On the Einthoven Triangle: A Critical Analysis of the Single Rotating Dipole Hypothesis

Gaetano Gargiulo; Paolo Bifulco; Mario Cesarelli; Alistair McEwan; Hossein Moeinzadeh; Aiden O’Loughlin; Ibrahim Shugman; Jonathan Tapson; Aravinda Thiagalingam

doi:10.3390/s18072353

On the Einthoven Triangle: A Critical Analysis of the Single Rotating Dipole Hypothesis

Sensors ◽

10.3390/s18072353 ◽

2018 ◽

Vol 18 (7) ◽

pp. 2353 ◽

Cited By ~ 6

Author(s):

Gaetano Gargiulo ◽

Paolo Bifulco ◽

Mario Cesarelli ◽

Alistair McEwan ◽

Hossein Moeinzadeh ◽

...

Keyword(s):

Efficient Algorithm ◽

Equilateral Triangle ◽

Critical Analysis ◽

Cardiac Cycle ◽

Cardiac Activity ◽

Central Point ◽

Current Circulation ◽

Central Terminal

Since its inception, electrocardiography has been based on the simplifying hypothesis that cardinal limb leads form an equilateral triangle of which, at the center/centroid, the electrical equivalent of the cardiac activity rotates during the cardiac cycle. Therefore, it is thought that the three limbs (right arm, left arm, and left leg) which enclose the heart into a circuit, where each branch directly implies current circulation through the heart, can be averaged together to form a stationary reference (central terminal) for precordials/chest-leads. Our hypothesis is that cardinal limbs do not form a triangle for the majority of the duration of the cardiac cycle. As a corollary, the central point may not lie in the plane identified by the limb leads. Using a simple and efficient algorithm, we demonstrate that the portion of the cardiac cycle where the three limb leads form a triangle is, on average less, than 50%.

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Respiration, heartbeat, and conscious tactile perception

10.1101/2021.03.22.436396 ◽

2021 ◽

Author(s):

Martin Grund ◽

Esra Al ◽

Marc Pabst ◽

Alice Dabbagh ◽

Tilman Stephani ◽

...

Keyword(s):

Cognitive Processing ◽

Detection Rate ◽

Cardiac Cycle ◽

Pulse Wave ◽

Cognitive Task ◽

Cardiac Activity ◽

Tactile Perception ◽

Left Index Finger ◽

Tactile Stimuli ◽

Tactile Detection

Cardiac activity has been shown to interact with conscious tactile perception: Detecting near-threshold tactile stimuli is more likely during diastole than systole and heart slowing is more pronounced for detected compared to undetected stimuli. Here, we investigated how cardiac cycle effects on conscious tactile perception relate to respiration given the natural coupling of these two dominant body rhythms. Forty-one healthy participants had to report conscious perception of weak electrical pulses applied to the left index finger (yes/no) and confidence about their yes/no-decision (unconfident/confident) while electrocardiography (ECG), respiratory activity (chest circumference), and finger pulse oximetry were recorded. We confirmed the previous findings of higher tactile detection rate during diastole and unimodal distribution of hits in diastole, more specifically, we found this only when participants were confident about their detection decision. Lowest tactile detection rate occurred 250-300 ms after the R-peak corresponding to pulse-wave onsets in the finger. Inspiration was locked to tactile stimulation, and this was more consistent in hits than misses. Respiratory cycles accompanying misses were longer as compared to hits and correct rejections. Cardiac cycle effects on conscious tactile perception interact with decision confidence and coincide with pulse-wave arrival, which suggests the involvement of higher cognitive processing in this phenomenon possibly related to predictive coding. The more consistent phase-locking of inspiration with stimulus onsets for hits than misses is in line with previous reports of phase-locked inspiration to cognitive task onsets which were interpreted as tuning the sensory system for incoming information.

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WCTECGdb: A 12-Lead Electrocardiography Dataset Recorded Simultaneously with Raw Exploring Electrodes’ Potential Directly Referred to the Right Leg

Sensors ◽

10.3390/s20113275 ◽

2020 ◽

Vol 20 (11) ◽

pp. 3275

Author(s):

Hossein Moeinzadeh ◽

Joseph Assad ◽

Paolo Bifulco ◽

Mario Cesarelli ◽

Aiden O’Loughlin ◽

...

Keyword(s):

Large Amplitude ◽

Cardiac Cycle ◽

P Wave ◽

T Wave ◽

Conductive Pathway ◽

Initial Assumption ◽

Case Assessment ◽

The Right ◽

Central Terminal

With this paper we communicated the existence of a surface electrocardiography (ECG) recordings dataset, named WCTECGdb, that aside from the standard 12-lead signals includes the raw electrode biopotential for each of the nine exploring electrodes refereed directly to the right leg. This dataset, comprises of 540 ten second segments recorded from 92 patients at Campbelltown Hospital, NSW Australia, and is now available for download from the Physionet platform. The data included in the dataset confirm that the Wilson’s Central Terminal (WCT) has a relatively large amplitude (up to 247% of lead II) with standard ECG characteristics such as a p-wave and a t-wave, and is highly variable during the cardiac cycle. As further examples of application for our data, we assess: (1) the presence of a conductive pathway between the legs and the heart concluding that in some cases is electrically significant and (2) the initial assumption about the limbs potential stating the dominance of the left arm concluding that this is not always the case and that might requires case to case assessment.

