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Biventricular pacing (Biv) and left bundle branch area pacing (LBBAP) are methods of cardiac resynchronization therapy (CRT). Currently, little is known about how they differ in terms of ventricular activation. This study compared ventricular activation patterns in left bundle branch block (LBBB) heart failure patients using an ultra-high-frequency electrocardiography (UHF-ECG). This was a retrospective analysis including 80 CRT patients from two centres. UHF-ECG data were obtained during LBBB, LBBAP, and Biv. Left bundle branch area pacing patients were divided into non-selective left bundle branch pacing (NSLBBP) or left ventricular septal pacing (LVSP) and into groups with V6 R-wave peak times (V6RWPT) < 90 ms and ≥ 90 ms. Calculated parameters were: e-DYS (time difference between the first and last activation in V1–V8 leads) and Vdmean (average of V1–V8 local depolarization durations). In LBBB patients (n = 80) indicated for CRT, spontaneous rhythms were compared with Biv (39) and LBBAP rhythms (64). Although both Biv and LBBAP significantly reduced QRS duration (QRSd) compared with LBBB (from 172 to 148 and 152 ms, respectively, both P < 0.001), the difference between them was not significant (P = 0.2). Left bundle branch area pacing led to shorter e-DYS (24 ms) than Biv (33 ms; P = 0.008) and shorter Vdmean (53 vs. 59 ms; P = 0.003). No differences in QRSd, e-DYS, or Vdmean were found between NSLBBP, LVSP, and LBBAP with paced V6RWPTs < 90 and ≥ 90 ms. Both Biv CRT and LBBAP significantly reduce ventricular dyssynchrony in CRT patients with LBBB. Left bundle branch area pacing is associated with more physiological ventricular activation.

Very high-frequency oscillations (VHFOs, > 500 Hz) are more specific in localizing the epileptogenic zone (EZ) than high-frequency oscillations (HFOs

Background Right ventricular (RV) pacing causes delayed activation of remote ventricular segments. We used the ultrahigh-frequency ECG (UHF-ECG) to describe ventricular depolarization when pacing different RV locations.Methods In 51 patients, temporary pacing was performed at the RV septum (mSp); further subclassified as right ventricular inflow tract (RVIT) and right ventricular outflow tract (RVOT) for septal inflow and outflow positions (below or above the plane of His bundle in right anterior oblique), apex, anterior lateral wall, and at the basal RV septum with nonselective His bundle or RBB capture (nsHBorRBBp). The timings of UHF-ECG electrical activations were quantified as left ventricular lateral wall delay (LVLWd; V8 activation delay) and RV lateral wall delay (RVLWd; V1 activation delay).Results The LVLWd was shortest for nsHBorRBBp (11 ms [95% confidence interval = 5-17]), followed by the RVIT (19 ms [11-26]) and the RVOT (33 ms [27-40]; p < .01 between all of them), although the QRSd for the latter two were the same (153 ms (148-158) vs. 153 ms (148-158); p = .99). RV apical capture not only had a longer LVLWd (34 ms (26-43) compared to mSp (27 ms (20-34), p < .05), but its RVLWd (17 ms (9-25) was also the longest compared to other RV pacing sites (mean values for nsHBorRBBp, mSp, anterior and lateral wall captures being below 6 ms), p < .001 compared to each of them.Conclusion RVIT pacing produces better ventricular synchrony compared to other RV pacing locations with myocardial capture. However, UHF-ECG ventricular dysynchrony seen during RVIT pacing is increased compared to concomitant capture of basal septal myocytes and His bundle or proximal right bundle branch.

