RELATIONSHIP AMONG QRS COMPLEX CHARACTERS IN ELECTROCARDIOGRAM AND ITS APPLICATION TO MYOCARDIAL ISCHEMIA

Electrocardiogram (ECG) is a noninvasive, economic, and convenient detecting tool in myocardial ischemia (MI), and its clinical appearance is mainly exhibited by ST-T complex changes. Recently, QRS complex characters in detecting MI were proposed by an increasing number of researchers. In this paper, various QRS complex characters were extracted in ECG, and their relationship was analyzed systematically. As a result, these characters were divided into two groups, and there was good correlation among them in each group, while the correlation between the groups was poor. Finally, these QRS complex characters were applied to myocardial ischemia, and five characters had significant differences after 59 normal ECG recordings verification, which were: QRS upward and downward slopes, transient heart rate, angle R and angle Q in a triangle QRS. Experimental results showed it was apparent that the trend changes of these five characters when MI events occurred were consistent with their relationship. The conduction velocity of action potentials in ventricular depolarization is slower in MI states than in normal states.

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Design of a Programmable ECG Generator Using a Dynamical Model

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.311.485 ◽

2013 ◽

Vol 311 ◽

pp. 485-490 ◽

Cited By ~ 2

Author(s):

Ying Chieh Wei ◽

Ying Yu Wei ◽

Shaang Tzuu Wey ◽

Ling Sheng Jang

Keyword(s):

Differential Equation ◽

Heart Rate ◽

Flash Memory ◽

Qrs Complex ◽

Universal Serial Bus ◽

Bundle Branch Block ◽

T Wave ◽

Efficiency Of Algorithms ◽

Different Types ◽

Electrocardiogram Ecg

This article is to design and develop a programming electrocardiogram (ECG) generator. It can be used to test the efficiency of algorithms and to calibration and maintenance of electrocardiograph equipment. We simplified and modified the three coupled ordinary differential equations of McSharry’s model to single differential equation to generate the synthetic ECG waveforms. This generator can provide the adjusted amplitude, heart rate, QRS-complex slopes, and P- and T-wave position parameters. The system can set the rage of the average gear rate from 20 to 120 beat per minute (BPM) with an adjustable variation of 1 BPM. The parameters of the adjusted synthetic ECG model can be stored in Flash memory of the system through Universal Serial Bus (USB) 2.0 interface. The results were generated four different ECG waveforms for test which are Lead I, Lead II, hyperkalaemia and left bundle branch block. According to the experimental results, the system can not only generate the ECG waveforms of the setting heart rate but also can adjust the different types of ECG waveforms. ECG generator will generate the synthetic electrocardiograms for testing the electrocardiogram analytic algorithms. ECG generator will generate the synthetic electrocardiograms for testing the electrocardiogram analytic algorithms.

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Electrocardiogram of the reindeer, Rangifer tarandus tarandus

Laboratory Animals ◽

10.1258/002367779780937924 ◽

1979 ◽

Vol 13 (3) ◽

pp. 183-186 ◽

Cited By ~ 2

Author(s):

J. TimisjÄrvi ◽

L. Hirvonen ◽

P. JÄrvensivu ◽

M. Nieminen

Keyword(s):

Heart Rate ◽

Rangifer Tarandus ◽

Frontal Plane ◽

Conduction Time ◽

Qrs Complex ◽

Rangifer Tarandus Tarandus ◽

Newborn Calves ◽

Ventricular Depolarization

Summary Electrocardiograms were recorded for 50 Finnish reindeer of age 1 day to 9 years, using standard and unipolar extremity leads in the frontal plane. The range of heart rate was 40–250 beats per minute. Atrial and ventricular depolarization times were 5–10 ms shorter in newborn calves than in older reindeer, and showed only minor variance with respect to heart rate. The duration of depolarization was dependant on heart rate, and was more rapid in young calves. A-V conduction time decreased with increasing heart rate. The mode of the QRS vector was 280–290°, and the mode of the T vector 200–230° in the older animals, but 100–120° in young calves. The main deflection in the QRS complex was S in the leads II, III and aVF. R was dominant in aVL and I.