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Reactive hyperemia following one-beat coronary occlusions in the awake dog

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1986.250.3.h474 ◽

1986 ◽

Vol 250 (3) ◽

pp. H474-H481

Author(s):

R. J. Bache ◽

D. S. Hess

Keyword(s):

Heart Rate ◽

Coronary Flow ◽

Coronary Occlusion ◽

Cardiac Cycle ◽

Reactive Hyperemia ◽

Cardiac Activity ◽

Cardiac Pacing ◽

Single Cycle ◽

Ventricular Stimulation ◽

Hyperemic Response

This study was performed to examine the effect of alterations of cardiac activity during brief coronary artery occlusions on the subsequent reactive hyperemic response. Reactive hyperemia following coronary occlusions equal in duration to one cardiac cycle were examined in 12 chronically instrumented awake dogs while heart rate was maintained constant by cardiac pacing. During continuous pacing, one-beat coronary occlusions resulted in reactive hyperemia with excess flow equal to 220 +/- 23% blood flow debt repayment. When coronary occlusions of identical duration were performed while a single cycle of pacing was omitted during the interval of occlusion, the subsequent reactive hyperemia was decreased. Conversely, when coronary occlusion was produced during the first potentiated beat following a single cycle of paired ventricular stimulation, the reactive hyperemia was increased. Since, in the absence of coronary occlusion, omitting a single paced beat caused a transient decrease in coronary flow, while a single cycle of paired ventricular stimulation caused a brief increase in coronary flow, the reactive hyperemic responses were corrected for these perturbations in flow. Despite these corrections, the influence of alterations of myocardial activity during the interval of occlusion persisted, with the decreased reactive hyperemia when occlusion occurred during an omitted beat and increased hyperemia when occlusion was performed during a potentiated beat. These data indicate substantial coupling between myocardial activity during coronary occlusions as brief as one cardiac cycle in duration and the subsequent reactive hyperemic response.

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Cardiac Activity Impacts Cortical Motor Excitability

10.21203/rs.3.rs-1023617/v1 ◽

2021 ◽

Author(s):

Esra Al ◽

Tilman Stephani ◽

Melina Engelhardt ◽

Arno Villringer ◽

Vadim Nikulin

Keyword(s):

Cardiac Cycle ◽

Cortical Excitability ◽

Time Windows ◽

Motor Task ◽

Cardiac Activity ◽

Corticospinal Excitability ◽

Human Cognition ◽

Facilitatory Effect ◽

Cortical Responses ◽

Motor Excitability

Abstract Human cognition and action can be influenced by internal bodily processes such as heartbeats. For instance, somatosensory perception is impaired both during the systolic phase of the cardiac cycle and when heartbeats evoke stronger cortical responses. Here, we test whether these cardiac effects originate from overall changes in cortical excitability. Cortical and corticospinal excitability were assessed using electroencephalographic and electromyographic responses to transcranial magnetic stimulation while concurrently monitoring cardiac activity with electrocardiography. Cortical and corticospinal excitability were found to be highest during systole and following stronger cortical responses to heartbeats. Furthermore, in a motor task, hand-muscle activity and the associated desynchronization of sensorimotor oscillations were stronger during systole. These results suggest that systolic cardiac signals have a facilitatory effect on motor excitability – in contrast to sensory attenuation that was previously reported for somatosensory perception. Thus, distinct time windows may exist across the cardiac cycle that either optimize perception or action.

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Bell’s “Theorem”: loopholes vs. conceptual flaws

Open Physics ◽

10.1515/phys-2017-0088 ◽

2017 ◽

Vol 15 (1) ◽

pp. 754-761

Author(s):

A. F. Kracklauer

Keyword(s):

Quantum Theory ◽

Critical Analysis ◽

Current Theory ◽

Central Point ◽

Bell’S Theorem ◽

Historical Overview ◽

Bell's Theorem ◽

Conditional Probabilities

AbstractAn historical overview and detailed explication of a critical analysis of what has become known as Bell’s Theorem to the effect that, it should be impossible to extend Quantum Theory with the addition of local, real variables so as to obtain a version free of the ambiguous and preternatural features of the currently accepted interpretations is presented. The central point on which this critical analysis, due originally to Edwin Jaynes, is that Bell incorrectly applied probabilistic formulas involving conditional probabilities. In addition, mathematical technicalities that have complicated the understanding of the logical or mathematical setting in which current theory and experimentation are embedded, are discussed. Finally, some historical speculations on the sociological environment, in particular misleading aspects, in which recent generations of physicists lived and worked are mentioned.

