Ictal asystole and ictal syncope: insights into clinical management.
BACKGROUND
Ictal asystole is a rare, serious, and often treatable cause of syncope. There are currently limited data to guide management. Characterization of ictal syncope predictors may aid in the selection of high-risk patients for treatments such as pacemakers.


RESULTS
We searched our epilepsy monitoring unit database from October 2003 to July 2013 for all patients with ictal asystole events. Clinical, electroencephalogram, and ECG data for each of their seizures were examined for their relationships with ictal syncope events. In 10 patients with ictal asystole, we observed 76 clinical seizures with 26 ictal asystole episodes, 15 of which led to syncope. No seizure with asystole duration≤6 s led to syncope, whereas 94% (15/16) of seizures with asystole duration>6 s led to syncope (P=0.02). During ictal asystole events, 4 patients had left temporal seizure onset, 4 patients had right temporal seizure onset, and 2 patients had both. Syncope was more common with left temporal (40%) than with right temporal seizures (10%; P=0.002). Treatment options included antiepileptic drug changes, epilepsy surgery, and pacemaker implantation. Eight patients received pacemakers. During follow-up of 72±95 months, all patients remained syncope free.


CONCLUSIONS
Ictal asystole>6 s is strongly associated with ictal syncope. Ictal syncope is more common in left than in right temporal seizures. A permanent pacemaker should be considered in patients with ictal syncope if they are not considered good candidates for epilepsy surgery.
From the Autonomic Dysfunction Center (M.B., W.D.D., S.R.R.), Departments of Medicine (M.B., D.D., S.R.R.), Pharmacology (D.D., S.R.R.), Neurology (A.A., B.A.-K.), and Biostatistics (D.P., W.D.D.), Vanderbilt University School of Medicine, Nashville, TN; Department of Cardiac Sciences, Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada (S.R.R.).
Michael
M
Bestawros
From the Autonomic Dysfunction Center (M.B., W.D.D., S.R.R.), Departments of Medicine (M.B., D.D., S.R.R.), Pharmacology (D.D., S.R.R.), Neurology (A.A., B.A.-K.), and Biostatistics (D.P., W.D.D.), Vanderbilt University School of Medicine, Nashville, TN; Department of Cardiac Sciences, Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada (S.R.R.).
Dawood
D
Darbar
From the Autonomic Dysfunction Center (M.B., W.D.D., S.R.R.), Departments of Medicine (M.B., D.D., S.R.R.), Pharmacology (D.D., S.R.R.), Neurology (A.A., B.A.-K.), and Biostatistics (D.P., W.D.D.), Vanderbilt University School of Medicine, Nashville, TN; Department of Cardiac Sciences, Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada (S.R.R.).
Amir
A
Arain
From the Autonomic Dysfunction Center (M.B., W.D.D., S.R.R.), Departments of Medicine (M.B., D.D., S.R.R.), Pharmacology (D.D., S.R.R.), Neurology (A.A., B.A.-K.), and Biostatistics (D.P., W.D.D.), Vanderbilt University School of Medicine, Nashville, TN; Department of Cardiac Sciences, Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada (S.R.R.).
Bassel
B
Abou-Khalil
From the Autonomic Dysfunction Center (M.B., W.D.D., S.R.R.), Departments of Medicine (M.B., D.D., S.R.R.), Pharmacology (D.D., S.R.R.), Neurology (A.A., B.A.-K.), and Biostatistics (D.P., W.D.D.), Vanderbilt University School of Medicine, Nashville, TN; Department of Cardiac Sciences, Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada (S.R.R.).
Dale
D
Plummer
From the Autonomic Dysfunction Center (M.B., W.D.D., S.R.R.), Departments of Medicine (M.B., D.D., S.R.R.), Pharmacology (D.D., S.R.R.), Neurology (A.A., B.A.-K.), and Biostatistics (D.P., W.D.D.), Vanderbilt University School of Medicine, Nashville, TN; Department of Cardiac Sciences, Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada (S.R.R.).
William D
WD
Dupont
From the Autonomic Dysfunction Center (M.B., W.D.D., S.R.R.), Departments of Medicine (M.B., D.D., S.R.R.), Pharmacology (D.D., S.R.R.), Neurology (A.A., B.A.-K.), and Biostatistics (D.P., W.D.D.), Vanderbilt University School of Medicine, Nashville, TN; Department of Cardiac Sciences, Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada (S.R.R.). satish.raj@ucalgary.ca.
Satish R
SR
Raj
D000328:Adult; D000927:Anticonvulsants / Q000009:adverse effects / Q000627:therapeutic use*; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects; D018572:Disease-Free Survival; D004562:Electrocardiography; D004569:Electroencephalography; D005260:Female; D006323:Heart Arrest / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000009:adverse effects; D010138:Pacemaker, Artificial; D018579:Patient Selection; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012307:Risk Factors; D012640:Seizures / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D013575:Syncope / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D013997:Time Factors; D016896:Treatment Outcome; D014741:Video Recording
D000927:Anticonvulsants
autonomic nervous system; cerebrovascular circulation; heart arrest; seizures; syncope