Gender-Related Differences in Heart Rate Variability of Epileptic Patients

Abstract

Recently, heart rate variability (HRV) analysis has been used as an indicator of epileptic seizures. As women have a lower sudden, unexpected death in epilepsy risk and greater longevity than men, the authors postulated that there are significant gender-related differences in heart rate dynamics of epileptic patients. The authors analyzed HRV during 5-minute segments of continuous electrocardiogram recording of age-matched populations. The middle-aged epileptic patients included males (n = 12) and females (n = 12), ranging from 41 to 65 years of age. Relatively high-(0.15 Hz-0.40 Hz) and low-frequency (0.01 Hz-0.15 Hz) components of HRV were computed using spectral analysis. Poincaré parameters of each heart rate time series were considered as nonlinear features. The mean heart rate markedly differed between gender groups including both right-and left-sided seizures. High-frequency heart rate power and the low-frequency/high-frequency ratio increased in the pre-ictal phase of both male and female groups (p < .01), but men showed more increase especially in right-sided seizures. The standard deviation ratio, SD2/SD1, of pre-ictal phase was greater in males than females (p < .01). High-frequency spectral power and parasympathetic activity were higher in the female group with both right-and left-sided seizures. Men showed a sudden increase in sympathetic activity in the preictal phase, which might increase the risk of cardiovascular disease in comparison to women. These complementary findings indicate the need to account for gender, as well as localization in HRV analysis.

Pre-ictal heart rate changes: A systematic review and meta-analysis

“…Pre-ictal HRI was found in 623/2957 seizures (21.1%) and it was reported in 14 studies [12,14,21,22,[24][25][26][28][29][30][31][32][33]35,39], while no pre-ictal change was found in five studies [16,19,27,28,34]. The remaining eleven studies did not report the number of seizures with pre-ictal HRI, although they commented on its occurrence and onset time [13,15,17,18,20,23,[36][37][38]40,41]. The median onset time of pre-ictal HRI was 10.7 s prior to seizure onset (IQR 5-60), with one study reporting HR increase from 30 min before [17].…”

“…Thirty studies, enrolling 1110 people living with epilepsy (39.0% female; 38.2% male; 22.8% not reported) and a total of 2957 seizures, assessed the occurrence of pre-ictal HRI. Eighteen included adults [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29], four children only [29][30][31][32][33], and seven both adults and children [34][35][36][37][38][39][40]. The age group was not reported in one study [41].…”

“…The age group was not reported in one study [41]. Fourteen studies included people with different type of focal epilepsy [12][13][14][15][16][17][18][19][20][34][35][36][37]41], 11 TLE [21][22][23][24][25][26][27][28][29][30][31], four a combined sample of focal and generalized epilepsy [32,33,38,39], and one nocturnal frontal lobe epilepsy (NFLE) [40]. Fifteen studies included drug-resistant patients [14][15][16][17][20][21][22]26,28,30,33,35], three non-refractory patients and 12 did not report if patients were drug-resistant or not [12,13,24,25,27,…”

“…In ten studies people continued to receive their AEDs during the recording [15,16,[20][21][22]26,30,31,34,39], while treatment was withdrawn in six studies [21,25,27,29,32,40], and 14 did not report the AEDs status. Twenty-one studies included complex partial seizures (CPS) alone or in combination with other seizure types [15][16][17][18][19][20][21][22][23][26][27][28][29][30][31]33,[35][36][37][38][39][40]. The definition of the pre-ictal and ictal periods was based on seizure onset, identified by clinical [21,25,41], EEG [13,14,16-18,20,23,29-32-34,36-39], or either clinical and EEG manifestations [15,22,27,30,31].…”

“…Although all the studies described the occurrence of IT, only 18 studies clearly reported its frequency, giving a cumulative incidence of 1556/2957 seizures (52.6%) [12][13][14][15]20,22,23,26,29,30,[32][33][34][35][36][37][38][39]. The remaining eight reported the occurrence of IT without specifying the frequency [18,19,21,24,25,27,28,30], while four did not report any quantitative data [16,17,31,41]. The mean ictal HR peak was 116.5 bpm (AE27.0; range 81.2-201.0), demonstrating a mean increase of 56.8% as compared to the baseline HR.…”