Although deep brain stimulation of the subthalamic nucleus (STN-DBS) in Parkinson's disease (PD) is generally a successful therapy, adverse events and insufficient clinical effect can complicate the treatment in some patients. We studied clinical parameters and cortical oscillations related to STN-DBS to identify patients with suboptimal responses. High-density EEG was recorded during a visual oddball three-stimuli paradigm in DBS "off" and "on" conditions in 32 PD patients with STN-DBS. Pre-processed data were reconstructed into the source space and the time-frequency analysis was evaluated. We identified a subgroup of six patients with longer reaction times (RT) during the DBS "on" state than in the DBS "off" state after target stimuli. These subjects had lower motor responsiveness to DBS and decreased memory test results compared to the other subjects. Moreover, the alpha and beta power decrease (event-related desynchronizations, ERD), known as an activation correlate linked to motor and cognitive processing, was also reduced in the DBS "on" condition in these patients. A subgroup of PD patients with a suboptimal response to STN-DBS was identified. Evaluation of RT could potentially serve as a biomarker for responsiveness to STN-DBS.

Introduction The present study introduces a new ultra-high-frequency 14-lead electrocardiogram technique (UHF-ECG) for mapping ventricular depolarization patterns and calculation of novel dyssynchrony parameters that may improve the selection of patients and application of cardiac resynchronization therapy (CRT). Methods Components of the ECG in sixteen frequency bands within the 150 to 1000 Hz range were used to create ventricular depolarization maps. The maximum time difference between the UHF QRS complex centers of mass of leads V1 to V8 was defined as ventricular electrical dyssynchrony (e-DYS), and the duration at 50% of peak voltage amplitude in each lead was defined as the duration of local depolarization (Vd). Proof of principle measurements was performed in seven patients with left (left bundle branch block) and four patients with right bundle branch block (right bundle branch block) before and during CRT using biventricular and His-bundle pacing. Results The acquired activation maps reflect the activation sequence under the tested conditions. e-DYS decreased considerably more than QRS duration, during both biventricular pacing (-50% vs -8%) and His-bundle pacing (-77% vs -13%). While biventricular pacing slightly increased Vd, His-bundle pacing reduced Vd significantly (+11% vs -36%), indicating the contribution of the fast conduction system. Optimization of biventricular pacing by adjusting VV-interval showed a decrease of e-DYS from 102 to 36 ms with only a small Vd increase and QRS duration decrease. Conclusions The UHF-ECG technique provides novel information about electrical activation of the ventricles from a standard ECG electrode setup, potentially improving the selection of patients for CRT and application of CRT.

Background: We introduce a new technology that uses the ultra-high-frequency components (150-1000 Hz) of the electrocardiogram (UHF-ECG).Method: The UHF-ECG components represent weak signals generated by the depolarization of myocardial cells. The amplitude of UHF oscillations decreases with distance from the source. This property and the different timing of depolarization in the ventricles' volume enable mapping of the ventricular activation from the chest ECG leads. Because of a low signal-to-noise ratio of UHF oscillations, averaging must be performed. Single recording thus lasts 30 seconds and more.Results: UHF-ECG defines the time-spatial distribution of myocardial electrical activity. Corresponding numerical parameters are electrical dyssynchrony (e-DYS) and the duration of local depolarization (Vd). UHF ventricular depolarization maps present details of electrical activation.Conclusion: The UHF-ECG uses a new source of information originating in ventricular volumes that is different from the standard ECG. It provides information about the volumetric electrical activation associated with mechanical contraction. Its primary clinical utilization is in cardiac resynchronization, pacing optimization, and conduction system pacing.

This paper compares Ultra High Frequency ECG (UHF-ECG) with other techniques in the capacity to assess ventricular dyssynchrony. Ventricular dyssynchrony is important to identify patients that qualify for Cardiac Resynchronization Therapy (CRT) and to measure effects of CRT and other pacing therapies.Currently used tools are: duration of the QRS complex in the 12-lead ECG, vectorcardiographically determined QRSarea, ECG belt and ECG imaging. QRS duration is crude, QRSarea has been shown to predict CRT response in three large single center studies, ECG belt is a novel approach using 50-60 body surface electrodes and yields (variation in) activation times. ECG imaging requires cardiothoracic imaging and recordings using 150-250 electrodes and results in images of activation, which are converted into inter and intraventricular AT differences. UHF-ECG requires 12-14 lead ECG but provides two measures: (also) a measure of interventricular dyssynchrony (e-DYS) and a marker of width of the activation wavefront that reflects the contribution of rapid conduction. The latter is a unique feature that appears particularly useful in studies on different modes of physiological pacing.

