Early Seizure Detection Based on Cardiac Autonomic Regulation Dynamics

Epilepsy is a neurological disorder that causes changes in the autonomic nervous system. Heart rate variability (HRV) reflects the regulation of cardiac activity and autonomic nervous system tone. The early detection of epileptic seizures could foster the use of new treatment approaches. This study presents a new methodology for the prediction of epileptic seizures using HRV signals. Eigendecomposition of HRV parameter covariance matrices was used to create an input for a support vector machine (SVM)-based classifier. We analyzed clinical data from 12 patients (9 female; 3 male; age 34.5 ± 7.5 years), involving 34 seizures and a total of 55.2 h of interictal electrocardiogram (ECG) recordings. Data from 123.6 h of ECG recordings from healthy subjects were used to test false positive rate per hour (FP/h) in a completely independent data set. Our methodological approach allowed the detection of impending seizures from 5 min to just before the onset of a clinical/electrical seizure with a sensitivity of 94.1%. The FP rate was 0.49 h−1 in the recordings from patients with epilepsy and 0.19 h−1 in the recordings from healthy subjects. Our results suggest that it is feasible to use the dynamics of HRV parameters for the early detection and, potentially, the prediction of epileptic seizures

Influence of cardiac autonomic neuropathy on cardiac repolarisation during incremental adrenaline infusion in type 1 diabetes

Aims/hypothesis We examined the effect of a standardised sympathetic stimulus, incremental adrenaline (epinephrine) infusion on cardiac repolarisation in individuals with type 1 diabetes with normal autonomic function, subclinical autonomic neuropathy and established autonomic neuropathy. Methods Ten individuals with normal autonomic function and baroreceptor sensitivity tests (NAF), seven with subclinical autonomic neuropathy (SAN; normal standard autonomic function tests and abnormal baroreceptor sensitivity tests); and five with established cardiac autonomic neuropathy (CAN; abnormal standard autonomic function and baroreceptor tests) underwent an incremental adrenaline infusion. Saline (0.9% NaCl) was infused for the first hour followed by 0.01 μg kg−1 min−1 and 0.03 μg kg−1 min−1 adrenaline for the second and third hours, respectively, and 0.06 μg kg−1 min−1 for the final 30 min. High resolution ECG monitoring for QTc duration, ventricular repolarisation parameters (T wave amplitude, T wave area symmetry ratio) and blood sampling for potassium and catecholamines was performed every 30 min. Results Baseline heart rate was 68 (95% CI 60, 76) bpm for the NAF group, 73 (59, 87) bpm for the SAN group and 84 (78, 91) bpm for the CAN group. During adrenaline infusion the heart rate increased differently across the groups (p = 0.01). The maximum increase from baseline (95% CI) in the CAN group was 22 (13, 32) bpm compared with 11 (7, 15) bpm in the NAF and 10 (3, 18) bpm in the SAN groups. Baseline QTc was 382 (95% CI 374, 390) ms in the NAF, 378 (363, 393) ms in the SAN and 392 (367, 417) ms in the CAN groups (p = 0.31). QTc in all groups lengthened comparably with adrenaline infusion. The longest QTc was 444 (422, 463) ms (NAF), 422 (402, 437) ms (SAN) and 470 (402, 519) ms (CAN) (p = 0.09). T wave amplitude and T wave symmetry ratio decreased and the maximum decrease occurred earlier, at lower infused adrenaline concentrations in the CAN group compared with NAF and SAN groups. AUC for the symmetry ratio was different across the groups and was lowest in the CAN group (p = 0.04). Plasma adrenaline rose and potassium fell comparably in all groups. Conclusions/interpretation Participants with CAN showed abnormal repolarisation in some measures at lower adrenaline concentrations. This may be due to denervation adrenergic hypersensitivity. Such individuals may be at greater risk of cardiac arrhythmias in response to physiological sympathoadrenal challenges such as stress or hypoglycaemia

Cardiac arrhythmias and electrophysiologic responses during spontaneous hyperglycaemia in adults with type 1 diabetes mellitus

Aim We examined the effect of spontaneous hyperglycaemia in adults with type 1 diabetes mellitus (T1DM) and without history of cardiovascular disease on heart rate variability (HRV), cardiac repolarisation and incidence of cardiac arrhythmias. Methods Thirty-seven individuals with T1DM (age 17-50 years, 19 males, mean duration of diabetes 19.3 SD(9.6) years) underwent 96 hours of simultaneous ambulatory 12-lead Holter ECG and blinded continuous interstitial glucose (IG) monitoring (CGM). HRV, QT interval and cardiac repolarisation were assessed during hyperglycaemia (IG ≥ 15 mmol/l) and compared with matched euglycaemia (IG 5-10 mmol/l) on a different day, separately during the day and night. Rates of arrhythmias were assessed by calculating incidence rate differences. Results Simultaneous ECG and CGM data were recorded for 2395 hours, During daytime hyperglycaemia vs euglycaemia the mean QTc interval duration was 404 SD(21)ms vs 407 SD(20)ms, P = 0.263. T-peak to T-end interval duration corrected for heart rate (TpTendc) shortened (74.8 SD(16.1)ms vs 79.0 SD(14.8)ms, P = 0.033) and T-wave symmetry increased (1.62 SD(0.33) vs 1.50 SD(0.39), P = 0.02). During night-time hyperglycaemia vs euglycaemia, the mean QTc interval duration was 401 SD(26)ms vs 404 SD(27)ms, P = 0.13 and TpTend shortened (62.4 SD(12.0)ms vs 67.1 SD(11.8)ms, P = 0.003). The number of cardiac arrhythmias was low and confined to bradycardia and isolated ectopic beats. A considerable inter-subject and diurnal variability was observed. Conclusions Hyperglycaemia in individuals with T1DM without known cardiovascular disease was not associated with clinically important cardiac arrhythmias