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Characteristics of the reindeer electrocardiogram

Rangifer ◽

10.7557/2.2.2.412 ◽

1982 ◽

Vol 2 (2) ◽

pp. 36

Author(s):

Jouni Timisjärvi ◽

Mauri Nieminen ◽

Sven Nikander

Keyword(s):

Heart Rate ◽

Indirect Evidence ◽

Frontal Plane ◽

Heart Beat ◽

P Wave ◽

Qrs Complex ◽

Single Plane ◽

T Wave ◽

Wide Range ◽

Electrocardiogram Ecg

The electrocardiogram (ECG) provides reliable information about heart rate, initiation of heart beat and also, to some degree, indirect evidence on the functional state of the heart muscle. A wide range of such information is readily obtainable from conventional scalar leads, even if the records are limited to a single plane. The present investigation deals with the normal reindeer ECG in the frontal plane. The technique used is the scalar recording technique based on the Einthovenian postulates. The P wave was positive in leads II, III and aVF, negative in lead aVL and variable in leads I and aVR. The direction of the P vector was 60 to 120°. The QRS complex was variable. The most common forms of QRS complex were R and rS in leads I and aVR; R, Rs and rS in lead aVL and Qr or qR in other leads. The most common direction of the QRS vector was 240 to 300°. The T wave was variable. The duration of various intervals and deflection depended on heart rate.Elektrokardiogram på ren.Abstract in Swedish / Sammandrag: Elektrokardiogramet (EKG) ger tillförlitliga uppgifter om hjärtfrekvens, retledning och, indirekt, delvis även om hjärtmuskelns funktionell tillstånd. Största delen av denna information fås med normal skalar koppling även om registrering sker i ett plan. I detta arbete har renens normala EKG i frontalplanet undersökts. Kopplingarna har baserats på Einthovs postulat. P-vågen var riktad uppåt i koppling II, III och aVF, nedåt i koppling aVL och den varierade i koppling I och aVR. P-vektorns riktning var 60 - 120°. QRS-komplexet varierade. De vanligaste formerna var R och rS i koppling I och aVR; R, Rs och rS i koppling aVL och Qr eller qR i andra kopplingar. Vanligen var QRS-vektorns riktning 240 - 300°. T-vågen varierade. Awikelserna och intervallernas längd var beroende av hiärtfrekvenssen.Poron sydänsähkökäyrän ominaisuuksia.Abstract in Finnish / Yhteenveto: Sydänsähkökäyrästä saadaan luotettavaa tietoa sydämen syketiheydestä, sähköisestä johtumisesta ja välillisesti jossain määrin myös sydänlihaksen toiminnallisesta tilasta. Suurin osa tämänkaltaista tietoa voidaan saada tavanomaisia skalaarisia kytkentöjäkäyttäen, ja usein yhdessä tasossa tapahtuva rekisteröinti on riittävä. Tässä työssä on tutkittu porojen normaalia sydänsähkökäyrää ja sen eri poikkeamien suuntautumista frontaalitasossa, kun rekisteröinnissä on käytetty Einthovenin postulaattien mukaisia raajakytkentöjä. P aalto suuntautui ylöspäin kythkennöissä II, III ja aVF, alaspäin kytkennässä aVL ja vaihteli kytkennöissä I ja aVR. P vektorin suunta oli 60 - 120°. QRS kompleksi vaihteli. Tavallisimmat muodot olivat R ja rS kytkennöissä I ja aVR; R, Rs ja rS kytkennässä aVL ja Qr tai qR muissa kytkennöissä. Tavallisin QRS vektorin suunta oli 240 - 300°. T aalto vaihteli. Poikkeaminen ja intervallien kesto riippui sydämen syketiheydestä.

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Reversibility of a High-Grade Atrioventricular Block Treated Homeopathically

Homœopathic Links ◽

10.1055/s-0041-1725087 ◽

2021 ◽

Vol 34 (01) ◽

pp. 052-061

Author(s):

Herman John Daniel Jeggels

Keyword(s):

Myocardial Infarction ◽

Acute Myocardial Infarction ◽

Heart Rate ◽

Atrioventricular Node ◽

High Grade ◽

Qrs Complex ◽

Junctional Rhythm ◽

Narrow Qrs ◽

Narrow Qrs Complex ◽

Electrocardiogram Ecg

Abstract: Background A 61-year-old female patient requested a homeopathic therapy as an alternative to a pacemaker for a non-acute myocardial infarction, high-grade atrioventricular node block (HG-AVNB) with a narrow QRS complex. Methods Homeopathic Digitalis purpurea (Digitalis) was employed to accelerate the patient's heart rate. Results Digitalis caused within 3 days a pulse rate of about 90 beats per minute (bpm) which is represented on the electrocardiogram (ECG) by an accelerated junctional rhythm (AJR).The AJR compelled seeking a medicine to reduce its rate. Homeopathic Arsenicum album (Arsenicum) reduced its rate and also seemed to have assisted in the unanticipated recovery of the atrioventricular node (AVN). Conclusions This case report represents, an ECG documented case of a medical treatment modality which could be an alternative to pacemakers for patients with a HG-AVNB with a narrow QRS complex. Digitalis has been safe and effective during its 3 and a half year employment.

