Abnormal Cardiac Repolarization After Seizure Episodes in Structural Brain Diseases: Cardiac Manifestation of Electrical Remodeling in the Brain?

Abstract

Background Abnormal cardiac repolarization is observed in patients with epilepsy and can be associated with sudden death. We investigated whether structural brain abnormalities are correlated with abnormal cardiac repolarizations in patients with seizure or epilepsy. Methods and Results We retrospectively analyzed and compared 12-lead ECG parameters following seizures between patients with and without structural brain abnormalities. A total of 96 patients were included: 33 women (17 with and 16 without brain abnormality) and 63 men (44 with and 19 without brain abnormality). Brain abnormalities included past stroke, chronic hematoma, remote bleeding, tumor, trauma, and postsurgical state. ECG parameters were comparable for heart rate, PR interval, and QRS duration between groups. In contrast, corrected QT intervals evaluated by Fridericia, Framingham, and Bazett formulas were prolonged in patients with brain abnormality compared with those without (women: Fridericia [normal versus abnormal], 397.4±32.7 versus 470.9±48.9; P=0.002; Framingham, 351.0±40.1 versus 406.2±46.1; P=0.002; Bazett, 423.8±38.3 versus 507.7±56.6; P<0.0001; men: Fridericia, 403.8±30.4 versus 471.0±47.1; P<0.0001; Framingham, 342.7±36.4 versus 409.4±45.8; P<0.0001; Bazett, 439.3±38.6 versus 506.2±56.8; P<0.0001). QT dispersion and T_peak-T_end intervals were comparable between groups. We also observed abnormal ST-segment elevation in 5 patients. Importantly, no patients showed fatal arrhythmias during or after seizures. Conclusions Our study demonstrated that brain abnormalities can be associated with abnormal cardiac repolarization after seizures, which might be a manifestation of electrophysiological remodeling in the brain.

Keywords: QT prolongation; ST‐segment elevation; seizure; sudden death.

Figure 1. Representative ECG traces following seizure episodes.

A, ECG traces from a 44‐year‐old female patient (upper panel) and a 37‐year‐old female patient (lower panel) without structural brain abnormality. The lead showing the longest QT interval was selected for each patient. The black bar indicates 400 ms. The average values of 2 measurements by 2 examiners were shown for RR and QT intervals. B, ECG traces from a 76‐year‐old female patient with brain abnormality (upper panel) and an 83‐year‐old female patient with cerebral infarction (lower panel). C, ECG traces from a 49‐year‐old male patient (upper panel) and a 48‐year‐old male patient (lower panel) without brain abnormality. D, ECG traces from a 73‐year‐old male patient with chronic subdural hematoma (upper panel) and a 48‐year‐old male patient who had surgery for brain tumor (lower panel).

Figure 2. Comparison of postictal ECG traces with follow‐up ECG traces.

A, ECG traces obtained after seizure episodes and follow‐up ECG traces in 3 patients without brain abnormality. The lead showing the longest QT interval was selected for each patient. The black bar indicates 400 ms. The average values of 2 measurement (2 personnel) were shown for RR and QT intervals. B, ECG traces obtained after seizure episodes and follow‐up ECG traces in 3 patients with brain abnormality: brain tumor surgery (upper panel); brain trauma (mid panel); and metastatic brain tumor (lower panel). QTc intervals (Fridericia): initial, 443, 485, 407 ms vs follow‐up, 400, 438, 394 ms. Note that the follow‐up time varied depending on the patient. F indicates female; and M, male.

Figure 3. ECG traces and 12‐lead ECG after seizure attacks.

Precordial leads obtained from 4 patients showing ST‐segment elevation (A through D). A 12‐lead ECG obtained a patient who died suddenly 2 days after discharge. Black bars indicate 400 ms. (E). Clinical information is described in the text. F indicates female; and M, male.