere affecting predominantly sympathetic function. It is not known whether the extent of autonomic activation is altered in migraine, although the fact that some migraineurs express parasympathetic features such as facial flushing, lacrimation and rhinorrhoea might s...

The inter-related functions of several systems that evolved hundreds of millions of years ago, the vestibular, sympathetic, and cardiovascular systems, have important clinical implications in modern neurology and neuro-otology. Operating largely out of consciousness, the vestibular system responds to head and body movement in any direction, stabilizes the head and body with regard to gravity in...

Many of the blood vessels of the extremities are under reflex control. Numerous stimuli, such as cooling the body, pain, loud noise, or deep inspiration, produce reflex vasoconstriction. Heating the body causes reflex vasodilatation. The fact that either preor post-ganglionic sympathectomy eliminates these vasoconstrictor and vasodilator responses demonstrates that the sympathetic nerves contai...

Microneurographic measurements of muscle sympathetic nerve activity (SNA) have suggested that, during static exercise, central command is much less important than skeletal muscle afferents in causing sympathetic neural activation. The possibility remains, however, that the sympathetic discharge produced by central command is targeted mainly to tissues other than skeletal muscle. To examine this...