The degree of response to subthalamic nucleus deep brain stimulation (STN‐DBS) is individual and hardly predictable. We hypothesized that DBS‐related changes in cortical network organization are related to the clinical effect. Network analysis based on graph theory was used to evaluate the high‐density electroencephalography (HDEEG) recorded during a visual three‐stimuli paradigm in 32 Parkinson's disease (PD) patients treated by STN‐DBS in stimulation “off” and “on” states. Preprocessed scalp data were reconstructed into the source space and correlated to the behavioral parameters. In the majority of patients (n = 26), STN‐DBS did not lead to changes in global network organization in large‐scale brain networks. In a subgroup of suboptimal responders (n = 6), identified according to reaction times (RT) and clinical parameters (lower Unified Parkinson's Disease Rating Scale [UPDRS] score improvement after DBS and worse performance in memory tests), decreased global connectivity in the 1–8 Hz frequency range and regional node strength in frontal areas were detected. The important role of the supplementary motor area for the optimal DBS response was demonstrated by the increased node strength and eigenvector centrality in good responders. This response was missing in the suboptimal responders. Cortical topologic architecture is modified by the response to STN‐DBS leading to a dysfunction of the large‐scale networks in suboptimal responders., Network analysis based on graph theory was used to evaluate the high‐density electroencephalography (HDEEG) recorded during a visual three‐stimuli paradigm in 32 Parkinson's disease (PD) patients treated by STN‐DBS in stimulation “off” and “on” states. Cortical topologic architecture is modified by the response to STN‐DBS leading to a dysfunction of the large‐scale networks in suboptimal responders.

The study introduces and validates a novel high-frequency (100–400 Hz bandwidth, 2 kHz sampling frequency) electrocardiographic imaging (HFECGI) technique that measures intramural ventricular electrical activation. Ex-vivo experiments and clinical measurements were employed. Ex-vivo, two pig hearts were suspended in a human-torso shaped tank using surface tank electrodes, epicardial electrode sock, and plunge electrodes. We compared conventional epicardial electrocardiographic imaging (ECGI) with intramural activation by HFECGI and verified with sock and plunge electrodes. Clinical importance of HFECGI measurements was performed on 14 patients with variable conduction abnormalities. From 3 × 4 needle and 108 sock electrodes, 256 torso or 184 body surface electrodes records, transmural activation times, sock epicardial activation times, ECGI-derived activation times, and high-frequency activation times were computed. The ex-vivo transmural measurements showed that HFECGI measures intramural electrical activation, and ECGI-HFECGI activation times differences indicate endo-to-epi or epi-to-endo conduction direction. HFECGI-derived volumetric dyssynchrony was significantly lower than epicardial ECGI dyssynchrony. HFECGI dyssynchrony was able to distinguish between intraventricular conduction disturbance and bundle branch block patients.

Prolonged QT interval is an independent risk factor for development of ventricular arrhythmias. Haloperidol is one of the drugs inducing QT prolongation. Previous studies showed that haloperidol affects not only QT duration but also heart rate (RR interval). The present work focused on relationship between QT and RR and its changes under acute and chronic haloperidol administration. The study included 14 male guinea pigs divided into control and haloperidol-treated group. After 21-days administration of haloperidol or vehiculum, electrograms in isolated hearts were recorded. QT/RR and dQT/dRR coupling were calculated. Chronic haloperidol administration significantly decreases the coupling between QT and RR. Acute haloperidol exposure significantly decreases the dQT/dRR coupling in both treated and untreated guinea pig hearts. Flatter QT/RR relationship reveals a lack of QT adaptation to increased heart rate. It should be emphasized that in such situation ECG recording will not show significant QT prolongation evaluated according to clinical rules. However, if QT interval does not adapt to increased heart rate sufficiently, the risk of ventricular arrhythmias may be increased despite practically normal QT interval length. The results are supported by findings in biochemical analyses, which proved eligibility of the used model. Keywords: Drug-induced QT prolongation, Guinea pig, Haloperidol, Isolated heart, QT/RR coupling

Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): This paper was supported by the Charles University Research Centre program No. UNCE/MED/002 and 260530/SVV/2020 Background Direct and indirect pacing of the left bundle branch are novel pacing techniques preserving LV synchrony. Aim of the study was to compare differences in ventricular activation between them using an UHF-ECG. Methods The left septal lead placement was done in 68 patients with bradycardia. Four distinct ventricular captures were described; nonselective LBBp (nsLBBp), selective LBBp (sLBBp), paraLBBp and left bundle branch area capture (LBBap). The timings of local ventricular activations and local depolarization durations were displayed by the UHF-ECG. e-DYS was calculated as a difference between the first and last activation. Results There were 35 nsLBBp, 21 paraLBBp, 12 sLBBp and 96 LBBap obtained in 68 patients. The nsLBBp compared to LBBap caused worse interventricular synchrony (e-DYS -23 ms (-28;-18) vs -12 ms (-17;-8), p < 0.001), but improved LV lateral wall depolarization duration. The sLBBp, nsLBBp and paraLBBp differed in e-DYS; -31 ms (-38;-24) vs -23 ms (-28;-17) vs -13 ms (-20;-7), p < 0.01 between each of them. Their left ventricular depolarization durations were the same, but they were longer when pacing resulted in the left axis deviation. If the direct capture of the LBB was not confirmed (LBBap), LV depolarization duration was deteriorated irrespective of the QSR morphology in the V1 or RWPT in the V5. Examples of UHF-ECG maps during LBBap, paraLBBp and nsLBBp are shown in Figure 1. Conclusions The direct capture of the left bundle branch deteriorates interventriclar synchrony but improves the depolarization duration of the left ventricular lateral wall compared to left ventricular myocardial septal pacing. Abstract Figure 1

We hypothesized that local/regional properties of stimulated structure/circuitry contribute to the effect of deep brain stimulation (DBS). We analyzed intracerebral electroencephalographic (EEG) recordings from externalized DBS electrodes targeted bilaterally in the anterior nuclei of the thalamus (ANT) in 12 patients (six responders, six nonresponders) with more than 1 year of follow-up care. In the bipolar local field potentials of the EEG, spectral power (PW) and power spectral entropy (PSE) were calculated in the passbands 1-4, 4-8, 8-12, 12-20, 20-45, 65-80, 80-200 and 200-500 Hz. The most significant differences between responders and nonresponders were observed in the BRIDGE area (bipolar recordings with one contact within the ANT and the second contact in adjacent tissue). In responders, PW was significantly decreased in the frequency bands of 65-80, 80-200, and 200-500 Hz (p

Nonselective His-bundle pacing (nsHBp), nonselective left bundle branch pacing (nsLBBp), and left ventricular septal myocardial pacing (LVSP) are recognized as physiological pacing techniques.The purpose of this study was to compare differences in ventricular depolarization between these techniques using ultra-high-frequency electrocardiography (UHF-ECG).In patients with bradycardia, nsHBp, nsLBBp (confirmed concomitant left bundle branch [LBB] and myocardial capture), and LVSP (pacing in left ventricular [LV] septal position without proven LBB capture) were performed. Timings of ventricular activations in precordial leads were displayed using UHF-ECG, and electrical dyssynchrony (e-DYS) was calculated as the difference between the first and last activation. Duration of local depolarization (Vd) was determined as width of the UHF-QRS complex at 50% of its amplitude.In 68 patients, data were collected during nsLBBp (35), LVSP (96), and nsHBp (55). nsLBBp resulted in larger e-DYS than did LVSP and nsHBp [- 24 ms (-28;-19) vs -12 ms (-16;-9) vs 10 ms (7;14), respectively; P.001]. nsLBBp produced similar values of Vd in leads Vnslbbp preserves physiological LV depolarization but increases interventricular electrical dyssynchrony. LV lateral wall depolarization during LVSP is prolonged, but interventricular synchrony is preserved.

