The in-ear region as a novel anatomical site for ECG signal detection: validation study on healthy volunteers.

PURPOSE: Early detection of cardiac arrhythmias is a major opportunity for mobile health, as wearable devices nowadays available can detect single-lead electrocardiogram (ECG). The study aims to validate the in-ear region as a new anatomical site for ECG signal detection and looks towards designing innovative ECG wearable devices. METHODS: We performed ECG using KardiaMobile device (AliveCor®) on 35 healthy volunteers. First, ECG was detected by standard modality using both hands. Then, ECG was detected using the left in-ear region instead of the right hand. All the recorded ECGs were analyzed by the device and by two cardiologists in blind testing. RESULTS: We successfully collected 70 ECGs performed on 35 volunteers (male 54%, age 39.1 ± 10.7 years; BMI 22.9 ± 2.89 kg/m2) with no differences observed by KardiaMobile in ECG reports detected in the two different modalities. All the ECGs were reported as normal by the device and the two cardiologists. Moreover, linear regression analysis showed good correlation between the amplitude (mV) of P (r = 0.76; r2 = 0.57; p < 0.0001) and QRS waves (r = 0.81; r2 = 0.65; p < 0.0001), the intervals (ms) of PR (r = 0.91; r2 = 0.83; p < 0.0001; LOA - 0.60-0.41; CC = 0.91), QRS (r = 0.78; r2 = 0.61; p < 0.0001; LOA - 0.49-0.43; CC = 0.78), QT (r = 0.85; r2 = 0.71; p < 0.0001; LOA - 1.31-1.20; CC = 0.85), and heart rate (r = 0.94; r2 = 0.89; p < 0.0001; LOA - 7.82-7.76; CC = 0.94) detected in two different modalities. CONCLUSION: The in-ear region is a reliable novel anatomical site for ECG signal detection in normal healthy subjects. Further studies are needed to validate this new ECG detection modality also in case of cardiac arrhythmias and to support the development of new wearable devices.

Ascertainment bias in dementias: a secondary to tertiary centre analysis in Central Italy and conceptual review.

BACKGROUND AND AIMS: Ascertainment bias (AB) indicates a bias of an evaluation centre in estimating the prevalence/incidence of a disease due to the specific expertise of the centre. The aim of our study was to evaluate classification of different types of dementia in new cases appearing in secondary and tertiary centres, in order to evidence possible occurrence of AB in the various (secondary to tertiary) dementia centres. METHODS: To assess the mechanism of AB, the rates of new cases of the different forms of dementia reported by different centres were compared. The centres involved in the study were 11 hospital-based centres including a tertiary centre, located in the University Department of Clinical Neurology. The tertiary centre is endowed with state-of-the-art diagnostic facilities and its scientific production is prominently focused on dementia with Lewy bodies (DLB) thus suggesting the possible occurrence of a bias. Four main categories of dementia were identified: Alzheimer's disease (AD), DLB, fronto-temporal dementia (FTD), vascular dementia (VaD), with other forms in a category apart. The classification rate of new cases of dementia in the tertiary centre was compared with rates reported by secondary centres and rates of recoding were calculated during a follow-up of 2 years. RESULTS: The study classified 2,042 newly diagnosed cases of dementia in a population of 1,370,000 inhabitants of which 315,000 were older than 65. AD was categorized in 48-52 % of cases, DLB in 25-28 %, FTD in 2-4 % and VaD in 17-28 %. During the 2-year follow-up the diagnosis was re-classified in 40 patients (3 %). The rate of recoding was 5 % in the tertiary centre, 2-8 % in referrals from secondary to tertiary centre, 2-10 % in recodings performed in secondary centres and addressed to tertiary centre. Recoding or percentages of new cases of AD or DLB were not different in the comparison between secondary or between secondary and tertiary centres. FTD and VaD were instead significantly recoded. CONCLUSION: The results of the study suggest that in a homogeneous area, AB is not interfering with diagnosis of AD or DLB.

Techniques for transvenous leads extraction.

