Venous obstruction after pacemaker implantation.

Background: Central vein leads are known to predispose to venous obstruction. Although usually asymptomatic, obstruction may render electrode removal difficult. This study aimed at quantifying changes in venous calibers in a prospective fashion by intravenous contrast venography (ICV) before and after pacemaker (PM) or cardioverter-defibrillator implantation.

Time-varying analysis of heart rate variability with kalman smoother algorithm.

A time-varying parametric spectrum estimation method for analyzing nonstationary heart rate variability signals is presented. In the method, the nonstationary signal is first modeled with time-varying autoregressive model and the model parameters are estimated recursively with a Kalman smoother algorithm. The spectrum estimates for each time are then obtained from the estimated model parameters.

Principal Component Regression Approach for QT Variability Estimation.

New algorithm for quantifying the variation in the QT interval of ECG recording is presented. The algorithm is based on the Principal Component Regression where the eigenvectors of the data correlation matrix are calculated. The eigenvectors are then used for calculation of the principal components and one of them is selected to represent the information about T wave variation.

Safety and efficacy of combined antiplatelet-warfarin therapy after coronary stenting.

Aim: The aim of this study was to evaluate the antithrombotic treatment adopted after coronary stenting in patients requiring long-term anticoagulation.

Methods And Results: We analysed retrospectively all consecutive patients on warfarin therapy (n = 239, mean age 70 years, men 74%) who underwent percutaneous coronary intervention (PCI) in 2003-04 in six hospitals. An age- and sex-matched control group with similar disease presentation (unstable or stable symptoms) was selected from the study period.

The impact of polyglycolide membrane on a tendon after surgical rejoining. A histological and histomorphometric analysis in rabbits.

Tissue response to self-reinforced polyglycolide (SR-PGA) membranes surrounding rejoined rabbit tendons was compared with tissue response to nonenveloped rejoined tendons, with special focus on scar formation and SR-PGA membrane biodegradation process. Both hind legs of 20 skeletally mature rabbits were operated on by transecting the plantaris longus tendons and rejoining the ends with sutures. The right side seams were enveloped with bioabsorbable SR-PGA membranes, while the left sides served as noncovered controls.

Titanium and nitride oxide-coated stents and paclitaxel-eluting stents for coronary revascularization in an unselected population.

The aim of this study was to compare clinical outcome of a stainless-steel stent coated with titanium nitride oxide (TITANOX) and a paclitaxel-eluting stent (PES) in routine clinical practice represented by two prospective registries including all patients with de novo coronary artery disease treated exclusively with a TITANOX stent (n = 201) or with a PES (n = 204) between May 2003 and November 2004 (63% of all PCI patients). The primary endpoint of the study was major adverse cardiac events (MACE) at 30 days and 12 months. The TITANOX stent patients were more frequently (p = 0.

Increased fMRI responses during encoding in mild cognitive impairment.

Structural and functional magnetic resonance imaging (fMRI) was performed on 21 healthy elderly controls, 14 subjects with mild cognitive impairment (MCI) and 15 patients with mild Alzheimer's disease (AD) to investigate changes in fMRI activation in relation to underlying structural atrophy. The fMRI paradigm consisted of associative encoding of novel picture-word pairs. Structural analysis of the brain was performed using voxel-based morphometry (VBM) and hippocampal volumetry.

Real world experience with the TITAN(R) stent: a 9-month follow-up report from The Titan PORI Registry.

Aims: The aim of the Titan PORI Registry was to evaluate the safety and efficacy of a stainless steel stent coated with titanium nitride oxide (Titan(R), Hexacath, France) in routine clinical practice.

Methods And Results: We report a prospective single-centre experience in treating patients with the Titan(R) stent. All consecutive patients receiving Titan(R) stent(s) were enrolled.

Time-varying analysis of heart rate variability signals with a Kalman smoother algorithm.

A time-varying parametric spectrum estimation method for analysing non-stationary heart rate variability signals is presented. As a case study, the dynamics of heart rate variability during an orthostatic test is examined. In this method, the non-stationary signal is first modelled with a time-varying autoregressive model and the model parameters are estimated recursively with a Kalman smoother algorithm.

Relationship of P300 single-trial responses with reaction time and preceding stimulus sequence.

Variation of single-trial P300 responses was studied both in relation to reaction times and to the preceding stimulus sequence in an auditory oddball paradigm. Single-trial responses were estimated with the Subspace regularization method that is based on Bayesian estimation and linear modeling. The results of the single-trial method were compared to those of averaging.

Single-trial dynamical estimation of event-related potentials: a Kalman filter-based approach.

A method for single-trial dynamical estimation of event-related potentials (ERPs) is presented. The method is based on recursive Bayesian mean square estimation and the estimators are obtained with a Kalman filtering procedure. We especially focus on the case that previous trials contain prior information of relevance to the trial being analyzed.

