Summary: Purpose: Because several reports have described the relation between epilepsy and cardiac arrhythmias and suggest that changes in autonomic neural control of the heart could be involved in the pathogenesis of sudden unexplained death in patients with epilepsy, the aim of this study was to evaluate cardiac function in patients with temporal lobe epilepsy.Methods: Sixty-five patients with epilepsy were evaluated by simultaneous ambulatory 24-h EEG-ECG monitoring, and in 30 of these, power spectral analysis of relative-risk (RR) variability also was carried out, both in the supine position and in a passive tilt position at 60". The power spectrum of RR variability, the two major spectral components detectable at low frequency (LF) and at high frequency (HF), respectively, and the LF/HF ratio were calculated.Results: By EEG-ECG monitoring, we recorded six partial seizures, and in four cases, discharges were associated with sinus tachycardia. However, interictally the occurrence of ventricular and supraventricular arrhythmias was not different from that in normal subjects. The spectral analysis of RR variability, on the other hand, demonstrated in patients with epilepsy a significant decrease in the total RR variability and in both of its components (LF and HF) in the supine position, and of the LF/HF ratio in orthostatic position.Conclusions: These findings suggest that the spectral analysis of RR variability may detect disorders of autonomic cardiac control in patients with epilepsy, even in the absence of abnormal findings during ECG monitoring. This alteration, which is more severe in cases with right EEG focus, could play a role in the pathogenesis of cardiac arrhythmias. Key Words: Temporal lobe epilepsy-Sudden unexplained death in patients with epilepsy-ECG monitoring-Heart rate variabilityAutonomic disorders.Sudden unexplained death in patients with epilepsy (SUDEP) is a well-recognized phenomenon (l), although its pathogenesis is not yet completely understood. In a recent cohort study (2), the maximal overall incidence of SUDEP observed was 1.35 cases/l,OOO person-years, which was similar to values described in previous studies (3,4). In particular, the incidence of SUDEP is increased in males and is correlated with the number of antiepileptic drugs (AEDs) prescribed and with treatment. with psychotropic drugs. It is also associated with alcohol abuse and slightly with mental retardation.With regard to the pathogenesis of SUDEP, the hypothesis of an acute disturbance of the cardiac rhythm as a possible mechanism is supported by various clinical case reports of patients with temporal lobe epilepsy (5,6) Accepted September 13, 1996. Address correspondence and reprint requests to Dr. L. Mum at Department of Neurosciences, Institute of Neurology, Via Roma, 67, 56126 Pisa, Italy and by the finding that both simple and complex partial seizures (CPSs) are consistently associated with tachycardia (7,s) and rarely with bradycardia (9,lO). On the other hand, certain data obtained interictally provide only par...

Forty-four patients suffering a stroke for the first time were examined within 10 h of the onset of symptoms; the tests performed on their admission to hospital, and thereafter on the third and seventh day, were 24-h Holter EKG with spectral analysis of heart rate variability, evaluation of arterial blood pressure and the levels of catecholamine in the blood and 24-h urine. The dynamic EKG on admission revealed that 31 (70.5%) out of the 44 patients already had arrhythmia. These alterations were observed in 9 (75%) out of 12 haemorrhagic patients with a significant (P < 0.05) prevalence compared to 22 (68.8%) of the 32 ischaemic ones. Arrhythmia showed up in 16 (76.2%) out of 21 cases with right hemisphere lesions and in 12 (63.2%) out of 19 cases of left hemisphere lesions; this difference was also significant (P<0.05). Arrhythmia was still present in 19 (43.2%) patients after 3 days and only in 2 (6.5%) patients after 7 days. The spectral analysis parameters on admission and after 3 days were significantly (P < 0.05) modified in patients with stroke plus arrhythmia, compared to patients with stroke alone and to control subjects, whereas no further differences were observed on the seventh day. Moreover, the percentage of patients with arterial hypertension and high levels of catecholamine greatly decreased from the third day onwards. A transient autonomic nervous system imbalance with prevalent sympathetic activity may justify this cardiovascular impairment during the hyperacute phase of stroke.

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Passive smoking has both short-term and long-term vascular effects. It is not clear whether impairment of endothelial function reflects the acute effects of passive smoke exposure or the chronic effects. The purpose of this study was to assess the hypothesis that short-term exposure to passive smoke impairs endothelium-dependent vasodilation in healthy nonsmokers. Eighteen healthy young never smokers (12 men, 6 women) 21 to 55 years old (mean +/- SD: 34 +/-9 years) underwent ultrasonography measuring baseline brachial-artery diameter and brachial-artery diameter during hyperemia and after sublingual administration of nitroglycerin, twice: in a smoke-free environment, and then in the same environment polluted by 30 to 35 ppm carbon monoxide. Each subject served as his/her control. Carboxyhemoglobin was measured in blood samples of subjects tested. Mean value of carboxyhemoglobin was 0.6 +/-0.5% in a smoke-free environment and 1.4 +/- 0.5% in a smoking environment (p <0.02). Mean values of flow-mediated dilation (FMD) were 12.6% +/- 7.8% in a smoke-free environment versus 6.8 +/- 7.8% in a smoking environment (p <0.01). On the contrary, nitroglycerin-induced vasodilation did not show any statistical difference (21 +/- 9.8% versus 23 +/-1.4%). Finally, the increase of carboxyhemoglobin was related statistically to the impairment of flow-mediated dilation (r = 0.51; p <0.002). Passive smoking impaired flow-mediated vasodilation in healthy never smokers in a smoking environment. The impairment was strongly related to carboxyhemoglobin level.

Among patients with hypertrophic cardiomyopathy, only those with outflow tract obstruction show spectral signs of altered autonomic cardiac control. Within this group, the autonomic dysfunction appears to be correlated to myocardial hypertrophy rather than to left ventricular outflow tract obstruction.