Background: Permanent cardiac pacing can cause heart failure, with the ventricular dyssynchrony being identified as the main cause for its development.Method: His bundle pacing (HBp), left bundle branch pacing (LBBp), and left ventricular myocardial septal pacing (LVSP) were introduced recently. Their impact on ventricular dyssynchrony was not known. We used ultra-high-frequency ECG (UHF-ECG) to compare ventricular depolarization in these pacing techniques.Results: We showed the nonselective HB pacing produces the same pattern of UHF-ECG ventricular depolarization as selective HB pacing. Next, we showed the nonselective His bundle pacing in the area below the tricuspid valve has the best interventricular synchrony from all other RV pacing locations with myocardial capture. We also compared UHF-ECG-derived parameters of ventricular depolarization during HBp, LBBp, and LVSP and we showed that both pacing types from the left septal area are less physiological than nsHBp.Conclusion: UHF-ECG is an effective tool that can be used in clinical practice to assess the electrical dyssynchrony caused by cardiac pacing. Furthermore, its real-time implementation allows recognizing between physiological vs. non-physiological pacing during an implant procedure.

Background: Identification of paced beats is a necessity for Holter ECG monitoring reports. However, lower sampling frequencies make the pacing stimuli hard to identify. In this study, we present a method to distinguish between paced and non-paced beats. Method: One-hour ECG recordings (158 patients, single lead, 250 Hz) were recorded during usual daily activities. A total of 44,918 QRS complexes were detected and marked as paced (19,004) or non-paced (25,914). This dataset was split (60%, out-of-patient) to training and testing datasets. Three features based on amplitude envelopes in two frequency bands were used to build a logistic regression model. An additional external dataset (2,193 recordings with 16,941 QRS) was assessed at a different facility and was used for the cross-database test. Results: The model showed the test Fl-score of 0.93, cross-database test shown Fl-score of 0.924. Conclusion: The presented method recognizes paced and non-paced heartbeats in lower sampling frequency, even if it can hardly be visually observed in the raw signal.

Cardiac diseases are the most common cause of death. The fully automated classification of the electrocardiogram (ECG) supports early capturing of heart disorders, and, consequently, may help to get treatment early. Here in this paper, we introduce a deep neural network for human ECG classification into 24 independent groups, for example, atrial fibrillation, 1st degree AV block, Bundle branch blocks, premature contractions, changes in the ST segment, normal sinus rhythm, and others. The network architecture utilizes a convolutional neural network with residual blocks, bidirectional Gated Recurrent Units, and an attention mechanism. The algorithm was trained and validated on the public dataset proposed by the PhysioNet Challenge 2020. The trained algorithm was tested using a hidden test set during the official phase of the challenge and obtained the challenge validation score of 0.659 as entries by the ISIBrno team. The final testing scores were 0.847, 0.195, −0.006, and 0.122, for testing sets I, II, III, and full test set, respectively. We have obtained 30th place out of 41 teams in the official ranking.

Background: Right ventricular (RV) pacing causes delayed activation of remote ventricular segments. We used the UHF-ECG to describe ventricular depolarization when pacing different RV locations. Methods: In 51 consecutive patients, temporary pacing was performed at the RV apex, anterior and lateral wall, and at the RV septum with (cSp) and without direct conductive tissue engagement (mSp) (further subclassified as RVIT and RVOT for septal inflow and outflow positions). The timing of UHF-ECG electrical activations were quantified as: left ventricular lateral wall delay (LVLWd; V8 activation delay), RV lateral wall delay (RVLWd; V1 activation delay), and LV lateral wall depolarization duration (V5-8d). Results: The LVLWd was shortest for cSp (11 ms (95% CI; 5;17), followed by the RVIT (19 ms (11;26) and the RVOT (33 ms (27;40), (p