High-resolution QRS fiducial point corrections in sparsely sampled ECG recordings.

A model based high-resolution QRS fiducial point correction algorithm, which is suitable for sparsely sampled electrocardiogram (ECG) recordings, is presented. The presented method can be divided into three steps. First, the initial QRS fiducial points are estimated by using ordinary interpolation methods.

Software for advanced HRV analysis.

A computer program for advanced heart rate variability (HRV) analysis is presented. The program calculates all the commonly used time- and frequency-domain measures of HRV as well as the nonlinear Poincaré plot. In frequency-domain analysis parametric and nonparametric spectrum estimates are calculated.

Estimation of nonstationary EEG with Kalman smoother approach: an application to event-related synchronization (ERS).

An adaptive spectrum estimation method for nonstationary electroencephalogram by means of time-varying autoregressive moving average modeling is presented. The time-varying parameter estimation problem is solved by Kalman filtering along with a fixed-interval smoothing procedure. Kalman filter is an optimal filter in the mean square sense and it is a generalization of other adaptive filters such as recursive least squares or least mean square.

Visual processing of coherent rotation in the central visual field: an fMRI study.

Functional magnetic resonance imaging was used to determine the brain areas that process coherent motion. To reduce the activity related to eye-movement planning and self-motion perception, rotation was used as coherent motion and the stimulus was restricted to the central visual field. Coherent rotation relative to incoherent random-dot motion resulted in consistent activation in the superior parietal lobule (SPL), in the lateral occipital gyrus (presumptive kinetic occipital region, KO), and in the fusiform gyrus (FG).

Heart rate variability in acute psychosis.

Heart rate variability (HRV) provides reliable tools to assess the integrity and reactivity of autonomic nervous function. Our aim was to examine HRV in the resting condition and during different mental loads in acute psychosis compared to healthy controls. HRV was measured in 17 first-episode drug-naive patients with psychosis and 21 healthy controls during oddball tasks and while performing the Wisconsin Card Sorting Test.

Single-trial estimation of multichannel evoked-potential measurements.

A method for single-trial estimation of multichannel evoked potentials is presented. The proposed method is based on the regularized least squares scheme. The spatial correlation between the channels is used as additional information in the estimation procedure.

An advanced detrending method with application to HRV analysis.

An advanced, simple to use, detrending method to be used before heart rate variability analysis (HRV) is presented. The method is based on smoothness priors approach and operates like a time-varying finite-impulse response high-pass filter. The effect of the detrending on time- and frequency-domain analysis of HRV is studied.

Endovenous obliteration versus conventional stripping operation in the treatment of primary varicose veins: a randomized controlled trial with comparison of the costs.

Objective: The aim of this randomized study was to compare a new method of endovenous saphenous vein obliteration (Closure System, VNUS Medical Technologies, Inc, Sunnyvale, Calif) with the conventional stripping operation in terms of short-term recovery and costs.

Methods: Twenty-eight selected patients for operative treatment of primary greater saphenous vein tributary varicose veins were randomly assigned to endovenous obliteration (n = 15) or stripping operation (n = 13). Postoperative pain was daily assessed during the 1st week and on the 14th postoperative day.

Analysis of galvanic skin responses with principal components and clustering techniques.

An advanced method for analyzing the patterning of successive galvanic skin responses (GSR) is presented. The proposed method is based on principal component analysis in which the vector containing the measured signal is presented as a weighted sum of orthogonal basis vectors. The method is tested using measurements from 20 healthy controls and 13 psychotic patients.

Loss of time-organized sympathetic skin responses in acute psychosis.

The aim of this study was to differentiate the response pattern characteristics of sympathetic skin responses (SSR) between unmedicated first psychotic subjects and healthy controls. We recorded SSR to novel auditory stimuli in 13 psychotic subjects and in 19 controls. There was no constant delay between a sudden change in the acoustic surroundings and SSR in psychotic subjects, whereas regularly this delay was 1.

Fetal shoulder measurements by fast and ultrafast MRI techniques.

The purpose of this study was to evaluate magnetic resonance imaging (MRI) of fetal shoulder measurements of fetuses with suspected macrosomia. The actual fetal shoulder measurements made immediately after birth were compared with measurements obtained by fast and ultrafast MRI techniques antepartum. Eight singleton diabetic pregnant mothers underwent MRI examination with fast imaging in steady-state precession (TrueFISP) and spin-echo (SE) and gradient-echo (GE) echo-planar (EPI) sequences to show the fetal shoulder width.

A new computational approach for cortical imaging.

Estimation of current or potential distribution on the cortex is used to obtain information about neural sources from the scalp recorded electroencephalogram. If the active sources in the brain are superficial, the estimated field distribution on the cortex also yields information about the active source configuration. In these cases, these methods can be used as source localization methods.