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Differential effects of the blood pressure state on pulse rate variability and heart rate variability in critically ill patients

npj Digital Medicine ◽

10.1038/s41746-021-00447-y ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Elisa Mejía-Mejía ◽

James M. May ◽

Mohamed Elgendi ◽

Panayiotis A. Kyriacou

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Heart Rate Variability ◽

Pulse Rate ◽

Pulse Transit Time ◽

Pulse Rate Variability ◽

Physiological Factors ◽

Ecg Signals ◽

Non Invasive ◽

Electrocardiogram Ecg

AbstractHeart rate variability (HRV) utilizes the electrocardiogram (ECG) and has been widely studied as a non-invasive indicator of cardiac autonomic activity. Pulse rate variability (PRV) utilizes photoplethysmography (PPG) and recently has been used as a surrogate for HRV. Several studies have found that PRV is not entirely valid as an estimation of HRV and that several physiological factors, including the pulse transit time (PTT) and blood pressure (BP) changes, may affect PRV differently than HRV. This study aimed to assess the relationship between PRV and HRV under different BP states: hypotension, normotension, and hypertension. Using the MIMIC III database, 5 min segments of PPG and ECG signals were used to extract PRV and HRV, respectively. Several time-domain, frequency-domain, and nonlinear indices were obtained from these signals. Bland–Altman analysis, correlation analysis, and Friedman rank sum tests were used to compare HRV and PRV in each state, and PRV and HRV indices were compared among BP states using Kruskal–Wallis tests. The findings indicated that there were differences between PRV and HRV, especially in short-term and nonlinear indices, and although PRV and HRV were altered in a similar manner when there was a change in BP, PRV seemed to be more sensitive to these changes.

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Time Course of ECG Depolarization and Repolarization Changes during Ischemia in PTCA Recordings

Methods of Information in Medicine ◽

10.1055/s-0038-1633832 ◽

2004 ◽

Vol 43 (01) ◽

pp. 43-46 ◽

Cited By ~ 9

Author(s):

J. García ◽

G. Wagner ◽

R. Bailón ◽

L. Sörnmo ◽

P. Laguna ◽

...

Keyword(s):

Time Course ◽

Wave Amplitude ◽

Temporal Evolution ◽

Delayed Response ◽

S Wave ◽

Ecg Changes ◽

T Complex ◽

Karhunen Loeve Transform ◽

Low Amplitude ◽

Electrocardiogram Ecg

Summary Objectives: In this work we studied the temporal evolution of changes in the electrocardiogram (ECG) as a consequence of the induced ischemia during prolonged coronary angioplasty, comparing the time course of indexes reflecting depolarization and those reflecting repolarization. Methods: We considered both local (measured at specific points of the ECG) and global (obtained from the Karhunen-Loève transform) indexes. In particular, the evolution of Q, R and S wave amplitudes during ischemia was analyzed with respect to classical indexes such as ST level. As a measurement of sensitivity we used an Ischemic Changes Sensor (ICS), which reflects the capacity of an index to detect changes in the ECG. Results: The results showed that, in leads with low-amplitude ST-T complexes, the S wave amplitude was more sensitive in detecting ischemia than was the commonly used index ST60. It was found that in such leads the S wave amplitude initially exhibited a delayed response to ischemia when compared to ST60, but its performance was better from the second minute of occlusion. The global indexes describing the ST-T complex were, in terms of the ICS, superior to the S wave amplitude for ischemia detection. Conclusions: Ischemic ECG changes occur both at repolarization and depolarization, with alterations in the depolarization period appearing later in time. Local indexes are less sensitive to ischemia than global ones.

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Data Independent Acquisition Based Bi-Directional Deep Networks for Biometric ECG Authentication

Applied Sciences ◽

10.3390/app11031125 ◽

2021 ◽

Vol 11 (3) ◽

pp. 1125

Author(s):

Htet Myet Lynn ◽

Pankoo Kim ◽

Sung Bum Pan

Keyword(s):