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Interactions between cardiac activity and conscious somatosensory perception

10.1101/529636 ◽

2019 ◽

Author(s):

Paweł Motyka ◽

Martin Grund ◽

Norman Forschack ◽

Esra Al ◽

Arno Villringer ◽

...

Keyword(s):

Heart Rate ◽

Cardiac Cycle ◽

Physiological State ◽

Cardiac Activity ◽

The Body ◽

Cardiac Deceleration ◽

Electrical Pulses ◽

Somatosensory Stimuli ◽

External Stimuli ◽

Near Threshold

AbstractFluctuations in the heart’s activity can modulate the access of external stimuli to consciousness. The link between perceptual awareness and cardiac signals has been investigated mainly in the visual and auditory domain. We here investigated whether the phase of the cardiac cycle and the pre-stimulus heart rate influence conscious somatosensory perception. We also tested how conscious detection of somatosensory stimuli affects the heart rate. Electrocardiograms (ECG) of 33 healthy volunteers were recorded while applying near-threshold electrical pulses at a fixed intensity to the left index finger. Conscious detection was not uniformly distributed across the cardiac cycle but significantly higher in diastole than in systole. We found no evidence that the heart rate before a stimulus influenced its detection but hits (correctly detected somatosensory stimuli) led to a more pronounced cardiac deceleration than misses. Our findings demonstrate interactions between cardiac activity and conscious somatosensory perception, which highlights the importance of internal bodily states for sensory processing beyond the auditory and visual domain.Impact StatementIt is highly debated to what extent cardiac activity modulates the access of external stimuli to consciousness. The evidence is inconsistent across sensory modalities and previous research focused at specific intervals within the cardiac cycle. Here, we examined the perception of near-threshold electrical pulses across the entire cardiac cycle. Our results show that conscious somatosensory perception is enhanced during the late phase of the cardiac cycle (at diastole) and associated with a more pronounced cardiac deceleration (as compared to non-detected stimuli). This strengthens the evidence that the physiological state of the body influences how we perceive the world.

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True Unipolar ECG Machine for Wilson Central Terminal Measurements

BioMed Research International ◽

10.1155/2015/586397 ◽

2015 ◽

Vol 2015 ◽

pp. 1-7 ◽

Cited By ~ 13

Author(s):

Gaetano D. Gargiulo

Keyword(s):

Medical Practice ◽

Cardiac Cycle ◽

Reference Voltage ◽

Voltage Reference ◽

Research Attention ◽

And Behavior ◽

Central Terminal ◽

Stable Voltage ◽

Four Electrodes

Since its invention (more than 80 years ago), modern electrocardiography has employed a supposedly stable voltage reference (with little variation during the cardiac cycle) for half of the signals. This reference, known by the name of “Wilson Central Terminal” in honor of its inventor, is obtained by averaging the three active limb electrode voltages measured with respect to the return ground electrode. However, concerns have been raised by researchers about problems (biasing and misdiagnosis) associated with the ambiguous value and behavior of this reference voltage, which requires perfect and balanced contact of at least four electrodes to work properly. The Wilson Central Terminal has received scant research attention in the last few decades even though consideration of recent widespread medical practice (limb electrodes are repositioned closer to the torso for resting electrocardiography) has also sparkled concerns about the validity and diagnostic fitness of leads not referred to the Wilson Central Terminal. Using a true unipolar electrocardiography device capable of precisely measuring the Wilson Central Terminal, we show its unpredictable variability during the cardiac cycle and confirm that the integrity of cardinal leads is compromised as well as the Wilson Central Terminal when limb electrodes are placed close to the torso.

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Computational Micrograph Registration with Sieve Processes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100164660 ◽

1996 ◽

Vol 54 ◽

pp. 440-441

Author(s):

P.J. Phillips ◽

J. Huang ◽

S. M. Dunn

Keyword(s):

Planar Graph ◽

Efficient Algorithm ◽

Spatial Organization ◽

Spatial Arrangement ◽

Stereo Image ◽

Image Model ◽

Geometric Invariants ◽

Point Set

In this paper we present an efficient algorithm for automatically finding the correspondence between pairs of stereo micrographs, the key step in forming a stereo image. The computation burden in this problem is solving for the optimal mapping and transformation between the two micrographs. In this paper, we present a sieve algorithm for efficiently estimating the transformation and correspondence.In a sieve algorithm, a sequence of stages gradually reduce the number of transformations and correspondences that need to be examined, i.e., the analogy of sieving through the set of mappings with gradually finer meshes until the answer is found. The set of sieves is derived from an image model, here a planar graph that encodes the spatial organization of the features. In the sieve algorithm, the graph represents the spatial arrangement of objects in the image. The algorithm for finding the correspondence restricts its attention to the graph, with the correspondence being found by a combination of graph matchings, point set matching and geometric invariants.

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