ABSTRACT
Sudden unexpected death in epilepsy (SUDEP) accounts for nearly 17% of premature deaths among individuals with this condition (Lathers et al. 2008). Witnessed cases indicate that death is contemporaneous with seizure activity (Langan et al. 2005; Tomson
43.1 Scope of the Problem and General Features 693 43.2 Importance of Neurocardiac Interactions in Triggering Life-reatening
Arrhythmias 694 43.3 Neurocircuitry of Cardiac Rhythm Control 696 43.4 Autonomic Mechanisms in Arrhythmogenesis 697
43.4.1 Adrenergic Inuences 697 43.4.2 Alpha-Adrenergic Receptors 699 43.4.3 Sympathetic-Parasympathetic Interactions 699 43.4.4 Baroreexes and Arrhythmias 700
43.5 Behavioral Stress and Arrhythmias 700 43.6 Ambulatory Electrocardiogram-Based Tools for Evaluation of Autonomic
Function 701 43.7 Ambulatory Electrocardiogram-Based T-Wave Alternans to Assess Cardiac
Electrical Instability and Risk for Sudden Cardiac Death 702 43.8 Clinical Evidence of Ambulatory Electrocardiogram-Based T-Wave
Alternans for Prediction of Sudden Cardiac Death 703 43.9 Update on Vagus Nerve Stimulation in Epilepsy 705
43.10 Conclusions and Implications 705 References 706
et al. 2005; Kloster and Engelskjøn 1999). Cardiac dysfunction, primarily in the form of enhanced arrhythmia susceptibility, has been implicated as a critical factor (Opherk et al. 2002; Opeskin et al. 2000; Ryvlin et al. 2006). Whereas decreases in heart rate can occur during epileptic seizures, pronounced sinus tachycardia is the most common electrocardiographic abnormality. Other relatively severe cardiac rhythm, conduction, and repolarization abnormalities have been reported in association with seizures, including bradycardia, asystole, bundle-branch block, ST-segment changes indicative of myocardial ischemia, and T-wave inversion (Opherk et al. 2002; Opeskin et al. 2000; Nei et al. 2004; Tigaran et al. 2003; Jallon et al. 2004). When these abnormalities occur, the length of the seizure is typically prolonged (Zijlmans et al. 2002). e occurrence of bradycardia and asystole in some cases (Rugg-Gunn et al. 2004; Rocamora et al. 2003; Ryvlin et al. 2006) may reect the indirect inuences of seizure-related respiratory disturbances and hypoxia (Lathers et al. 2008) with prone position during sleep a possible factor (Kloster and Engelskjøn 1999).
