Chronic Epilepsy Linked to Higher Risk of Heart Rhythm Irregularities

First-of-its-kind study’s results could help to determine cardiac risk in patients with epilepsy.

More than 3 million people in the United States have epilepsy, a neurological disorder marked by recurrent seizures that may be the result of genetic factors, head trauma or brain infections. Patients with epilepsy are also at nearly three times greater risk of heart attack compared to the general population, and autopsy studies suggest that repeated seizures do cumulative damage to heart muscle. 

In a first-of-its-kind study, a team of physician-scientists at Beth Israel Deaconess Medical Center (BIDMC) in a collaboration between the departments of Neurology and Cardiology compared measures of cardiac health in six patients with long-term, chronic epilepsy to those in six patients newly diagnosed with seizure disorder. The team found that chronic epilepsy was linked to higher levels of cardiac electrical instability, which puts patients at risk for potentially serious heart rhythm irregularities. The findings, recently published in the journal Neurology, shed new light on the relationship between chronic seizures and heart function.

“We did not anticipate the extent of cardiac electrical instability and risk for potential heart rhythm abnormalities in patients with chronic epilepsy,” said neurologist Trudy Pang, MD, MMSc, who is also an Assistant Professor of Neurology at Harvard Medical School. “Our findings could help to improve determination of risk for cardiac arrhythmias in patients with epilepsy – especially in those with poorly controlled seizures and or other vascular risk factors – and to guide medical therapy in patients with epilepsy in both seizure reduction and cardiac protection.” 

In a collaboration between the departments of Neurology and Cardiology, Pang and colleagues investigated whether increased cardiac risk may be the result of seizures and/or long-term use of medications to control epilepsy. The researchers monitored T-wave alternans (TWA) and heart rate variability (HRV) – two established markers of sudden cardiac death – in patients with chronic epilepsy versus patients with newly diagnosed epilepsy. These data were collected via wireless electrocardiographic (EKG) patch electrodes placed on patients’ chests for up to 14 days.  

Analysis of the EKG data revealed that that patients with chronic epilepsy exhibited significantly higher TWA levels, while the newly diagnosed patients’ TWA levels were comparable to healthy adults without an epilepsy diagnosis.  

“In future studies, we hope to determine how long after the initial seizure the heart becomes altered and hence prone to significant rhythm abnormalities,” said Pang. “We also hope to assess the impact of different epilepsy medications on cardiac electrical function. Ultimately, our goal is to develop therapies that lower these cardiac risks in patients with epilepsy.”

Co-authors included; Bruce D. Nearing, PhD, Kaarkuzhali Babu Krishnamurthy, MD, Steven C. Schachter, MD, and, Richard L. Verrier, PhD, all of BIDMC; and Bryan Olin, PhD, of LivaNova PLC, London, UK.

Funding was provided by LivaNova PLC. Drs. Nearing and Verrier are inventors of the Modified Moving Average method of T-wave alternans analysis, which was licensed to GE Healthcare and used in this study.