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by Walter de Gruyter • Berlin • New York. DOI 10.1515/JPM.2004.124 .... w5x Voss A, H Malberg, N Wessel, A Schumann, Th Walther, H. Stepan, R Faber: ...
J. Perinat. Med. 32 (2004) 538–540



Copyright  by Walter de Gruyter • Berlin • New York. DOI 10.1515/JPM.2004.124

Changes of blood pressure and heart rate variability precede a grand mal seizure in a pregnant woman

Renaldo Faber1,*, Holger Stepan1, Mathias Baumert2, Andreas Voss2 and Thomas Walther3 Department of Obstetrics and Gynecology, University of Leipzig, Germany 2 Faculty of Medical Engineering, University of Applied Sciences, Jena, Germany 3 Department of Pharmacology, Erasmus Medical Center, The Netherlands 1

Abstract In order to evaluate blood pressure- and heart rate variability as a potent diagnostic tool for different hypertensive pregnancy disorders we started a clinical trial recording these variables in early pregnancies predisposed for preeclampsia. During routine measurements one of the patients experienced a grand mal epileptic seizure. Since the parameters of both heart rate and blood pressure variability were sequentially altered immediately before the seizure, this case report provides an interesting insight into autonomic cardiovascular control in a developing convulsive fit and the pathophysiological generation of a grand mal seizure in pregnancy. Keywords: Blood pressure variability; eclampsia; grand mal seizure; heart rate variability; pregnancy.

Case report Heart rate variability and blood-pressure variability (HRV/ BPV) have been shown to be relevant predictors for the mortality of patients with cardiovascular disorders w1, 6x. Also patients with epilepsy show significant changes in HRV and BPV caused by anticonvulsive drugs or by epilepsy w3, 4x. Our group could show that normal pregnant women exhibit significant alterations in autonomic cardiovascular control in comparison to non-pregnant women w5x. In an ongoing longitudinal study we investigated pregnancies with and without risk factors for preeclampsia (e.g. pathological uterine perfusion) in order to evaluate whether HRV and BPV differ between various hyperten*Corresponding author: Renaldo Faber M.D. Universita¨tsfrauenklinik Philipp-Rosenthalstr. 55 04103 Leipzig/Germany Tel.: q49-341-9723467 Fax.: q49-341-9723669 E-mail: [email protected]

sive disorders in pregnancy w3x. Furthermore, the predictive value of selected variability parameters relevant to preeclampsia was assessed. Pregnant women were monitored for 30 minutes every four weeks, beginning at 20 weeks, using a PORTAPRES non-invasive blood pressure monitor with a sampling frequency of 200 Hz w5x. A 21-year old gravida 1 para 0 suffered from epilepsy due to a fronto-temporal arterio-venous malformation and was treated with carbamazepine and valproate. Variability parameters at the first measurement at 20 weeks were normal (data not shown) and the woman experienced no epileptic seizure during pregnancy. In the 24th week of gestation, during the second monitoring session, the patient developed a grand mal seizure. The generalized tonic-clonic convulsions appeared clinically to be a typical epileptic fit but this could not be confirmed by concomitant EEG. Blood pressure and heart rate were recorded over 12 minutes until the onset of unconsciousness. As described by Voss et al. w5x, the data was analyzed comparative to a 12-minute reference curve recorded from the woman at 20 weeks. Since important abnormalities were obvious (Figure 1, Panel A), we divided the values into 4-minute-intervals in order to detect the beginning of possible changes before the seizure. Both BPV and HRV showed an important increase in the very low frequency band (VLF) at the beginning of monitoring (12 minutes prior to seizure). At this time the low frequency (LF) domain was upregulated with delay, but the high frequency bands remained unchanged. The delayed LF abnormalities are first manifest in the BPV followed by an increase in LF of HRV (Figure 1, Panel B). Since VLF bands mainly reflect sympathetic activity, this part of the autonomic control seems to be important for the evolution of epileptic seizures. The analysis shows for the first time the behavior of HRV and BPV immediately before a grand mal seizure in a pregnant woman. However, we cannot exclude the possibility that the observed convulsions represent only the end of a complex seizure generated from the frontotemporal focus. Recently, reduced HRV and BPV have been reported in non-pregnant patients with epilepsy in the interictal period w4x. However, our patient showed no differences to normal pregnant women during the first measurement. This is in contrast to the documented finding that epilepsy per se, as well as anticonvulsive drugs, has an impact on HRV and BPV w3, 4x. Our case report shows that simple blood pressure and heart rate monitoring with high resolution may allow prediction of a generalized convulsive seizure. Since our

Faber et al., BPV and HRV in grand mal seizure 539

Figure 1 (A) Systolic blood pressure (SBP) and beat-to-beat intervals (BBI) of a pregnant woman 4 weeks (control) and 12 minutes before epileptic seizure. (B) Comparison of blood pressure and heart rate variability (BPV and HRV) between measurements beginning 12 minutes before grand mal seizure (GMS) and 4 weeks before the seizure (con). Frequencies are divided into very low (VLF), low (LF), and high (HF) frequency. 1s1–4 minutes, 2s5–8 minutes, 3s9–12 minutes interval before seizure.

540 Faber et al., BPV and HRV in grand mal seizure

group has shown that different types of hypertensive pregnancy disorders including preeclampsia are characterized by distinct HRV and BPV alterations w2x, it is of great interest to discover how these parameters might change before the onset of an eclamptic fit. We are aware that this method is not clinically applicable for the prediction of a seizure in pregnancy. However, the measured alterations in the autonomic cardiovascular control, particularly in the VLF of HRV and BRV, provide an interesting insight into the pathophysiological generation and development of a grand mal seizure in pregnancy.

References w1x Algra A, JGP Tijssen, JRTC Roelandt, J Pool, J Lubsen: Heart rate variability from 24-hour electrocardiography and the 2year risk for sudden death. Circulation 88 (1993) 180

w2x Faber R, H Stepan, M Baumert, A Voss, T Walter: Analysis of blood pressure waveform – a new method for the classification of hypertensive pregnancy disorder. J Human Hypertens 18 (2004) 135 w3x Persson H, M Ericson, T Tomson: Carbamazepine affects autonomic cardiac control in patients with newly diagnosed epilepsy. Epilepsy Res 57 (2003) 69 w4x Tomson T, M Ericson, C Ihrman, LE Lindblad: Heart rate variability in patients with epilepsy. Epilepsy Res 30 (1998) 77 w5x Voss A, H Malberg, N Wessel, A Schumann, Th Walther, H Stepan, R Faber: Baroreflex sensitivity, heart rate and blood pressure variability in normal pregnancy. Am J Hypertens 13 (2000) 1218 w6x Zuanetti G, JMM Neilson, R Latini, E Santoro, AP Maggioni, DJ Ewing: Prognostic significance of heart rate variability in post-myocardial infarction patients in the fibrinolytic era. Circulation 94 (1996) 432 Received January 29, 2004. Revised June 6, 2004. Accepted June 9, 2004.