Registro recente de harpia, Harpia harpyja (Linnaeus) (Aves, Accipitridae), na Mata Atlântica da Reserva Natural Vale do Rio Doce, Linhares, Espírito Santo e implicações para a conservação regional da espécie Recent record of harpy eagle, Harpia harpyja (Linnaeus) (Aves, Accipitridae), in Atlantic forest of Vale do Rio Doce Natural Reserve, Linhares, Espírito Santo, Brazil and implications for the regional conservation of the species

A presente comunicação reporta o registro de um macho adulto de harpia, Harpia harpyja (Linnaeus, 1758), na Reserva Natural da Vale do Rio Doce (RNVRD), região norte do Espírito Santo, em agosto de 2005. A análise deste e de registros históricos da espécie nesta reserva indica a presença de uma população residente na região compreendida pela RNVRD e pela Reserva Biológica de Sooretama. Estas duas reservas, contíguas entre si, compreendem cerca de 46250 ha de Floresta Atlântica de baixada (Mata de Tabuleiro), na sua maior parte bem conservada. Além da grande extensão de floresta, a rica e densa fauna de mamíferos presente nestas reservas contribuem para a permanência das harpias na região.<br>The present communication reports an observation occurred in August 2005 of the harpy eagle, Harpia harpyja (Linnaeus, 1758), in the Vale do Rio Doce Natural Reserve (VRDNR), located in northern Espírito Santo state, southeastern Brazil. The analysis of this and past records of the species in this reserve indicates the presence of a resident population in the region encompassed by the VRDNR and the Sooretama Biological Reserve. These two reserves total circa 46,250 ha of lowland Atlantic forest (Tabuleiros forest), which are mostly well preserved. Besides the great extension of forests, the rich and abundant mammal fauna present in these two reserves contribute to the regional permanence of the harpy eagle

PERTINENT - PERindopril-Thrombosis, InflammatioN, endothelial dysfunction and neurohormonal activation trial: A sub-study of the EUROPA study

BACKGROUND: Markers of thrombosis, inflammation, endothelial dysfunction and neurohumoral activation such as fibrinogen, D-dimer, C-reactive protein, von Willebrand factor, tumour necrosis factor-alpha and chromogranin-A are reported to be linked to the increase of cardiovascular risk for atherosclerosis progression and events in patients with cardiovascular diseases. METHODS: EUROPA is a double blind, placebo-controlled trial on 12,231 patients that evaluates the effect of an angiotensin converting enzyme inhibitor--perindopril--on prevention of cardiovascular events in patients with coronary artery disease. PERTINENT is a sub-study of EUROPA that evaluates (a) in Part A (300 patients): the influence of perindopril vs. placebo on fibrinogen, D-dimer, C-reactive protein, von Willebrand factor, tumour necrosis factor-alpha and chromogranin-A. In addition, NOS expression and induction of apoptosis on human umbilical vein endothelial cells and angiotensin converting enzyme levels are also studied; (b) in Part B (about 1200 patients): the predictive role of plasma levels of C-reactive protein and von Willebrand factor on the occurrence of cardiovascular events. To this end, matched case-control analyses are planned (patients with vs. patients without events). STATUS OF PERTINENT: Blood analyses are in progress in four specialised laboratories: (a) Gaubius Laboratory, Leiden, TNO-PG, The Netherlands; (b) University Department of Medicine, Birmingham, UK; (c) University of Pavia, Italy; (d) Fondazione Salvatore Maugeri, Cardiovascular Research Centre, Gussago, Italy. CONCLUSIONS: The PERTINENT sub-study might help elucidating the phenomena contributing to the pathophysiology of cardiovascular events in patients with coronary artery disease and the role of perindopril in such context

Efficacy of perindopril in reduction of cardiovascular events among patients with stable coronary artery disease: randomised, double-blind, placebo-controlled, multicentre trial (the EUROPA study)

BACKGROUND: Treatment with angiotensin-converting-enzyme (ACE) inhibitors reduces the rate of cardiovascular events among patients with left-ventricular dysfunction and those at high risk of such events. We assessed whether the ACE inhibitor perindopril reduced cardiovascular risk in a low-risk population with stable coronary heart disease and no apparent heart failure. METHODS: We recruited patients from October, 1997, to June, 2000. 13655 patients were registered with previous myocardial infarction (64%), angiographic evidence of coronary artery disease (61%), coronary revascularisation (55%), or a positive stress test only (5%). After a run-in period of 4 weeks, in which all patients received perindopril, 12218 patients were randomly assigned perindopril 8 mg once daily (n=6110), or matching placebo (n=6108). The mean follow-up was 4.2 years, and the primary endpoint was cardiovascular death, myocardial infarction, or cardiac arrest. Analysis was by intention to treat. FINDINGS: Mean age of patients was 60 years (SD 9), 85% were male, 92% were taking platelet inhibitors, 62% beta blockers, and 58% lipid-lowering therapy. 603 (10%) placebo and 488 (8%) perindopril patients experienced the primary endpoint, which yields a 20% relative risk reduction (95% CI 9-29, p=0.0003) with perindopril. These benefits were consistent in all predefined subgroups and secondary endpoints. Perindopril was well tolerated. INTERPRETATION: Among patients with stable coronary heart disease without apparent heart failure, perindopril can significantly improve outcome. About 50 patients need to be treated for a period of 4 years to prevent one major cardiovascular event. Treatment with perindopril, on top of other preventive medications, should be considered in all patients with coronary heart disease