The number of implanted cardiac pacing and defibrillating devices is currently increasing, leading to an increasing number of device-related complications, due to either malfunction or infection. Removal of the whole system, including the leads, was proven to be the most effective therapy. At present the importance of transvenous lead extraction is consequently increased. In order to remove pacing and implantable cardioverter defibrillators (ICD) leads, they have to be made free from any binding site from the entry in the vein to the tip. Different techniques, including mechanical dilation, powered dilation and intravascular approaches have been developed over the last years and are currently available. Results reported in the literature show a significant success rate (ranging between 90% and 98% of the leads) and a reduced incidence of serious complications (1% to 3% in different series) in selected centres. The extraction procedures are complex and life-threatening complications may always occur, suggesting the need of trained and experienced operators as well as the availability of a surgical standby. At present indications to removal are restricted to infection or to damage of the leads inducing serious risk for the patients; the availability of a more effective and safe technique will probably spread indications to most of abandoned leads.

Effects of haloperidol and GM1 ganglioside treatment on striatal D2 receptor binding and dopamine turnover.

Previous studies have shown that whereas exogenous GM1 ganglioside co-administration leads to an increase of haloperidol-induced behavioral supersensitivity, GM1 significantly attenuates the behavioral parameters of dopaminergic supersensitivity when administered after abrupt haloperidol withdrawal. In the present study, the effects of GM1 and haloperidol co-administration (5 mg/kg GM1 i.p. and 1 mg/kg haloperidol i.p., twice daily, for 30 days) as well as the effects of a 3 day treatment with GM1 were investigated in rats withdrawn from haloperidol administration by measuring striatal D2 dopamine receptor binding and dopamine turnover. The results showed that under these two experimental conditions GM1 modified neither the haloperidol-induced striatal D2 dopamine receptor up regulation nor the decrease in dopamine turnover produced by haloperidol withdrawal. These results suggest that the effects of GM1 on behavioral supersensitivity are not related to modifications in dopamine receptor number or affinity and in the synaptic availability of this catecholamine.

[Mid-term clinical study of the effectiveness of and tolerability to simvastatin ++ in dyslipidemic patients]. / Studio clinico a medio termine sull'efficacia e tollerabilità della Simvastatina in pazienti dislipidemici.

The HGM-CoA reductase inhibitors, blaking up intracellular synthesis of cholesterol, support the receptorial captation of cholesterol with a reduction in plasma levels. The simvastatin efficacy was evaluated in 12 patients, mean age 59 +/- 10 years with a primary hypercholesterolemia. All the patients were on a pharmacologic wash out for at least 6 weeks and dietetic treatment (according to their weight and daily needs) for a week. Total cholesterol, HDL-cholesterol and triglycerides plasma levels were taken at time 0. Then a treatment with simvastatin 10 mg/die was begin for 4 weeks and than increased to 20 mg in patients with plasma cholesterol > 200 mg/100 ml at the end of fourth week. In some patients the dose was increased up to 40 mg for the elevated levels of plasma cholesterol at the end of the second month. All the parameters above were controlled monthly for three months. A control was performed at the end of sixth month of treatment. After 4 weeks treatment, simvastatin induced reduction in cholesterol plasma levels (p < 0.005), that continued during the whole time treatment (228 mg/dl at 24 week, p < 0.005 vs basal). The mean dosage of the simvastatin at fourth month was of 25 mg/die. During the treatment an increase of HDL plasma levels was noted, but this increment wasn't statistical significant (40 +/- 7 vs 45 +/- 9 mg/100 ml). No significant impairment of principal metabolic and laboratory parameters were observed during the treatment. These data indicate that simvastatin in small dose induce a reduction in cholesterol plasma levels with a significant increase in HDL without side effects.

Long-term effects of imipramine on striatal dopamine autoreceptor function: involvement of both noradrenergic and serotonergic systems.

1. The effects of apomorphine (APO) administration on DA system activity were assessed by measuring dopamine metabolite levels (HVA) in several circumstances. 2. Pretreatment with IMI reduced the effect of APO on HVA levels. 3. Pretreatments with either IDE or DMI did not reduce the effect of APO on HVA levels. 4. Reductions of either NE and 5-HT levels after DSP4 and pCPA restored the effect of APO after IMI pretreatment.

Behavioural effects of long-term administration of fencamfamine: neurochemical implications.

The repeated effects of fencamfamine administration (10.0 mg/kg, i.p. single dose) were studied in male rats. Fencamfamine treatment increased stereotyped sniffing and decreased rearing behaviour. These changes occurred after 8 days of treatment and remained for 25 days. The fencamfamine repeated administration enhanced the homovanillic acid (HVA) level in the tubercullum olfactorium while the same treatment decreased the dihydroxyphenilacetic acid (DOPAC) and HVA striatal levels. The data suggest that long-term fencamfamine administration develops changes in the activity of parts of the DA systems which might be responsible for tolerance or sensitization to the effects of fencamfamine.

