Status epilepticus produces chronic alterations in cardiac sympathovagal balance.
OBJECTIVE
Status epilepticus (SE) activates the autonomic nervous system, increasing sympathetic nervous system control of cardiac function during seizure activity. However, lasting effects of SE on autonomic regulation of the heart, which may contribute to mortality following seizure activity, are unknown. Therefore, autonomic control of cardiac function was assessed following SE.


METHODS
Using Sprague-Dawley rats after 1-2 weeks of recovery from lithium-pilocarpine-induced SE or control procedures, we tested overall sympathovagal control of the heart, the individual contributions of the sympathetic and parasympathetic components of the autonomic nervous system, and baroreflex sensitivity.


RESULTS
SE induced a chronic shift in sympathovagal balance toward sympathetic dominance resulting from decreased parasympathetic activity. Baroreflex sensitivity to increased blood pressure was also decreased, likely resulting from diminished vagal activation.


CONCLUSIONS
Chronic alterations in autonomic regulation of cardiac function, characterized by increased sympathetic dominance, occur following SE and likely contribute to subsequent increased cardiac risk and mortality.
Metcalf
Cameron S
CS
Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, Utah, USA.
Radwanski
Przemyslaw B
PB
Bealer
Steven L
SL
D000704:Analysis of Variance; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D017704:Baroreflex / Q000187:drug effects / Q000502:physiology; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology*; D004195:Disease Models, Animal; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology*; D018021:Lithium Chloride; D008297:Male; D018727:Muscarinic Antagonists / Q000494:pharmacology; D010862:Pilocarpine; D051381:Rats; D017207:Rats, Sprague-Dawley; D013226:Status Epilepticus / Q000139:chemically induced / Q000503:physiopathology*; D013564:Sympathetic Nervous System / Q000187:drug effects / Q000503:physiopathology*; D013997:Time Factors; D014630:Vagus Nerve / Q000502:physiology*
D018727:Muscarinic Antagonists; D010862:Pilocarpine; D001285:Atropine; D018021:Lithium Chloride