Short Term Memory ◽

Feature Learning ◽

Biometric Authentication ◽

Qrs Complex ◽

Data Types ◽

Ecg Signals ◽

Data Independent Acquisition ◽

Deep Networks ◽

Classification Tasks ◽

Electrocardiogram Ecg

In this report, the study of non-fiducial based approaches for Electrocardiogram(ECG) biometric authentication is examined, and several excessive techniques are proposed to perform comparative experiments for evaluating the best possible approach for all the classification tasks. Non-fiducial methods are designed to extract the discriminative information of a signal without annotating fiducial points. However, this process requires peak detection to identify a heartbeat signal. Based on recent studies that usually rely on heartbeat segmentation, QRS detection is required, and the process can be complicated for ECG signals for which the QRS complex is absent. Thus, many studies only conduct biometric authentication tasks on ECG signals with QRS complexes, and are hindered by similar limitations. To overcome this issue, we proposed a data-independent acquisition method to facilitate highly generalizable signal processing and feature learning processes. This is achieved by enhancing random segmentation to avoid complicated fiducial feature extraction, along with auto-correlation to eliminate the phase difference due to random segmentation. Subsequently, a bidirectional recurrent neural network (RNN) with long short-term memory (LSTM) deep networks is utilized to automatically learn the features associated with the signal and to perform an authentication task. The experimental results suggest that the proposed data-independent approach using a BLSTM network achieves a relatively high classification accuracy for every dataset relative to the compared techniques. Moreover, it exhibited a significantly higher accuracy rate in experiments using ECG signals without the QRS complex. The results also revealed that data-dependent methods can only perform well for specified data types and amendments of data variations, whereas the presented approach can also be considered for generalization to other quasi-periodical biometric signal-based classification tasks in future studies.

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Heart rate variability, autonomic regulation and myocardial ischemia

International Journal of Cardiology ◽

10.1016/j.ijcard.2020.03.012 ◽

2020 ◽

Vol 312 ◽

pp. 22-23

Author(s):

Daniela Lucini ◽

Massimo Pagani

Keyword(s):

Heart Rate ◽

Heart Rate Variability ◽

Myocardial Ischemia ◽

Autonomic Regulation

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A Trigonometric Projection Method for Overcoming High Intensity Heart Rate Caused Waveform Deformation in Electrocardiogram Biometrics

Journal of Medical and Biological Engineering ◽

10.1007/s40846-021-00617-z ◽

2021 ◽

Author(s):

Tsu-Wang Shen ◽

Shan-Chun Chang

Keyword(s):

Heart Rate ◽

High Intensity ◽

Correlation Coefficients ◽

Calibration Method ◽

Mean Square ◽

Biometric Technology ◽

Overall Performance ◽

Electrocardiogram Signal ◽

Mean Square Difference ◽

Electrocardiogram Ecg

Abstract Purpose Although electrocardiogram (ECG) has been proven as a biometric for human identification, applying biometric technology remains challenging with diverse heart rate circumstances in which high intensity heart rate caused waveform deformation may not be known in advance when ECG templates are registered. Methods A calibration method that calculates the ratio of the length of an unidentified electrocardiogram signal to the length of an electrocardiogram template is proposed in this paper. Next, the R peak is used as an axis anchor point of a trigonometric projection (TP) to attain the displacement value. Finally, the unidentified ECG signal is calibrated according to the generated trigonometric value, which corresponds to the trigonometric projection degree of the ratio and the attained displacement measurement. Results The results reveal that the proposed method provides superior overall performance compared with that of the conventional downsampling method, based on the percentage root mean square difference (PRD), correlation coefficients, and mean square error (MSE). Conclusion The curve fitting equation directly maps from the heart rate levels to the TP degree without prior registration information. The proposed ECG calibration method offers a more robust system against heart rate interference when conducting ECG identification.

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Origins of heart rate variability: relationship of heart rate burst morphology to work duration and load

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1999.277.4.h1491 ◽

1999 ◽

Vol 277 (4) ◽

pp. H1491-H1497

Author(s):

Daniel Roach ◽

Robert Haennel ◽

Mary Lou Koshman ◽

Robert Sheldon

Keyword(s):

Heart Rate ◽

Burst Duration ◽

Heart Period ◽

Quantal Response ◽

Ambulatory Ecg ◽

Work Duration ◽

Baroreceptor Activation ◽

Relationship Of ◽

Electrocardiogram Ecg ◽

The Impact

We are developing a lexicon of specific heart period changes, or lexons, that recur frequently and whose physiological meaning can be read into ambulatory electrocardiogram (ECG). The transient, reversible “burst” of tachycardia induced by exercise initiation can also be seen on ambulatory ECG. We hypothesized that burst morphology depended on the work that preceded it and on baroreceptor activation. Ten subjects with mean age 38 yr (range 17–69 yr) underwent two protocols of semisupine cycling in which load and duration were varied. Burst duration increased with longer cycling times (median values of 18.0, 25.5, and 23.7 s with 1, 3, and 5 s of cycling, respectively; P= 0.033). Burst shape as assessed by heart period exponential decay constant and burst magnitude did not change. To assess the impact of workload, subjects cycled for 5 s at loads of 0, 25, 50, and 75 W. No significant differences were seen in burst duration, burst magnitude, or burst shape. Tachycardia preceded hypotension by 4.6 ± 2.2 s, which is inconsistent with baroreceptor involvement in the onset of burst tachycardia. Because burst morphology is a nearly quantal response to the initiation of exercise, the presence of a burst on an ambulatory ECG implies the onset of exercise.

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