Background Nonselective pacing of the distal His bundle is practically just another way of right ventricular septal pacing. It leads to the concomitant activation of the His bundle and septal myocytes with unknown impact on ventricular synchrony. Ultra-high frequency ECG (UHF-ECG) is a novel tool for ventricular depolarization imaging. Purpose To describe ventricular depolarization patterns during nonselective pacing of a ventricular aspect of His bundle and myocardial captures from different locations in the right ventricle by using the UHF-ECG. Methods Consecutive patients with an indication for permanent pacing due to bradycardia were included. During pacemaker implantation, the pacing lead was temporarily placed in prespecified locations of the right ventricle (mid-septum, anterior, lateral wall, and the para-hisian area of the RV). When pacing from mentioned locations, myocardial activation time under each specific lead (Vd), and ventricular dyssynchrony (e-DYS) indexes were calculated from UHF-ECG maps, for each particular type of pacing. The demonstration of UHF-ECG maps during pacing from different locations of the right ventricle is shown in the figure. Results Two hundred and fifty UHF ECG recordings were performed in forty-six patients. The calculated mean e-DYS parameter was significantly shorter during non-selective capture of the distal His bundle (14±8 ms) compared to each of myocardial captures of the right ventricle (pure myocardial para-hisian; 35±12 ms, mid-septal; 28±11 ms, anterior wall; 51±16 ms and lateral wall; 62±19 ms (p Conclusion Pacing of the basal interventricular septum with the engagement of the His bundle produced a superior depolarization pattern in both heart ventricles compared to other types of right ventricular myocardial capture, as assessed using UHF-ECG. Figure 1. Examples of UHF-ECG depolarization maps of different types of ventricular activation in the same patient. Funding Acknowledgement Type of funding source: Public Institution(s). Main funding source(s): Charles University in Prague

Vagal Nerve Stimulation (VNS) is an option in the treatment of drug-resistant epilepsy. However, approximately a quarter of VNS subjects does not respond to the therapy. In this retrospective study, we introduce heart-rate features to distinguish VNS responders and non-responders. Standard pre-implantation measurements of 66 patients were segmented in relation to specific stimuli (open/close eyes, photic stimulation, hyperventilation, and rests between). Median interbeat intervals were found for each segment and normalized (NMRR). Five NMRRs were significant; the strongest feature achieved significance with p=0.013 and AUC=0.66. Low mutual correlation and independence on EEG signals mean that presented features could be considered as an addition for models predicting VNS response using EEG.

EEG signal processing is a fundamental method for neurophysiology research and clinical neurology practice. Historically the classification of EEG into physiological, pathological, or artifacts has been performed by expert visual review of the recordings. However, the size of EEG data recordings is rapidly increasing with a trend for higher channel counts, greater sampling frequency, and longer recording duration and complete reliance on visual data review is not sustainable. In this study, we publicly share annotated intracranial EEG data clips from two institutions: Mayo Clinic, MN, USA and St. Anne’s University Hospital Brno, Czech Republic. The dataset contains intracranial EEG that are labeled into three groups: physiological activity, pathological/epileptic activity, and artifactual signals. The dataset published here should support and facilitate training of generalized machine learning and digital signal processing methods for intracranial EEG and promote research reproducibility. Along with the data, we also propose a statistical method that is recommended for comparison of candidate classifier performance utilizing out-of-institution/out-of-patient testing., Measurement(s)brain measurement • physiological activity • epileptic seizure AE • Artifact • AnnotationTechnology Type(s)electroencephalography (EEG) • intracranial electroencephalography • data transformationFactor Type(s)institutionSample Characteristic - OrganismHomo sapiens Machine-accessible metadata file describing the reported data: 10.6084/m9.figshare.12326471

