title: Cardiac dysfunction in rats prone to audiogenic epileptic seizures.
abstract: OBJECTIVE
  Cardiac dysfunction is one of the possible causes of sudden unexpected death in epilepsy (SUDEP). Therefore, the objective of this study was to evaluate cardiac and electrocardiographic parameters in rats with audiogenic epileptic seizures (WAR--Wistar audiogenic rats).
  
  
  METHODS
  In vivo arterial pressure, heart rate (HR), autonomic tone and electrocardiography (ECG) were measured in awake animals in order to examine cardiac function and rhythm. Ex vivo, the Langendorff technique was used to analyze the cardiac function and the severity of reperfusion arrhythmias. In vitro, confocal microscopy was used to evaluate calcium transient parameters of isolated ventricular cardiomyocytes.
  
  
  RESULTS
  In vivo autonomic tone evaluation revealed enhanced sympathetic activity, changes in cardiac function with increased systolic arterial pressure and higher basal HR in WAR. In addition, ECG analysis demonstrated electrical alterations with prolongation of the QT interval and QRS complex in these animals. Ex vivo, we observed a decrease in systolic tone and HR and an increase in the duration of ischemia/reperfusion arrhythmias in WAR. Moreover, intracellular Ca2+ handling analysis revealed an increase in the peak of calcium and calcium transient decay in audiogenic rats. Treatment with atenolol (β1-adrenergic antagonist) normalized the systolic tone, reduced cardiac hypertrophy and the associated increase in the susceptibility to reperfusion arrhythmias observed in WAR.
  
  
  CONCLUSIONS
  We present evidence that chronic disturbances in sympathetic tone in WAR cause increases the risk to life-threatening arrhythmias. Our results support a relationship between seizures, cardiac dysfunction and cardiac arrhythmias, which may contribute to the occurrence of SUDEP.
authors: Department of Educational Development, Federal Institute of Education, Science and Technology of Southeast Minas Gerais-Campus, Barbacena, MG, Brazil. denis.damasceno@ifsudestemg.edu.br
authors: Denis D
authors: DD
authors: Damasceno
authors: Silvia Q
authors: SQ
authors: Savergnini
authors: Enéas R M
authors: ER
authors: Gomes
authors: Silvia
authors: S
authors: Guatimosim
authors: Anderson J
authors: AJ
authors: Ferreira
authors: Maria C
authors: MC
authors: Doretto
authors: Alvair P
authors: AP
authors: Almeida
mesh_terms: D000161:Acoustic Stimulation / Q000009:adverse effects*; D000818:Animals; D001145:Arrhythmias, Cardiac / Q000150:complications / Q000503:physiopathology*; D001794:Blood Pressure / Q000502:physiology; D004562:Electrocardiography / Q000379:methods; D020195:Epilepsy, Reflex / Q000150:complications / Q000503:physiopathology*; D006339:Heart Rate / Q000502:physiology; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D012640:Seizures / Q000150:complications / Q000503:physiopathology*