Cardiac arrhythmias in focal epilepsy: A prospective long-term study
Rugg-Gunn FJ, Simister RJ, Squirrell M, Holdright DR, and Duncan JS(2004) Cardiac arrhythmias in focal epilepsy: A prospective long-term study. Lancet 364:9452 2212–9.
Abstract: BACKGROUND: Patients with epilepsy are at risk of sudden unexpected death. Neurogenic cardiac arrhythmias have been postulated as a cause. Electrocardiograms (ECG) can be monitored by use of an implantable loop recorder for up to 18 months. We aimed to determine the frequency of cardiac arrhythmias in patients with refractory focal seizures over an extended period. METHODS: 20 patients received an implantable loop recorder at one hospital in the UK. Devices were programmed to record automatically if bradycardia (<40 beats per min) or tachycardia (>140 beats per min) were detected. Additionally, in the event of a seizure, patients and relatives could initiate ECG recording with an external activator device. Data were analysed at regular intervals and correlated with seizure diaries. FINDINGS: More than 220000 patient-hours were monitored over 24 months, during which ECGs were captured on implantable loop recorders in 377 seizures. One patient withdrew from the study. In 16 patients, median heart rate during habitual seizures exceeded 100 beats per min. Ictal bradycardia (<40 beats per min) was rare, occurring in eight (2.1%) recorded events, in seven patients. Four patients (21%) had bradycardia or periods of asystole with subsequent permanent pacemaker insertion. Three of these four (16% of total) had potentially fatal asystole. INTERPRETATION: Clinical characteristics of patients with peri-ictal cardiac abnormalities are closely similar to those at greatest risk of sudden unexpected death in epilepsy. Asystole might underlie many of these deaths, which would have important implications for the investigation of similar patients and affect present cardiac-pacing policies.
Context
- Prospective study from the UK of EKG abnormalities in patients with epilepsy. 20 patients received implantable recorders programmed to store traces with bradycardia or tachycardia or when activated by patient or seizure witnesses. In 220,000 patient-hours of recording, 377 seizures were captured. Ictal bradycardia of < 40 bpm occurred in 2.1% of recorded events. Asystole was seen in 3 of 16 patients. Comment on the article is in Hirsch and Hauser.