BACKGROUND: Cardiac resynchronization therapy (CRT) is an established treatment in patients with heart failure and conduction abnormalities. However, a significant number of patients do not respond to CRT. Currently employed criteria for selection of patients for this therapy (QRS duration and morphology) have several shortcomings. QRS area was recently shown to provide superior association with CRT response. However, its assessment was not fully automated and required the presence of an expert.OBJECTIVE: Our objective was to develop a fully automated method for the assessment of vector-cardiographic (VCG) QRS area from electrocardiographic (ECG) signals.METHODS: Pre-implantation ECG recordings (N = 864, 695 left-bundle-branch block, 589 men) in PDF files were converted to allow signal processing. QRS complexes were found and clustered into morphological groups. Signals were converted from 12‑lead ECG to 3‑lead VCG and an average QRS complex was built. QRS area was computed from individual areas in the X, Y and Z leads. Practical usability was evaluated using Kaplan-Meier plots and 5-year follow-up data.RESULTS: The automatically calculated QRS area values were 123 ± 48 μV.s (mean values and SD), while the manually determined QRS area values were 116 ± 51 ms; the correlation coefficient between the two was r = 0.97. The automated and manual methods showed the same ability to stratify the population (hazard ratios 2.09 vs 2.03, respectively).CONCLUSION: The presented approach allows the fully automatic and objective assessment of QRS area values.SIGNIFICANCE: Until this study, assessing QRS area values required an expert, which means both additional costs and a risk of subjectivity. The presented approach eliminates these disadvantages and is publicly available as part of free signal-processing software.

Right ventricular myocardial pacing leads to nonphysiological activation of heart ventricles. Contrary to this, His bundle pacing preserves their fast activation. Ultra-high-frequency electrocardiography (UHF-ECG) is a novel tool for ventricular depolarization assessment.The purpose of this study was to describe UHF-ECG depolarization patterns during myocardial and His bundle pacing.Forty-six patients undergoing His bundle pacing to treat bradycardia and spontaneous QRS complexes without bundle branch block were included. UHF-ECG recordings were performed during spontaneous rhythm, pure myocardial para-Hisian capture, and His bundle capture. QRS duration, QRS area, depolarization time in specific leads, and the UHF-ECG-derived ventricular dyssynchrony index were calculated.One hundred thirty-three UHF-ECG recordings were performed in 46 patients (44 spontaneous rhythm, 28 selective His bundle, 43 nonselective His bundle, and 18 myocardial capture). The mean QRS duration was 117 ms for spontaneous rhythm, 118 ms for selective, 135 ms for nonselective, and 166 ms for myocardial capture (P.001 for nonselective and myocardial capture compared to each of the other types of ventricular activation). The calculated dyssynchrony index was shortest during spontaneous rhythm (12 ms; P = .02 compared to selective and P = .09 compared to nonselective), and it did not differ between selective and nonselective His bundle capture (16 vs 15 ms; P.99) and was longest during myocardial capture of the para-Hisian area (37 ms; P.001 compared to each of the other types of ventricular activation).In patients without bundle branch block, both types of His bundle, but not myocardial, capture preserve ventricular electrical synchrony as measured using UHF-ECG.

Introduction: The aim was to compare event-related potentials and event-related de/synchronisations between the P300 and mismatch negativity paradigms, both recorded in the subcortical structures and thus illustrate conscious cognition process in these structures. The second aim was to uncover if the mismatch negativity can be found in subcortical structures. Methods: We included patients with Parkinson's disease, generalised dystonia, essential tremor and epilepsy in the deep brain stimulation program. The electrodes were implanted into the subthalamic nucleus, internal globus pallidus, then in the anterior and ventral intermediate nucleus of the thalamus bilaterally. We were interested in local oscillations. Results: We found a significant P300 - mismatch negativity difference at 250-400 ms latency in the basal ganglia and thalamus in event-related potentials in 7 out of 8 patients. There was also a significant difference in eventrelated de/synchronisations at 500-1500 ms latency in 7 out of 8 patients in the beta band and desynchronisation in the subthalamic nucleus plus the internal globus pallidus and synchronisation in the anterior thalamic nucleus. When the mismatch negativity protocol was processed we found a significant outcome in event-related potentials (100-250 ms latency) in the internal globus pallidus and the ventral intermediate nucleus of the thalamus in 4 out of 6 patients. Conclusion: The results suggest that the subthalamic nucleus, internal globus pallidus and maybe also the thalamus are involved firstly in the subconscious cognitive process 100-250 ms after the stimuli, then in the conscious cognitive processes at the level of the afferent information processing network at 250-400 ms and finally they affect conscious cognitive activity at a time of large brain neuronal network 500-1500 ms after stimuli.