Chronic imipramine administration reduces apomorphine inhibitory effects.

Changes in activity of dopaminergic and serotonergic systems were assessed after acute and chronic (14 days) imipramine (10 mg/kg) administration in mice. For this purpose, biochemical and behavioural tests were performed at different intervals of time after withdrawal of treatment. Brain levels of 5-hydroxytryptamine, 5-hydroxyindoleacetic acid, homovanillic acid and 3,4-dihydroxyphenylacetic acid were assayed by a fluorometric method. Locomotion and stationary behaviour were investigated in the open-field test. The results of the experiments suggest that chronic imipramine reduces the inhibitory effects of apomorphine upon the dopaminergic system.

Striatal dopamine receptor sensitivity after subchronic fencamfamine in the rat.

Dopamine (DA) receptor sensitivity was assessed in the rat striatal system following subchronic treatment with fencamfamine or saline for 7 days (10 mg/kg i.p.). Seventy-two hours after the last injection the stereotyped behaviour and general activity induced by apomorphine or saline were evaluated. Apomorphine (2.0 mg/kg s.c.) induced a decrease of the stereotypic response when fencamfamine-pretreated animals were compared to saline-treated ones while apomorphine (0.02 mg/kg s.c.) failed to alter the general activity of animals, treated with fencamfamine or not. In biochemical experiments subchronic fencamfamine did not alter the effects of apomorphine (0.02 mg/kg s.c.) in reducing homovanillic acid (HVA) and dihydroxyphenylacetic acid (DOPAC) striatal levels, when compared to saline. In addition we observed a slight but significant reduction in the total dopamine receptor content in the striatum labelled by [3H]spiroperidol. These findings indicate that subchronic fencamfamine treatment leads to a desensitization of postsynaptic DA receptors in rat striatum.

Differential changes in dopaminergic receptor sensitivity induced by agonist drugs.

Mice were treated acutely or chronically with apomorphine (APO) (0.1 and 1.0 mg/kg) or L-DOPA (150 mg/kg) plus benserazide (50 mg/kg). The decrease of homovanillic acid (HVA) caused by APO was greater in acutely treated animals. After APO or L-DOPA pretreatment the animals received single doses of haloperidol (HALO) (1.5 mg/kg) or saline and were submitted to behavioral and biochemical analysis in order to determine changes in dopaminergic receptor sensitivity. When the acutely and chronically treated groups were compared, we found no difference in the cataleptogenic effect of HALO nor any difference in the effect of HALO in increasing brain HVA levels. The data suggest that chronic treatment with dopaminergic agonists leads to changes in receptor sensitivity for the agonist but not for the antagonist effect.

Lethal effect of the serotonin-xylocaineR association in ganglion-blocked rats.

In rats anestetized with urethane and under ganglionic blockade by hexamethonium (20 mg/kg, i.v.), the i.v. injection of serotonin (60 mug/kg) determined apnea, ECG alterations and a brief hypotensive response which is similar to that as elicited when 5-HT is given to intact rats. During the hypertension which follows that initial response, apnea is still present along with more severe ECG changes. After that, blood pressure falls into a prolonged hypotension, which is invariably accompanied by death. Neither norepinephrine, nor respiratory analeptics (CoramineR, RemeflinF) were able to prevent the fatal outcome. Only artificial respiration was found to be useful in some instances. It was concluded that the association serotonin plus lidocaine becomes lethal when given to ganglion-blocked rate, and this toxic effect can be ascribed mainly to the respiratory depressor activity of the drugs.

Normal values of thyroxine and triiodo-thyronine retention in the rat. Valores normais de tiroxina e retenção de triiodo-tironina em ratos.

The authors report the results from Murphy and Pattee's method 9, 10 1964, 1966 for T4 and those from Hamolsky et al.'s method 5 1957 for percent retention of T3 as applied to the normal rat serum. For that purpose, 32 adult Wistar rats, of both sexes, kept at the laboratory environment and fed with usual diet were used. Blood samples were taken after noon directly from the heart, without anesthesia. The analysis showed a T4 value of 4.20 +/- 0.92 mug/100 ml of serum (both sexes). The percentuals for mean T3 retention values were found to be 87.46 +/- 6.59% (male) and 81.78 +/- 5.22% (female). No statistically significant correlation could be drawn between the body weights and the hormonal findings.